A recent change of rules means resolutions have to be posted on the organisation's website 60 days before meetings begin, so we have more advance notice of countries' real intentions than formerly.

The Latin American bloc - known as the Buenos Aires Group for these purposes - has lodged a bid to create a whale sanctuary in the South Atlantic Ocean.

Japan has set down a motion reserving its right to request a commercial or quasi-commercial hunting quota for minke whales in its coastal waters.

Monaco is looking for the IWC to refer whale protection to the UN; and, as happens every five years, various countries will be seeking to extend subsistence hunting permits for indigenous communities, mainly in the Arctic.

The South Atlantic sanctuary and Japan's coastal whaling bid have both been tabled year after year.

Mutual acceptance of these proposals was one of the main elements of the "peace package" that countries pursued for three years before admitting at the 2010 meeting that minds couldn't quite meet.

But the two main blocs within the IWC don't agree on where the process formally known as the Future of the IWC is now.

When I spoke during the week to Brazil's commissioner to the IWC, Marcos Vinicius Pinta Gama, he described the compromise package as "dead", and I have heard the same thing from several European delegates.

Japan: Back in the game

But Japan's deputy commissioner Akima Umezawa disagreed.

"Look at last year's report - it says we should continue dialogue, continue to build trust and encourage continued co-operation," he said.

"So the Future of the IWC process is not dead."

So here is part of what makes this year's cocktail of resolutions potentially explosive.

During the course of the Future of the IWC negotiations, governments agreed that they would not put resolutions to the vote, but try for consensus.

IWC rules mean that most important changes require a three-quarters majority - and with the commission split roughly 50-50 into countries that oppose whaling and those that vote for its continuance, the prospects of critical measures being passed are somewhere near zero.

Last year, despite the maths, the Latin American bloc insisted on its right to put the whale sanctuary proposal to a vote.

Japan and its allies said this was a breach of faith, as they had been prepared to accept the sanctuary bid as long as it was part of a compromise package.

So they walked out - which the anti-whaling bloc regarded as a breach of faith. A recent communique from the Buenos Aires Group called it "abusive behaviour".

There came the somewhat surreal realisation that no-one knew how a quorum was defined in IWC rules.

And after a year's discussion within a small working group, it's clear that as yet there is still no agreed definition.

You might think it should be a simple question to settle.

But in the febrile and anarchic world of whaling, it's become politicised, with different blocs arguing for the position that suits them best.

In order to get last year's meeting closed, the compromise was that the sanctuary vote would be held over until this year, when it will be the first substantive item on the agenda.

And Mr Pinta Gama told me that the Latin American bloc is not intending to hold back.

"We hope common sense will prevail, that we'll be able to have a normal meeting with clear rules including the one on the quorum, and that we'll be able to take a decision on this [sanctuary] proposal that has been on the table for many years.

"It's going to be difficult, we know, but we think that we have to pursue this objective."

Dr Umezawa, however, was equally clear that the sanctuary bid will not enjoy the support of the pro-whaling countries.

"There is simply no scientific evidence for the sanctuary proposal... there is no need for a sanctuary while the [commercial whaling] moratorium is in effect, and anyway no whaling takes place within the boundary of the proposed sanctuary," he said.

"And the proposal is part of the Future of the IWC package; so we cannot accept cherry-picking."

The language of Japan's coastal whaling proposal hints that it will table a vote on it if the Buenos Aires Group presses for a vote on the South Atlantic sanctuary.

But before any vote takes place, the commissioners have to decide their definition of a quorum. And based on previous experience, that could take a while - perhaps even a majority of the meeting, given the politicised nature of the dispute.

"Nobody wants a repeat of last year because that was a poor show, and deeply undermines the credibility of the commission," observed the long-time commissioner for Monaco, Frederic Briand.

"Should we again get involved in a procedural war at the meeting in Panama, all hopes would be lost that the IWC could properly function."

A long procedural wrangle would matter outside the IWC too.

Every moment spent on what a quorum means is a moment less that can be used to discuss substantive issues that are already struggling to get a decent hearing, such as the growing impact of ocean noise on cetaceans and the implications of climate change.

And the countries pursuing subsistence quotas for their indigenous groups - Russia, Denmark (on behalf of Greenland), St Vincent and the Grenadines, and above all the US - will be stalked by the spectre of 2002, when a political stand-off put the future of subsistence whaling at risk.

The picture of an IWC heading back to the dysfunctional, squabbling days before the "peace process" is one that many find unappealing.

Guide to the Great Whales

And that's why Monaco's Frederic Briand - with the support of many other anti-whaling countries - has tabled a motion that would see whale conservation "sent upstairs" to the UN.

"We have a moratorium on commercial whaling that's been in place for at least 25 years, but we see it's business as usual for the whaling countries," he said.

"Despite the moratorium, about 35,000 whales have keen killed by three countries. So there's a failure of the IWC to enforce its own resolutions."

His camp believes a change of scene is also needed because the IWC numbers less than half of the world's countries among its members, and deals with less than half of the world's cetacean species.

"Our proposal at the UN will embrace all highly migratory species of cetacean," he said. "In some regions they are currently protected by marine protected areas, and in others they're killed - this is a nonsense."

The draft resolution "Invites the forthcoming UN General Assembly to consider this question in the context of outstanding issues relating to Oceans and the Law of the Sea, with a view to promoting good order in the oceans in compliance with Principle 15 of the Rio Declaration."

This resolution only needs a simple majority to pass, and so the odds ought to be in its favour given that anti-whaling countries currently make up more than half of the commission.

However, the EU always votes as a bloc in the IWC now, and must decide what to do by consensus. And there is a theory that Denmark may hold out against the rest of the EU, as it has done before, if it feels that subsistence quotas for the Greenland Inuit are under threat.

Politics, politics, politics; the waters of the IWC are riddled with it.

Ever since I began covering the issue back in 2005 there have been regular mutterings about whether the IWC has a future; yet so far it's endured, with most member countries seeing collapse as a last resort.

But if delegates in Panama spend days locked in meetings where wrangling about the definition of a quorum is used as a proxy for much more fundamental divisions... what then?

Last December's UN climate summit, in the South African port of Durban, saw heated discussions on a proposal that governments should commit to agreeing a new comprehensive global emissions-limiting deal with some kind of legal force before 2015.

Reluctant nations found themselves up against a burgeoning coalition of principally small countries from the developed and developing worlds alike, which found common interest in tackling climate change as quickly as possible.

The rainbow coalition included the EU, the Least Developed Countries (LDCs), small islands vulnerable to impacts such as rising sea levels, and progressive Latin American countries such as Costa Rica.

The giant container ships steaming into and out of the Durban docks were matched stylistically by the delegations striding from conference room to conference room, their beetle brows and purposeful gaits testament to the precious cargo they might deliver.

And deliver they did, eventually, with governments committing to agree a new global deal by 2015 and have it in force by 2020, with every country included.

But it was just a promise; and promises have been broken before on the wheels of realpolitik.

Since Durban, real world issues have begun to bear down on those leading the charge towards that new global deal.

Recession continues to stalk the eurozone. And even though many European governments say green measures will not impoverish them further and may even make them richer, few are acting as though they believe it.

Opposition to the inclusion of international aviation within the EU Emission Trading Scheme (ETS) from countries such as China, the US and Russia has increased. As a result some European governments and senior EU officials fear a trade war could be triggered with nations that include eurozone creditors.

Meanwhile, environment ministers and officials from the smaller developing countries are increasingly engaged not with the UN climate process, but with preparations for June's Rio+20 summit.

And here they are finding that on issues such as overseas aid contributions, Europe is not always behaving as the friend it appeared to be in Durban.

That issue carries over into the climate change discussions, because here too the rich world has promised money - $100bn per year by 2020 - and if pledges are not being met in the arena of overseas aid, why should those developing countries believe pledges will be met in the climate context?

Just five months on, the Durban coalition is a little battered.

On Monday and Tuesday in Brussels, at least 30 of the coalition's key members will meet to re-state their Durban commitment and talk about some of the key steps they can take in the short term to give the 2015 process some momentum.

That's an urgent priority, as the first meeting of the working group on the new process (the Durban Platform) is just a couple of weeks away and the visions of various countries on how it should progress are very different.

They'll be talking about what needs to be done to ensure that an adequate proposal goes on the table at the next UN climate summit, in Qatar in December, for putting EU emission cuts (and possibly others too) under the Kyoto Protocol.

They'll need to discuss how the 2015 deal can bring all countries into a new agreement that will eventually regulate emissions from all countries, yet contains the principle of equity at its heart, allowing poor countries room to emit carbon as they develop.

They'll be trying to navigate the remaining hurdles to fully implementing new international schemes to bring financial support and clean technology from developed countries to their poorer counterparts.

And they'll discuss Rio+20 as well - not least because some of the proposals on the table there, such as a goal to double the global share of renewable energy by 2030 and moves to make agriculture more sustainable, would by themselves slow the rise of the world's greenhouse gas emissions.

Along the way, they'll be hoping to pick up a few countries such as Australia that didn't make it clear in Durban whether they belonged to the group pushing for the new deal or the one being pulled towards it reluctantly.

Ministers and officials will be coming to Brussels fresh from an informal two-day session at UN climate convention headquarters in Bonn, where they've heard United Nations Environment Programme chief scientist Joseph Alcamo outline a few key issues.

He told delegates that steps such as setting tighter rules on car emissions, regulating for energy efficient goods and building urban mass transit systems are already having an impact that can be measured.

But he also said that without much faster uptake of such measures, the best estimate for the year 2100 would be a world that is on average 2.5-5C warmer than in pre-industrial times.

Governments have heard such messages plenty of times before, of course.

And they're likely to hear them louder than ever next year when the Intergovernmental Panel on Climate Change (IPCC) publishes the first instalment of its fifth Assessment Report, which is likely to forecast harsher impacts ahead on factors such as sea level rise than the previous edition.

The geopolitics are not auspicious for a massive, game-changing leap on climate change this year.

China is preparing for a change of leadership later this year, with President Hu Jintao and other senior figures set to step down. Presidential elections in the US and in France could usher in a major change of direction.

So the priority is to get things right on the deliverables. And the current Danish EU presidency offers a window to do that, with its energetic Climate Minister Martin Lidegaard working alongside his predecessor Connie Hedegaard, now EU Climate Commissioner, in a co-ordinated push.

South Africa's International Relations Minister Maite Nkoana-Mashabane, who chaired the Durban talks, said recently it was vital that "the gains made in Durban are not rolled back by being overwhelmed by the enormity of the problem and the task at hand".

Hence the importance of the Brussels meeting, small and select though it is, as an opportunity to re-focus and re-energise - to get the small things right, and establish a framework for the bigger political negotiations that lie ahead.

"There is no doubt that Member States are working extremely hard to ensure that world leaders renew political commitments for sustainable development at Rio+20," he writes.

As he notes in his post, and as many other observers have maintained along the way, an outcome that puts our global society on a truly sustainable footing needs to contain more than generalities, platitudes and a wish-list.

One example concerns energy. The G20 has declared on several occasions that fossil fuel subsidies should end; Rio+20 has the potential to set a timetable.

Marine protection in waters beyond national jurisdiction, an upgrading of the UN Environment Programme's status, and a comprehensive programme on ocean acidification are among other concrete measures that have been suggested.

We're now into the second round of informal consultations on the "zero draft", the initial draft outcome document drawn up by the co-chairs of the process.

And reports back from environment groups observing the talks in New York present a different narrative from Mr Sha's - a narrative in which the zero draft is being watered down rather than enhanced.

The first thing to say is that it's a lengthy and complex process in which various blocs of countries test the water, deploy negotiating tactics and conceal their true hands - all of which contributes to the fact that so many of these negotiations go well beyond the wire, in this case the end of Friday 22 June, Rio de Janeiro time.

At one stage, the text had swollen from its initial 19 pages to 278, after governments submitted amendments, revisions, and alternative wordings.

Now it's coming down again - to just 157 last Friday - which is certainly good for the sanity of anyone trying to make sense of it, and presumably for anyone involved in the discussions as well.

And we're clearly still very much in that preliminary skirmishing phase. With talks continuing, some of what I've written may be out of date by the time you read it.

But I think some trends and some sticking points are discernible.

Money is shaping up to be a big issue.

As in the UN climate change and biodiversity negotiations, developing countries are saying here that they'll take on board green ideas - but at a price.

At one point, the powerful G77/China bloc of 131 developing countries suggested that the outcome document should explicitly speak of the need to mobilise "necessary and predictable resources" of an unspecified amount by 2020 "for meeting the goals" agreed at Rio+20.

Bearing in mind that recent climate change and biodiversity agreements both talk of sums in the order of $100bn per year by 2020, and that the Rio+20 agenda is far broader, you can guess at the sums of money that might be requested here.

Developed nations that would be expected to foot the bill are opposing such a clause. Many are in severe debt, with China itself holding a sizeable proportion of the IOUs.

But developed nations such as the US, Japan and parts of Europe have been resisting attempts to include language that would admit they're failing to meet existing pledges on finance, such as providing 0.7% of GDP in overseas aid.

The zero draft's simple commitment to phasing out "environmentally harmful" subsidies on things like fossil fuels, fisheries and agriculture is also being slowly weakened.

The idea that a fossil fuel subsidy phase-out should be gradual so as to prevent damaging impacts on poor societies clearly has social merit; but there's no reference to the phase-out happening faster in rich countries.

Japan and the US have tried to delete language on ending agricultural and fisheries subsidies. Canada wants fossil fuel subsidies to end only when they are inefficient and cause "wasteful" consumption.

A number of blocs including the EU have suggested "rationalisation" rather than "elimination" of subsidies. Firm targets and timetables remain elusive.

There's been an apparent back-sliding on the overall energy package suggested by UN Secretary-General Ban Ki-moon - universal access to modern energy, a doubling in the rate of energy efficiency improvement, and a doubling of the renewables share, all by 2030.

Whereas the zero draft talked of "building on" that vision, a version from last week's discussion would have the Rio+20 summit merely "taking note" of it.

Developed countries also appear to be mounting something of a co-ordinated attack on access and benefit sharing (ABS).

In essence, if a company from a rich country takes a natural resource from a poor country and makes billions from it, they should have to give something back.

The fine detail of this issue became the major bone of contention at the 2010 UN biodiversity convention meeting; and in the Rio+20 process, references are being deleted by countries including the US, New Zealand and Canada.

On the social side, there are some interesting positions being taken.

Iceland, for example, has proposed a goal of having at least 40% of "leadership positions" reserved for women. The Vatican has taken a stand against the proposed universal right to education including references to gender equality, family planning and reproductive health.

Perhaps most fundamentally, the basic Rio+20 premise that things need to be done differently in future does not appear to be universally shared, with the G77/China arguing that economic growth in developing countries is not only the best way to eradicate poverty and hunger, but also to restore harmony with nature.

With April yielding before May's advances, less than eight weeks remain before a summit that some insist is the final chance to reform society's currently unsustainable processes.

Does this look like a recipe adequate for such reform?

To the outside, it often seems to take place in an environment where entrenched beliefs are more important to some protagonists as evidence.

A paper in the journal Nature this week aims to put that right, with a comprehensive and rigorous analysis of studies done on crop yields.

The researchers, from McGill University in Canada and the University of Minnesota in the US, looked for studies that met pretty stiff quality criteria.

To be included, a study had to compare organic and conventional planting across similarly-sized areas, had to report on the sample size and error margins, and had to use organic methods that complied with the guidelines of certification organisations (such as the UK's Soil Association).

The headline conclusion is pretty unequivocal; across the board, organic farming produces lower yields than conventional methods, by about 25%.

For fruit, the difference is marginal, just a few percent. But for vegetables, organic yields are about 33% down on conventional, with barley and wheat a little lower still.

There are further differences depending on what type of soil is in play; and there's a steer that some of the enhanced performance of conventional cropping comes through better irrigation.

There's a growing body of evidence showing that in order to provide the extra food needed by the bigger and richer human population of the near future - a doubling of demand by 2050 - without destroying forests and wetlands, farming needs to be made more intensive.

So on the face of it, this latest analysis is a vote for conventional methods above organic.

This would be a slap in the face for people who choose to eat organic food because they believe it's better environmentally - though not for those who choose on the claimed health or taste benefits.

But the fact is that yields are just one aspect of the much larger debate about the farms of the future.

Conventional farming methods using conventional fertilisers are adding active nitrogen to the soil, which tends to move to other places - lakes, rivers, seas, the air.

And according to the Planetary Boundaries concept, the nitrogen cycle is already one of the places where humanity has already broken through the "safe limit".

Conventional farming is likely to be harder on insects such as bees - which we know are already in trouble in many countries, partly through use of insecticides that organic farming systems should avoid.

More complex still is the social side of agriculture.

In some countries if not in all, organic farms tend to be smaller than their conventional neighbours.

They're likely to be less mechanised, and to produce goods that command higher prices.

All of which is very good for the social side of agriculture - boosting employment (in the same way that artisanal fishing provides more jobs than the industrial kind), promoting local ownership of land and, in the poorest countries, mitigating against land-grabs.

Just to make things more convoluted, food production and distribution is now an internationalised system.

If Western consumers demand organic food among their imports, is that foisting an inappropriate standard upon growers in poor countries, or is it potentially helping to set better standards for farmers' health and welfare in the exporting country?

It's a rich smorgasbord of issues alright. And yields, as you might say, are not the only fruit.

The margin of the vote was huge - 78-0 - indicating that all political parties have found common ground on this issue.

Now all that's needed is the signature of President Felipe Calderon, which is expected to materialise next week.

The bill enshrines a number of measures in law, including:

The targets look pretty demanding at first sight - especially for a country where the population is growing and the economy expanding, and where oil makes a significant contribution to the national coffers.

So why is it taking steps that to the eyes of many will probably look like economic suicide?

I had a chance to ask three Mexican parliamentarians recently when they came to London to look at how the UK, the first country in the world with this sort of national legislation, is doing it.

The views of Eric Luis Rubio Barthell, Nicolas Bellizia Aboaf and Porfirio Munoz Ledo were quite diverse - perhaps not surprising, as they come from different political parties.

"Mexico has a long tradition in multilateral politics," said Mr Munoz Ledo, a founder member of the centre-left Democratic Revolution Party (PRD) who now chairs the Foreign Affairs Commission.

That tradition re-asserted itself at the UN climate summit in Cancun in 2010, he said - and "this legislation is a strong commitment coming out of Cancun" to reflect that international commitment on climate change in national legislation.

For Mr Bellizia Aboaf, a member of the Institutional Revolutionary Party (PRI), which despite its name is considered more of a centrist party these days, it was more about practical issues.

"My state of Tabasco has suffered quite heavily the consequences of climate change," he said.

Low-lying Tabasco has traditionally suffered from flooding but the events of 2007, when water covered 80% of the state, were especially severe.

Yet Tabasco also has nearly 1,000 oil and gas wells in operation - a microcosm of Mexico in general, which is the sixth largest oil exporter in the world.

Traditionally, big hydrocarbon-producing countries have fought tooth and nail against action on climate change; and Mr Rubio Barthell, also of the PRI, said Middle Eastern oil-exporting countries have repeatedly asked Mexico to take this stance too.

But as the country has developed, oil and gas have become progressively less important to the economy as a whole.

That's why a more green economic vision makes sense for a number of politicians.

"I personally think this climate change topic should be an economic and energy issue, not an ecological issue, though I recognise that opinions are divided on this," said Mr Rubio Barthell.

And for Mr Munoz Ledo, the transition implied by a 35% renewable energy target is necessary and absolutely achievable.

"Mexico is aware this is the end of the oil era, so we need to implement this fiscal reform - and if we go through it, we'll be able to do without this oil," he said.

Solar energy, hydro-electricity, geothermal, biofuels and nuclear are options that are going to be explored.

The irony is, of course, that Mexico has traditionally been a younger and poorer cousin of the giant to its north, the United States, which has repeatedly declined to establish legislation of anything like this strength, citing impacts on economic growth.

"Power for the US is based on the army and energy and oil," Mr Munoz Ledo said.

"In 1989 you had [George] Bush senior coming into office from an oil background; if you go through Clinton and Obama, they serve the oil interest first.

"We're talking about the politics of neo-liberalism here which is based on oil interests and indebtedness - this is why so many in the US don't accept climate change, even though it's based on scientific evidence."

The three parliamentarians came to the UK to learn from its experience in setting up a robust carbon-curbing system, and pick up ideas.

Mr Bellizia Aboaf cited the Committee on Climate Change, which advises the government and monitors its actions, and the Carbon Trust that promotes low-carbon technologies, as bodies of interest, and also the UK experience with public-private funding models.

There are two big differences between the two nations' laws.

Firstly, as a developing country, Mexico isn't cutting emissions but cutting the rate at which they'll rise.

Secondly, it will require international financial support to deliver its targets - as is mandated in the UN climate convention.

The Cancun summit agreed to establish an international Green Climate Fund that is supposed to provide much of that support.

But some of its details have yet to be finalised, and it is a long way from receiving the huge sums of money it is supposed to receive - maybe $100bn a year by 2020 - so whether Mexico will get the support it needs is, for now, an open question.

Although Messrs Munoz Ledo, Rubio Barthell and Bellizia Aboaf appeared to find their London trip fruitful, I couldn't help feeling they were looking forward to getting back to the less frigid climes of Mexico, where solar power - as they remarked - seems a much more viable venture.

We didn't ask for them, we didn't know much about them. Fuelled by tales of superweeds, Franken-foods and mice made sick by eating GM potatoes, we came to not like them very much.

With similar sentiments echoed in most parts of Europe, the region has remained pretty much a GM-free zone, as have many other countries around the world. This endures - despite the fact that there have been no documented cases of people made sick from GM foods, Franken or not.

Fast-forward 20 years, and we may be seeing something similar unfold in the arena of shale gas. Local impacts, in the UK at least, haven't been serious and don't look like being serious.

The two professional geologists on the government-appointed expert panel whose report has just been released agree that the chances of fracking producing an earthquake exceeding magnitude three are slim, as a consequence of the basic geology.

Literally thousands of similar-sized quakes were produced through coal mining, and indeed they continue as the industry's legacy. None has made a building collapse or a road buckle, the geologists said - a bit of plaster falling off a wall, perhaps, but nothing more.

They also report a minimal risk of people finding gas in their drinking water. The gas is too deep, they report, and if it had easy passage to the surface, it would have come up already.

So - you might ask - why the fuss?

Back in 2004 I covered a conference on GM food in Germany, and one of my abiding impressions was the sense of mea culpa from scientists I talked to. Many acknowledged the industry had got its tactics badly wrong in the beginning.

They'd not been open about the technology. They'd kept things under wraps for commercial reasons. They'd explored radical genetic ingredients (scorpion genes in tomatoes, anyone?) with no apparent regard for public reaction. And they were developing terminator technologies - the genetic modification of plants to make them produce sterile seeds - that could have been a lethal weapon to traditional farmers in developing countries.

Companies also presented a blase face on the ecological consequences of growing GM crops, allowing campaigners to narrate a tale of giant menacing alien plants devouring every beetle and blackbird in sight.

The industry has never recovered from this abortive start, in Europe and many other places; and perhaps it never will.

Shale gas appears to have got off to a similar start.

The industry knows exploration may generate small earthquakes - perhaps we shouldn't even call them earthquakes, but tremors - thanks to decades of experience in the US.

Is it open about this up front? Does it actively put this information into the public arena before exploration begins? Does it welcome people onto its sites and brief them on what's likely to happen, and acknowledge the potential for seismic events, while plugging the "cheap energy" line?

Generally, it does not. Which - as with GM, as with the nuclear industry - leaves a huge information void that campaign groups eagerly fill.

Cuadrilla Resources, the company leading the UK's shale gas charge, retains the data it's gathered that indicates how much gas is there; and despite the expert panel's recommendation, it may turn out that all ventures are allowed to keep data on the resources and on seismicity under their control.

As experience shows, this does not promote trust.

Biotech agriculture certainly has its issues, but they're more subtle than the Franken-headlines indicate.

In some locations, with some crops, there are real ecological concerns - but not with all crops in all locations.

The same might turn out to be true with shale gas.

All shale formations are different, and companies will employ a variety of regimes when they frack. The US experience indicates a lot of variability, and some learning through experience.

Presumably European practitioners would learn by doing as well.

But in the biotech agriculture field, campaigners have argued there should be no planting until crops are proven to be "safe" while at the same time wrecking trials that could demonstrate safety, thereby ensuring no take-off.

Shale gas protests around Europe are beginning to see the same kind of dual messaging.

Possibly the biggest real issue around GM crops was that their widespread adoption would set in place agricultural practices that are industrial in nature, based on biodiversity-compromising monocultures, with ownership concentrated in the hands of a few multinational giants.

And the one argument from which shale gas cannot run away is also the one with global, not local, implications.

Quite simply, if Europe invests in shale gas in a big way, it will be almost impossible for the bloc to meet its medium-term climate targets.

The numbers only stack up if shale gas burning is associated with carbon capture and storage.

And with the carbon price bumping along at pretty much an all-time low, that's not going to happen any time soon.

The US and Canada left the Kyoto Protocol partly because investment was flowing into "unconventional" fossil fuel development rather than low-carbon technologies - and once the investment is there, economics dictate that the high-carbon energy has to be used.

No energy source is free of risks, as families of the 7,000-odd Chinese who die every year in coal mines would attest.

No system of food production is without environmental impact either.

You might argue that a more mature debate that takes account of all the arguments and all the nuances would result in better policy - for example, if governments are serious about climate change, allowing shale gas use only when CO2 produced by burning it is captured and stored.

But GM crops failed in the court of public opinion, which tends to be less nuanced than science-based policymaking.

And with opinion polls in many countries showing much more support for renewables than for fossil fuels, politicians pushing shale gas appear to be at odds with their citizens.

Could shale gas in Europe fall at the spectre of minor earthquakes, just as GM crops fell to the vision of health impacts that didn't materialise?

And if it does, would that in the end be a good or a bad thing?

Too young, too mild-mannered (perfect English diction), too much at ease in T-shirt and trousers.

It's a salutary lesson in never judging the book by the cover; because this young Kenyan woman is leading a protest movement that could yet block one of East Africa's most significant infrastructure projects.

The campaign has netted Ms Angelei one of this year's Goldman Prizes, one of the highest annual honours for grassroots environmental activists.

Not that there are too many grass roots in the Turkana region of Kenya, on the border with Ethiopia, South Sudan and Uganda. Rains have been infrequent as far back as communal memory stretches and have become even scarcer in recent years.

The region's prized water resource is Lake Turkana.

It's one of those unusual "endorheic" lakes that has no outflow; water that flows in, and is not used directly, either evaporates or percolates down into aquifers, which in turn provide water for those pastoralists who keep their herds some way distant from the lake itself.

Now, the Ethiopian government is building a major dam, GIBE-3, on the Lower Omo river just over the border. The Omo currently provides about 80% of Lake Turkana's water.

Nearly 240m high, the dam would generate 1,870MW at full flow. It would become the biggest dam in Africa, and the fourth-largest in the world.

Prime Minister Meles Zenawi says it must be built "at any cost" to help Ethiopia electrify and develop, and to power the irrigation schemes and plantations he wants to establish along the Omo valley.

The Kenyan government, which is likely to buy some of the electricity, also supports the scheme.

But Ikal Angelei fears the dam could dry the lifeblood for hundreds of thousands of people in the river valley and around Lake Turkana - lowering the water level by many metres, increasing the already high salinity, and preventing the drainage into aquifers that keeps cattle alive kilometres away.

"Communities that have been benefiting from the flow and the pasture will all have to move to where water is available - you're creating pressure for conflict in an area that already has a high potential for conflict because of scarce resources," she tells me.

"You do anything to change the current balance, you really exacerbate conflict in the region."

The recently increased aridity, combined with population growth, has already brought conflict, some of it across borders.

In 2006, when parts of Turkana had already gone three years without rain and three million Kenyans were on daily food aid, I visited the region briefly.

A local governor told me of pastoralists crossing the border with Uganda in search of somewhere to water their animals, exchanging fire with Ugandan air force planes; hardly a recipe for stability between neighbours.

Last year saw conflict between the Kenyan Turkana people and the Ethiopian Merille.

Ms Angelei does not downplay the development benefits that GIBE-3's electricity could bring, though she does dispute Ethiopian government claims that its impact on Lake Turkana will be negligible.

What she's asking for first is to have the issues discussed thoroughly and openly, with all factors on the table.

The Ethiopian government awarded contracts for building GIBE-3 without tendering - and when this was pointed out to potential funders including the World Bank, European Investment Bank and African Development Bank, they withdrew.

Kenyan law has been another battleground.

She explains that the government is obliged to consider the needs of local people when considering such projects; and as the dam's first Environmental Impact Assessment didn't even mention Lake Turkana and was kept unpublished for years, she argues the government has broken its own law. A case is currently in the courts.

Turkana is among the "cradles of humanity", where our species lived and evolved; so the area has World Heritage interest as well.

Perhaps the most important aspect of the campaign she's mounted with her group Friends of Lake Turkana (FoLT) consists of talking to the communities that make up a variegated and neglected social landscape with a literacy rate barely above 10%.

In 2008, she found, hardly anyone she talked to had heard of GIBE-3 even though it was already underway; many did not even know what a dam was. So much for community engagement and informed consent.

A year later, chiefs and tribal elders signed a declaration authorising FoLT to tackle the Kenyan government on their behalf.

She argues that the governments are looking at the potential economic benefits of the project without understanding its economic costs.

No-one has yet studied the net worth of the fish Lake Turkana produces, the benefits of the cattle pasture - and the costs that society will have to bear if those things disappear.

And there are questions too of whether hydroelectric schemes are the best way to power a region that regularly sees droughts and may in future see them even more frequently as a consequence of man-made climate change.

In 2003, 2008 and 2009 Ethiopia saw regular power cuts because of droughts affecting its existing hydro dams, including GIBE-1 and GIBE-2, which also sit on the Omo river.

"Our prime minister said two years ago that we cannot afford to depend on hydro - but now we're going to buy hydroelectricity from Ethiopia, which is even drier than Kenya," she says.

There's a certain irony in noting that just as Ethiopia is encouraging plantations along the Omo basin of cotton, one of the thirstiest crops and not exactly necessary for food, farmers in Australia's drought-hit Murray-Darling basin are being pressured to give it up.

Success is not assured for Ikal Angelei's campaign.

But even if it fails, it will have created a more informed local society, brought governments closer to the position of having to observe their own environmental laws, and made it more difficult to finance projects with dubious credentials.

This year's other Goldman Prizewinners are:

Each wins $150,000 for his/her campaign, as well as having the chance to raise the profile of the issues on which they work.

In doing so, each has the chance to follow in the footsteps of the late Kenyan campaigner Wangari Maathai, who won the Goldman Prize in 1991 en route to entering parliament, becoming environment minister and the first environmental Nobel Peace laureate.

"Wangari's fight made us believe that the efforts of one person can go a long way," says Ikal Angelei.

"For me, when I started this campaign in 2008 it was a one-person fight, most people didn't understand what I was doing, my own family thought I was crazy.

"But seeing the impact it's had, the legacy - it's leaving behind a situation where communities are actually believing 'you know what, we can fight for ourselves' - that has been a great inspiration."

The story has so far been told from the human point of view, and why not - clearly it's very much a safety issue when you have inflammable gas percolating up through the sea, and some of the same gas on fire as it emerges from a stack on top of the Elgin rig.

With all the workers now off the rig, scientists are starting to look at the ecological effect of having so much gas bubbling into the water column.

They're the same type of questions that were asked in the aftermath of the Deepwater Horizon disaster in the Gulf of Mexico, and when the stricken Fukushima nuclear power station began flushing radioactive elements into the oceans just over a year ago.

Elgin field gas is mainly methane - the stuff we burn in our cookers - but it also contains related substances: propane and butane, as well as others such as hydrogen sulphide.

A "sheen" of condensate from this is apparently lying on the sea surface, containing up to about 20 tonnes of material.

What's of more concern ecologically is what impact the gases may have had as they bubbled up through the water, in quantities that have not yet been evaluated.

The UK Department of Energy and Climate Change (Decc) said "there is no indication of a risk of significant pollution to the environment".

Not all scientists are as sanguine.

"Methane and hydrogen sulphide, when dissolved in water, are highly toxic to most higher forms of marine life," said Christoph Gertler, who studies bioremediation at Bangor University.

"It can be assumed that fish will avoid the area immediately affected by the spill, but in any case the effects of hydrogen sulphide and methane are more acute than chronic, and there should be no accumulation in the food chain."

Perhaps no long-term impact, then, but a possible short-term shock.

We're nearly two years on from the Deepwater Horizon disaster, which saw oil (along with gases such as methane) streaming into the Gulf of Mexico at rates of about 40,000 barrels a day for months. The impact on the coastline was starkly seen through oiled pelicans, dead seagrasses, and slicks stretching for miles.

But underwater was a different matter. Only now is it becoming clear.

Last week the US National Oceanic and Atmospheric Administration (Noaa) said: "Since February 2010, more than 675 dolphins have stranded in the northern Gulf of Mexico - a much higher rate than the usual average of 74 dolphins per year."

Further along the coast, away from the peak oil plume, stranding rates are normal.

Noaa has declared this an Unusual Mortality Event and is investigating the causes of death. The main clue so far is that some of the dolphins show significant imbalances in hormone levels.

In one sense this is really surprising. Dolphins are among the most intelligent marine animals, highly mobile and adaptable.

So why didn't they take evasive action? There are several possible explanations.

You might also ask what the impacts are likely to be on other less intelligent, less mobile and less adaptable creatures.

The gulf is a spawning ground for fish including bluefin tuna; before too long we may discover whether Deepwater Horizon affected spawning during the 2010 Spring.

Half a world away, meanwhile, the impacts of the Fukushima outflow on marine life are equally hard to measure, but appear so far to be negligible.

In October, a US-Japanese research team published a scientific paper concluding that although much more research remained to be done, there appeared to be "minimal impact on marine biota or humans due to direct exposure [to radioactive nuclides] in surrounding ocean waters".

And just last month, one of the scientists involved, Ken Buesseler, told a US scientific meeting that although elements from Fukushima could be detected in organisms 600km from the stricken power station, their radioactivity was dwarfed by the natural radioactivity in seawater.

Bans on fishing and on eating fish remain in place, and Japan is setting tighter limits for acceptable levels of radioactive contamination in seafood products.

But overall, Fukushima - the largest ever release of radioactive material to the oceans apart from nuclear bomb explosions - has produced no impact on marine life that has yet been discerned.

(And plans to build a wind farm near Fukushima to replace lost electricity generation capacity and regional employment are under attack from fishermen, who fear the turbine towers will damage their generally productive fishing grounds.)

Meanwhile, marine mammals in the Arctic carry mercury levels high enough that they make toxic eating for indigenous peoples who have traditionally consumed them. The main anthropogenic source of mercury is coal burning, the heavy metal sent up power station chimneys and carried polewards on the wind.

We all need energy of some kind - and the global demand is set to increase as both the human population and our consumption grow.

So ecological footprint is a key factor in determining which energy sources to use - which is why we need to carefully dissect the impact of accidents such as Elgin, Deepwater Horizon and Fukushima.

The two professors have been working together on a State of the Planet report, which has involved trawling through numerous reports and scientific papers. At the end of it all, the message of one appears somewhat optimistic, the other fundamentally pessimistic.

They agree that changes to the world since about 1950 have been startling - rapid spread of the human population, accelerating exploitation of forests and marine resources, surging economic growth in successive waves across the world, and so on.

This radical reshaping of the natural world by a single species is certainly unprecedented in Earth history, which a few years back led to scientists Paul Crutzen and Eugene Stoermer coining a special name for our epoch - the Anthropocene.

(The Planet under Pressure organisers have made an animated video of humanity's journey of expansion, by the way, which you can see here.)

If you accept the premise that we have entered the Anthropocene, one of the over-arching questions is "what happens now?"; another is "can we get out of it?"

Prof Liverman, who studies social aspects of global change at the University of Arizona, has the task of assessing the societal trends that either indicate we're heading further into Anthropocene territory or beginning to back out.

Since 2000, she says, some trends have begun to reverse - in particular human fertility, which has halved globally in the past few decades as women have had progressively more access to family planning and maternal health services. In time, this should see the global population stabilise.

There has been a change in food production too.

"In agriculture, the big idea used to be that we destroyed tropical forests [in order to raise food production]," she says.

"What we've seen is that is turning around in some parts of the world where people are growing more food without encroaching on forests - in countries such as Vietnam, the forests are starting to return."

The carbon intensity of industry has reduced too. Companies are finding ways of doing business that are more frugal with energy than before, and saving money in the process.

As a physical scientist, Prof Steffen's role is to see whether these changing human trends are reflected in the condition of the natural world - the oceans, the atmosphere, the land. Overwhelmingly not, he says.

"Over the last decade, with a couple of exceptions we cannot yet see any effect of these trends on the human side. CO2 emissions increased by a larger rate post-2000 than pre-2000 even though we're more efficient - it's just swamped by rising consumption."

The main exception is ozone depletion, which has been arrested, if not yet reversed, by the Montreal Protocol.

Other than that, we appear to be heading deeper and deeper into the Anthropocene. But what does that mean?

No-one really knows. The trends driving global change are unprecedented, so history can give only hints, not a full answer.

Computer models struggle to give precise answers even on single issues, such as climate change or the response of ocean ecosystems to temperature change.

There's a lot of talk about runaway effects. It's said, with some evidence to back it up, that warming and deforestation in the Amazon could combine to create feedbacks that destroy the forest, or that the Greenland ice sheet could begin to melt irreversibly.

Prof Steffen raises another possibility - that the Earth system will stabilise again, but under a different set of conditions, which would be a lot less suitable for the whole range of nature that we find today.

This conference, Planet Under Pressure, has assembled several thousand delegates from academia, business, campaign groups, and the occasional government representative.

It's designed to get people from science and the policy field together three months before the Rio+20 summit in June, to discuss where we are, where we might be going, and how the supertanker workings of our global society can be turned round, if that's what needs doing.

Much of what I've so far read and heard, though, seems very familiar:

Will one more conference, one more set of reports and - in June - one more global summit bring about these changes?

At the end of Monday's morning session, conference host Nisha Pillai asked the packed hall of delegates for a show of hands on this most basic question - will the changes that "we need" happen?

The noes outvoted the ayes.

Best wishes for a balmy Anthropocene.

It's obviously a pretty widely-used strategy, with governments from Europe to the Middle East to Asia and Australia investing in nuclear reactors, wind turbines, biofuel plantations, solar panels and so on.

The grand plan, of course, is that they will gradually supplant the coal and gas-fired powers stations, the oil-fuelled cars and the gas-heated homes. But will they?

Richard York from the University of Oregon, US, whose studies focus on the social dimensions of climate change, decided to examine this replacement issue empirically and see if it actually happens.

His conclusion is that it largely doesn't.

The paper he's published in Nature Climate Change this week used data from the World Bank and other data sources to look first of all at electricity on its own, and then at all energy.

Not every country has compiled the data; but most have, and some records date back 50 years or more.

Depending on the precise way he cut the analysis, he found that each unit of low-carbon energy coming into the economy displaces at the most about a quarter as much fossil-fuel energy - and at the least, just 1/13th.

In other words, if a government wants to replace the electricity generated by a one gigawatt (GW) coal-fired power station, it would have to supply 13GW from new nuclear or renewable installations.

As a sidebar, as we're talking about actual energy here rather than installed capacity, the implication for the scale of renewables needed with their intermittent generation is much higher.

It seems counter-intuitive. So what's going on?

"Often the misunderstanding is that demand is kind of 'out there' and exogenous, and supply is created to meet demand - but in some ways I think supply creates demand," Dr York told me.

"The rise of the giant sports utility vehicle is an example of how energy gets siphoned off when we make it too available. [And] the rise in bigger houses, in America we can them McMansions. So you add energy, it makes it more available, and leads to a lot less conservation as it trickles through the economic processes."

In other words, whatever energy is there will be used.

It's important to note that the equation for developing countries may be very different.

Here, renewables may be replacing nothing - they're often new capacity, especially in rural areas with no electricity connection to the grid, and make a meaningful contribution to development.

However, it's developed nations that are supposed to make the first cuts in fossil fuel emissions, according to what they've agreed under the UN climate convention, so it's here that any lessons should really apply.

So what is the lesson?

"There's this common view that if we just increase alternative energy development, that will naturally filter through the economy and displace fossil fuels," said Richard York.

"I think what it says is that we need actively to suppress fossil fuels if we want to remove them, [using] something like a carbon tax - and to the extent that we subtract fossil fuels, that creates the incentive to foster alternatives."

The prescription is already being followed in a number of countries that have carbon taxes or trading schemes. But what the research suggests is that governments would decarbonise faster if they paid more attention to curbing fossil fuel use and less to stimulating alternatives.

However, there's a big political price for that - and in the short term, an economic price as well.

In recessionary times, it would mean making energy more expensive. Unpopular, and damaging to attempts to rebuild from the downturn.

Nevertheless, it does appear to confirm what others have suggested before; that curbing the supply of carbon-producing fuels into the economy is ultimately the best way to curb emissions.

You can't burn what you don't have.

It's the central idea of The Economics of Ecosytems and Biodiversity (Teeb) project, which, among other things, calculated a few years back that degradation of the world's forests is costing the global economy $2-5 trillion each year, with the brunt falling on the poor who live closest to tropical forests.

At the last meeting of the UN biodiversity convention 18 months ago, governments pledged to look at including natural capital accounts in their national systems; and it's set to be a major theme of the forthcoming Rio+20 summit.

Speaking on Tuesday evening in London at a meeting organised by the Globe International group of legislators, UK MP Barry Gardiner gave a rather pithy example of how this can work.

While environment minister a few years back, he recounted, he'd signed a grant for £6m for research on fungal disease in bees.

Treasury officials had objected, arguing that "you could build a hospital for that".

However, the objections disappeared after he pointed out that the decline in the UK's bee population was costing the economy about £200m a year, with worse to follow unless the trend was arrested.

Over the years, academics have gathered countless examples from around the world of this sort of equation, from forests in the Amazon (protecting soil, purifying water), mangroves (fish nurseries, flood protection), glaciers (water regulation), peat (carbon storage, biodiversity) and many, many more.

The Stockholm Environment Institute (SEI) has come to the table this week with a weighty analysis of the oceans.

They've looked at a number of different ways in which climate change is set to impact economies through its effects on the oceans, from sea level rise to storm surges to perturbation of fish species.

Their overall conclusion is that by the end of the century, the difference between a "business-as-usual" trajectory for carbon emissions and a path of restraint that keeps the global average temperature rise below 2C is about $2 trillion per year.

As they point out, this is necessarily a simplification of the true picture facing the oceans because there are many other factors impacting them as well, including plastic pollution, acidification, hypoxia stimulated primarily by run-off from agricultural land, over-fishing and so on.

When I spoke to the project's co-editor, Kevin Noone from the Royal Swedish Academy of Sciences and Stockholm University, he said that ways of calculating the effects of all of these factors in conjunction don't yet exist.

"Frankly we weren't able to say a whole lot about the economic impacts of the interactions," he admitted.

"We were able to say something about the ecological threat of these interactions; but in terms of the economic effects, many of these factors are taken by themselves - tourism and storms and sea level rise - the economic analysis of the impacts of those are done pretty much in isolation and then they're summed up, so the economic analysis doesn't yet take into account the full interaction."

There are two subtly different reasons why various groups of people advocate natural capital accounting.

One is that by measuring the economic value of intact resources, you enable policymakers to make better decisions; that might be termed the economist's reasoning.

The other is a belief that the sums you come out with will be sufficiently high as to create an unanswerable case for protection; that's the conservationist's rationale.

In the case of Barry Gardiner's bees, the sums seem pretty conclusive.

I'm not so sure about the SEI analysis of the oceans. Two trillion dollars per year is a sum unlikely to reach the back pocket of even the most avaricious banker; but by 2100, SEI, says, it'll amount to just 0.37% of global GDP.

If the economic impacts of stopping some of the things that cause degradation is bigger, the economist is going to argue "keep on doing them".

A complicating factor is that the costs of stopping degrading activities and the costs of not stopping them are often borne by different countries.

Brazilian and UK parliamentarians at the Globe event this week emphasised that in their view, you have to have accurate natural capital accounting in order to make good economic decisions.

A hypothetical African country that is chopping down trees willy-nilly and selling the raw wood may see an economic return from the sales; but the economic losses from soil erosion, disturbance of water catchments and so on could far exceed it.

This was Mr Gardiner's illustration of a country thinking it was making a profit when actually it is making a loss, because of incomplete accounting.

The UK is, in principle at least, is in the vanguard of the new green economics, by establishing a Natural Accounts Committee that will advise Chancellor of the Exchequer George Osborne.

Other countries such as Costa Rica are arguably ahead of the UK, having implemented Payment for Ecosystem Services (PES) schemes for sectors of their economy.

As to whether this will always produce an argument for conservation, however... we will have to wait for a lot more real-world examples, I suspect, before we know.

It's largely a UK-focused argument, but many of the points being raised are cogent for the rest of the world too.

I've been told that to a certain extent it's my fault by publishing, on Monday, an article relating to a letter that four former Friends of the Earth UK directors including Tony Juniper sent to UK Prime Minister David Cameron.

Their top line was that Mr Cameron's nuclear keenness is effectively putting Britain's climate and energy policies in the hands of French companies - and, as those companies are largely owned by the French government, putting those policies under the control of Nicolas Sarkozy.

Their deeper arguments concern the economics of nuclear power, and they're more important in the long run than a bit of national stirring.

Battle was joined later in the week by a group of five self-styled "writers and thinkers" including George Monbiot, with whom many years ago, when a sound engineer, I nearly went to make a documentary on pygmies in West Africa, and who (more pertinently) was last year judged by his peers to be the most influential environment journalist in the UK.

Their principal argument is a balance of risks: climate change is more serious than the various risks associated with nuclear power, they judge, ergo the UK and many other places must forge ahead.

If the reasons why the dispute is important were not evident enough, the Organisation for Economic Co-operation and Development (OECD) conveniently spelled them out for us this week in its Environmental Outlook to 2050:

"World energy demand in 2050 will be 80% higher... and still 85% reliant on fossil fuel-based energy. This could lead to a 50% increase in greenhouse gas (GHG) emissions globally and worsening air pollution," it says.

"The atmospheric concentration of greenhouse gases could reach 685 parts per million (ppm) CO2-equivalents by 2050. As a result, global average temperature is projected to be 3-6C above pre-industrial levels by the end of the century."

Though the temperature rise figures are the most far-reaching, the number that should probably make both camps in the green battle do a bit of head-scratching is the one for energy.

What the OECD is basically saying is that all non-fossil fuel technologies are set to stay so unattractive for the next 38 years that for all the talk of costs coming down, of side-benefits such as cleaner air, of super-grids and devolved generation, humanity will still be burning coal, oil and gas for five-sixths of its energy needs.

The OECD makes clear that this fossil-fuelled future isn't immutable, and indeed puts forward a raft of options for changing it - in particular, establishing a global carbon price and slashing fossil fuel subsidies.

You can broadly translate this prescription into "having enough political will" - and the history of the last couple of decades, in a range of arenas including the G20 and the UN climate convention, shows that assuming this will materialise is a strategy likely to result in disappointment.

So if either the pro-nuke or anti-nuke greens are to see the future they both want - one powered by copious amounts of low-carbon energy - the obvious strategy is to map out a route for change that doesn't involve waiting for the Godot of political will.

At root, the trick must be to make alternatives more attractive than fossils in whatever ways will work.

Some governments are helping that process along, such as Germany's feed-in tariffs that have made such a difference to the solar photovoltaics industry.

But it may be that if low-carbon technologies can't stand on their own financial feet, they'll never get much beyond the 15% share that the OECD predicts under business as usual.

That being so, perhaps the forces of General Juniper and Marshall Monbiot could concentrate some thinking power on the key question of how their respective causes can be made appealing enough that everybody joins up willingly.

As the pro-nuclear camp in this arena is also pro-renewables and pro-efficiency, a lot of the questions are ones they share.

On efficiency - often described as a "low-hanging fruit" despite appearing pretty resistant to plucking - one enduring question is how to persuade people simply to use less.

Another is how to combat the issue that while fridges and cars and light bulbs are becoming more frugal, people are buying more of them.

A "one fridge per household" policy would be likely to prove as popular as China's "one child per family" - so how else can it be done?

On renewables, the seemingly eternal questions are cost - on just about everything bar hydro, geothermal and (increasingly) onshore wind - and intermittency.

The second is a minefield because the technical responses make a rich mix, ranging from "it's not a problem because if you have enough wind turbines they compensate for each other" to "you need a fossil fuel power station on standby for every wind farm".

The facts lie somewhere in the middle. Next to them is a big fat bin labelled "energy storage", and it's virtually empty.

And I heard an interesting comment the other week from someone connected with grid issues - that the engineers like to have a bit of wind power in the mix because wind turbines are the easiest thing by far to switch on and off.

How widely that view is shared, I don't know; but on the opinion-forming side at least there's clearly a deal of work to be done to convince people that renewables can easily provide baseload power when wind turbines demonstrably stop, the Sun demonstrably stops shining, tides demonstrably come and go and very few countries have anything in the way of a storage capacity.

On the nuclear side, the cost issues are complex partially because the timelines are so long.

But transparency there should surely be. A supposedly open market that is rigged so far in one direction is no longer open; let us be honest about these things.

And although pro-nuclear voices (industry and greens) argue, correctly, that Fukushima didn't kill anyone and that the dangers of radioactivity are often exaggerated, that doesn't stop people not wanting to live in a potential fallout zone.

It doesn't wash away the radioactive caesium nor the fear of it; nor does it put the countless billions of dollars that the Fukushima incident cost back into Japanese national coffers.

Clearly, if the idea of a 3C or 4C or even 6C world scares you, these are the kind of hard questions you have to answer about the technology of your choice.

And they are hard; if they were easy, they wouldn't be questions anymore, and green would no longer be going against green in the battle of the energy opinionosphere.

In a nutshell: does the way humanity governs itself need a series of tweaks or a complete overhaul, in order to meet the broadest ambitions of improving the lot of the planet's poorest, safeguarding nature and making the global economy more sustainable?

It's a question that one academic grouping, the Earth System Governance Project, has spent a decade researching.

The group has published many research papers along the way, and some are pretty specialised.

But this week they lay out the top-level conclusion in a short article in the journal Science.

It is that in order to "change course and steer away from critical tipping points... that might lead to rapid and irreversible change", something radical is needed.

"This requires fundamental reorientation and restructuring of national and international institutions toward more effective Earth system governance and planetary stewardship," they write.

Theirs is a seven-point plan:

Some of these are already being addressed in the Rio process, especially the first two; although their CSD proposal contains the innovative element of adjusting the weight given to each country's representation so that the G20 grouping accounts for 50% of the votes.

This might appear undemocratic; but actually it would ensure the voting reflects the size of countries' populations more accurately than it does now, though also skewing things towards the rich.

The most radical idea in procedural terms is introducing majority voting in UN fora to prevent a few recalcitrant nations from blocking the will of the vast majority.

There have been many times in the past when just one or two countries held up progress in UN processes such as the climate change convention - and the same issue is now being raised within the EU, where last week Poland on its own managed to block the setting of tougher carbon emission targets.

On the other hand, some countries' protests clearly matter more than others.

Whereas the 2007 UN climate summit in Bali hinged on whether the US would block the will of every other country on the planet - it eventually chose not to - the objections of Bolivia at the equivalent meeting in 2010 were basically ignored by everyone else, who decided in that case that a consensus could leave one nation out.

One suspects this particular reform would be tough to push through; and it isn't the only one.

As so often in environmental and sustainability circles, the plan contains no shortage of ideas on what should be done, and why, and by when.

The politics of how to make it all happen are a different matter.

In this case, how to get economic bodies to put Rio+20 notions at the centre of their decision-making, how to persuade governments to give up their right of veto, how to project the concerns of citizens through the blockage of bureaucracy - these aren't in the prescription.

And that "how?" issue is the toughest part of making a real transition.

Three billion people living on less than $2.50 a day. One billion with insufficient access to clean water; about 2.4 billion people without a decent energy source; 1.2 billion suffering from chronic hunger - all this, said UN climate convention (UNFCCC) chief Christiana Figueres at the Barbara Ward Lecture in London, is "morally unacceptable".

Despite the spectacular successes of nations such as China, Thailand, Malaysia and Brazil in raising living standards, and despite advances secured by the Millennium Development Goals (MDGs), there are many who would agree with Ms Figueres' summation.

And the reason why a climate change official would be discussing such matters?

Because climate change is one of the issues that threatens to exacerbate the situation - raising sea levels, increasing drought in drought-prone areas, reducing crop yields, and so on - a familiar list by now, I'd think, to anyone who follows these issues.

And the corollary: that however people are brought out of their various types of poverty, it mustn't be done in a way that worsens climate change or pushes any of the other planetary boundaries beyond stretching point, because that would in time cancel out the gains.

In short, it must be sustainable.

That's why Ms Figueres, self-described "daughter of a revolutionary", looked forward to this June's Rio+20 summit in Brazil as much as she looked back to last December's UNFCCC conference in South Africa.

It's now 100 days until the curtain lifts on the Rio+20 summit, so it's a good opportunity to take stock of preparations.

A few weeks back I went through the main points in the "zero draft" agreement penned for the summit; but bits of flesh have subsequently been put on the bones of that draft.

In particular, we're beginning to see an outline of what the proposed sustainable development goals (SDGs) might cover.

In a sense, these are the real meat of the summit, outlining in which ways governments hope global society will progress and develop without putting prospects for nature, and future generations of humans, at risk.

One of the discussion documents issued by the Rio+20 secretariat suggests seven areas on which its goals might focus:

These are pretty sweeping, and capable of being interpreted in varying ways. Does the last-named include financial disasters, for example, bearing in mind that resilience of the global financial system is part of the summit's mandate?

Meanwhile, Colombia and Guatemala - undoubtedly with the backing of other governments - have put forward their own proposal which outlines eight key areas, such as combating poverty, changing consumption patterns, and enhancing energy security.

To a large extent, this is a different way of cutting the same cake; the underlying issues are not going to change because you look at them through a different lens, to mix metaphors.

The goals themselves are very unlikely to be finalised at Rio. Instead, the idea is to look for agreement in principle on themes and agree a mandate to negotiate the goals over the following three years, neatly ending in 2015, the target year for most of the existing MDGs.

There are some common misconceptions about what setting goals like these is supposed to achieve.

Firstly, they're not mandatory targets such as those that emerged, for example, from the Montreal Protocol on phasing out CFCs.

It's not even certain that every government signing up will strive to meet them; there's no sanction if they choose not to.

What the targets do is allow governments and other players - businesses, civil society, academics, journalists - to monitor progress governments are making, and chivvy them to hurry up when necessary.

Just establishing ways to measure progress can be enough to facilitate it, by raising information and skill levels.

Also, comparing the rates of progress made in different countries allows people to analyse and detect factors that determine success or failure.

Of all the ideas for SDGs, a couple stick out as likely to prove particularly contentious.

One is regulation of the oceans. Even since the 1992 Rio Earth Summit, the reach of fishing fleets has extended further and deeper across the globe. Their activity on the high seas is pretty much unregulated.

A number of powerful fishing nations want to keep it this way. Others will want to block moves to restrict minerals exploitation.

The second is sustainable consumption. To some noses, the notion of changing patterns of consumption from above carries a distinct whiff of Big Brother, and is to be resisted on principle.

In London last week, Christiana Figueres was adamant that "business as usual" had to change if the poor were to eat and drink to a decent standard.

She quoted from Barbara Ward, founder of the International Institute for Environment and Development (IIED), whose work combined advocating environmental protection and campaigning for overseas development aid, and in whose honour the annual lecture is named:

"This visionary woman once said: 'We live in an epoch in which the solid ground of our preconceived ideas shakes daily under our certain feet'. Already in the 1970s, Barbara knew that 'business-as-usual' no longer represented 'solid ground'."

However, the politics of going beyond "business as usual" are still formidable.

Even as Ms Figueres was speaking in London, EU ministers were wrangling over the bloc's goals on climate change and renewable energy in Brussels - a meeting that ended without agreement on strengthening carbon-cutting ambition, essentially because just one of the 27 nations there, Poland, did not want to.

When international political systems are based on consensus, those who hold a position against the prevailing tide are given power out of all proportion to the constituencies they represent - and that's even more true in the UN than in the EU.

And from the corporate sector, seven companies involved in aviation have written to European governments complaining about the recent inclusion of plane emissions in the EU Emission Trading Scheme (ETS).

They include British Airways, whose website carries the claim: "As part of our commitment to being environmental responsible [sic] we have been a long-standing supporter of emissions trading.

"This sits at the heart of our climate change policy as the most environmentally effective and economically efficient mechanism for addressing aviation's CO2 emissions."

All for carbon cutting in principle, then - but not if it might affect business as usual.

That, in a nutshell, is the challenge Ms Figueres has highlighted - and the challenge that will face those world leaders who have decided to go to Rio de Janeiro in 100 days' time.

For those of you who don't speak UN climate convention-ese, what I mean is that governments have taken their first tentative steps in the process towards negotiating a new global climate deal.

The agreement to start talks now and reach such an deal by 2015 was the major decision of December's UN climate convention (UNFCCC) meeting in Durban, South Africa.

Why it's called the Durban "Platform" rather than "process" or "mandate" is beyond me, but Durban Platform it is, and it's a phrase that could become as familiar as "Kyoto Protocol" in the next few years.

The first thing that governments committed themselves to was sending in their thoughts on how "ambition" could be increased - in other words, how carbon emissions can be tackled more enthusiastically than they are at the minute.

Their deadline was last Wednesday; and when I looked on the UNFCCC website then, things didn't look too promising, with Pakistan's the only submission posted, and that focussing mainly on forestry.

Since then, quite a few more have gone up - and reading through, you get a sense of where the battles are going to be fought.

The submissions of the blocs of countries most vulnerable to climate change are probably the least surprising.

Gambia, on behalf of the Least Developed Countries bloc (LDCs), points out that developed nations (Annex 1 countries, in UN-speak) have simply not committed to the carbon cuts that science indicates they should, if they are serious about constraining the rise in average global temperature since 1990 below either 1.5C or 2C - targets that different groups of countries espouse.

"The current pledges proposed by Annex I countries in aggregate add up to 13-18% [by 2020] below 1990," the submission reads.

"Compared to the 25-40% range estimated by the Intergovernmental Panel on Climate Change (IPCC) to be required, this aggregate reduction is insufficient to achieve the 1.5C and 2C climate goals..."

In the face of projections of sea level rise, water shortages and various other impacts across these nations, they urge swift action.

"If emissions are not reduced in line with scientific requirements in the near‐term, it would be extraordinarily difficult or impossible to compensate later on," says Nauru, on behalf of the Alliance of Small Island States (Aosis).

"In other words, the chance to achieve the below 2C and well below 1.5C goals may be irrevocably lost even before 2020."

Delay creates two types of problem, says Aosis.

One is physical, in that tipping points such as release of methane trapped in Arctic ice may be irrevocably triggered. The other is that finance will be committed to high-carbon technologies that will keep emitting CO2 for decades, rather than low-carbon ones.

While these two blocs are demanding urgency, with action kicking in well before 2020 from as many countries as possible, that's not the view of their developing world partner India.

In Durban, India stood out longest and loudest against moves to kick-start a new process, on the grounds that only Annex 1 countries should as of now be committing to anything.

While it's happy to see those nations get started on carbon cutting before 2020, it doesn't believe that anyone else should have to as a result of the Durban agreement.

"India is of the view that the work plan for enhancing mitigation ambition of Parties relates to the post-2020 period," its submission reads.

What follows is a bit technical, but essentially the argument is that the scientific evidence for having any countries set emission reduction targets comes from the IPCC's last report, known as AR4, which came out in 2007.

And as those targets refer to Annex 1 countries, India argues, they should get on with it; but not the rest.

The next IPCC report, AR5, comes out in 2013-4. And the UNFCCC is due to have its own review of the mismatch between science and policy in 2013-15.

"Considering the fact that the results of the peer-reviewed comprehensive scientific assessments under AR5 and the work of 2013-15 review will be available only in the time frame of 2015... the only available time frame for making scientific assessment of the mitigation efforts by all Parties is the post-2020 period," India argues.

India's per capita emissions and income are still relatively low, and will remain so until beyond 2020 at current rates of growth.

But the validity of its argument will be questioned on the basis that some non-Annex 1 countries, such as the Gulf states, already have higher per capita emissions than some in Annex 1.

And the biggest elephant in that particular room is the great leap forward in China's per capita emissions that could take it past the EU average well before 2020.

The EU's submission is the one that really breaks new ground, by demanding that this issue be put on the table and formally discussed.

Developing country submissions (including those from India, Bolivia and Ecuador) all use the familiar form of words enshrined in the UNFCCC - that countries should take action on the basis of "common but differentiated responsibilities and respective capabilities".

Where the EU breaks new ground is by pointing out formally that these things change.

"The new agreement to be negotiated... should include mitigation commitments for all Parties and in particular all major economies taking into account that responsibilities and capabilities are differentiated but evolve over time and that the agreement should reflect those evolving realities by including a spectrum of commitments in a dynamic way," it says.

In other words - if you get rich fast and your emissions rise accordingly, you should expect to shoulder a bigger share of the global emission-cutting burden.

The EU also backs the Aosis arguments for swift action.

"The scale of the global mitigation challenge beyond 2020 is strongly dependent on successful pre-2020 mitigation; the feasible emission pathways and future mitigation costs beyond 2020 depend to a large extent on the ability to transform investment patterns within the next few years."

The EU argues that a number of initiatives are in train outside the UNFCCC that could and should play a major role in the next few years:

The remaining key submission posted on the UNFCCC site at the time of writing comes from the US.

It finds some common ground with the EU in advocating an end to fossil fuel subsidies, swift action on aviation and shipping emissions, and mobilising investment in clean technologies.

However, on the subject of whether governments' existing 2020 targets should be strengthened, there's a strong hint of a "no" in the form of words that its endlessly inventive lawyers have crafted:

"Although the work plan should seek to encourage all Parties to enhance their mitigation efforts to the greatest extent possible, the work plan should also respect the integrity of Parties' nationally derived targets and actions and limitations inherent in taking economically sound mitigation policies at a national level."

As the US is the country most responsible for the gap between the 25-40% ambition recommended by the IPCC and the 13-18% level noted by Aosis, it's hard to see quite how that gap can be bridged without the US being willing and able to do a bit of swift enhancing.

The first official talks on the Durban Platform happen in May. But the negotiating positions of some of the major players - no China yet, or Saudi Arabia or Russia or Japan - seem pretty clear and, for the most part, pretty familiar.

If only Homo erectus had invented the weather station and distributed its invention evenly as the species expanded its footprint across Africa and then the world...

The shortness of the satellite record, going back only to 1979 or thereabouts, is a particular gripe.

One of the most fascinating areas of research that's emerged in the last couple of decades is historical climatology - trying to deduce evidence on past climates through written records.

Whereas palaeoclimatology measures tree-rings and stalactites and deposition patterns in sediment, historical climatologists scour the log books of ships, parish ledgers of grape harvests and the diaries of amateur naturalists for clues.

Perhaps the most fertile ground of all lies in ancient civilisations that established the equivalent of modern civil services early on - where records were kept for year after year, recorded as part of the dynasty's foundation.

Chinese records, for example, kept by court mandarins have yielded data on aspects of weather and climate including rainfall, temperature, thunderstorms and typhoons.

In the magazine Weather this month there's a fascinating paper doing the same thing with records from what is now Iraq going back over 1,000 years, using documents stored in Madrid and in Baghdad itself.

Founded in AD762, Baghdad quickly grew in size and importance as capital of the Abbasid Caliphate.

The Caliph's record-keepers didn't specifically write about weather and climate.

But Fernando Dominguez-Castro from the University of Extremadura, Spain, and his team of scholars have been able to extract a good deal through passing references in the writings of al-Ya'qubi, author of a major treatise on the region in 891, and his successors.

Back then, water was plentiful, judging by the network of canals constructed in the region.

The climate appears to have pleased al-Ya'qubi, with heat in summer, cold in winter, and mild in between.

It's hard to judge what "heat" and "cold" mean in this context, with nothing against which to measure them. But we get a better idea when he tells us that in summer, people spent most of the day in the coolness of rooms dug below ground-level, but their nights on open roofs under the stars.

And having established these habits, we get a better idea of the transformation wrought in AD920, when the city was caught in a snap so unseasonably cold that people took their blankets indoors in the height of summer.

Dr Dominguez-Castro calculates the temperature may have been about 9C below normal that month - related, he speculates, to a major volcanic eruption.

The records written by al-Ya'qubi and his successors also yield information on the frequency of droughts, floods, rainfall, hail, winds, hot and cold spells and locust swarms.

Snow was reported regularly in winters between 832 and 998. In 909, one writer records: "There were four fingers of snow on the ground, and the cold was intense. Water, vinegar, eggs and unguents froze."

Things sound even more extreme in 926, when "sherbet and rose-water froze, as well as vinegar.

"The scholar known as Abu Zakaria sat in the middle of the Tigris, on the ice, and gave lessons of the Prophetical Tradition."

Later scholars recorded no snow.

So here we have evidence of a change of climate, which appears to have occurred at the same time as some parts of the world were entering the Medieval Warm Period (MWP).

So this would support the idea that Baghdad, and by extension the rest of the Mesopotamian region, experienced the MWP as well.

There are clearly limits to historical climatology. A minority of ancient cultures kept records, and some texts in extinct languages (such as Etruscan) we cannot decipher.

While concrete events such as typhoons and snowstorms are faithfully recorded, less remarkable events are not, and there's little idea of gradual trends.

Nevertheless, for some parts of the world these records are among the best we have; and their use is likely to increase, through projects such as the German-funded Historical Climatology of the Middle East based on Arabic Sources back to AD800.

As Dr Dominguez-Castro told me: "A lot of Arabic sources remain unexploited with climatic objectives, with information of an epoch and places few studied until today." By studying more records, he says, it might become possible to discern slow trends as well as quick flips.

The field of inquiry also provides fascinating glimpses into people's lives during a time when weather was a bigger determining factor in their lives than it is today, and into the ways they found to adapt.

Many thanks for all your messages - nice to know one's thoughts are in such demand!

So what's happened since last week's post, flagging up and analysing the contents of documents obtained through subterfuge from the leading US climate sceptic lobby group?

First, we saw a request from the institute that all media organisations who'd covered the story should take their articles down and issue retractions, with a vague threat of legal action.

As far as I can see, few complied - and why would they?

As the old saying goes, "news is something that someone somewhere doesn't want you to know" - and here was information about a significant player in climate politics that it certainly didn't want you to have.

In saying one of the documents was a fake, the institute also signified that the rest were genuine.

Then on Tuesday, the perpetrator came forward and 'fessed up. Scientist Peter Gleick, head of the Pacific Institute and a moderately well-known commentator on such matters, spilled the beans in the Huffington Post and proffered an apology.

"In a serious lapse of my own and professional judgment and ethics, I solicited and received additional materials directly from the Heartland Institute under someone else's name," he wrote.

"My judgment was blinded by my frustration with the ongoing efforts - often anonymous, well-funded, and coordinated - to attack climate science and scientists and prevent this debate, and by the lack of transparency of the organizations involved."

Part of the lack of transparency he raised concerns funding.

The documents told us the identity of many Heartland donors, but not the identity of the "Anonymous Donor" who has given the organisation about $8m in the last four years, by far the major share of its finance for climate work.

By co-incidence, the UK's Information Rights Tribunal, which adjudicates on Freedom of Information-type issues, chose the same day to issue its ruling that the Charity Commission does not have to reveal who donated the initial £50,000 to set up the Global Warming Policy Foundation (GWPF), the leading UK lobby group.

In her judgement, Judge Alison McKenna said the GWPF wasn't influential enough for disclosure to be merited.

So where does all of this leave us?

I am very wary of drawing parallels between the so-called "ClimateGate" issue of 2009 and the so-called "DenierGate" issue of the Heartland Institute, because they are very different.

But one thing they do have in common is that each is really a combination of two stories: who lifted the documents, and what the documents tell us.

And in both, it's necessary to analyse the strands separately.

With the Heartland case, we knew last week that someone had obtained the documents by the back door - "stolen", to use the institute's word.

Now, we know who; and that's as far as it goes.

Peter Gleick's admission may tell us something about Peter Gleick. And various commentators have piled in, notably the New York Times' Andy Revkin who says the issue "leaves his reputation in ruins".

But it doesn't tell us anything about the Heartland Institute; that story lies in the documents themselves.

Let me briefly deal with a couple of the points you've been raising in your messages.

Firstly, what's wrong with the Heartland Institute preparing curriculum material for use in schools, you've asked. "Green groups do it all the time," is the allegation.

I don't know how things are in the US; but in the UK, I'm told, that certainly isn't the case. Science teachers I know are very well hooked into the web, where authoritative information on climate change isn't exactly hard to find.

As a parent and a citizen, if teachers use non-standard curriculum material, the main thing I would be worried about is accuracy.

The examples given in the Heartland proposal are not encouraging in this regard.

The proposed modules would, for example, state that "whether humans are changing the climate is a major scientific controversy" and that "natural emissions [of CO2] are 20 times higher than human emissions".

The first is just wrong. It may be a public debate; but within science, the question is how much, not whether.

In the second case, natural absorption is not mentioned and it's the difference between the two - net emissions - that is the crucial fact.

Al Gore was called out (including here on the BBC) on inconveniently extending the truth in his movie, and I hope environmental groups would be too if they did the same; so Heartland and its supporters ought to expect to be called on this as well.

The second issue I've been asked about is whether writing about the Heartland documents was ethical journalism.

This is an area with lots of shades of grey. But one of the essential questions to ask is whether revealing and discussing this kind of information is in the public interest.

Perhaps the best recent UK example is the Daily Telegraph's long-running series of articles revealing serial abuses of the expenses system by MPs.

The material was certainly lifted from the owners without their permission, and bought by the newspaper group.

But I don't know of anyone who argues it was unethical; revealing the information was clearly in the public interest, it changed practices in Parliament, and eventually resulted in prosecutions of people who'd broken the rules.

Never again will an MP try to charge the public purse for digging a moat or building a house for his ducks.

Is revealing the funding and tactics of influential groups engaged on a policy issue such as climate change not also in the public interest?

Some scientists argue it's so much in the public interest that a change of rules is in order.

One example is the open letter released on Monday by the Climate and Health Council asking that climate sceptic lobby groups reveal all their funding.

"We view the systematic sowing of unjustified doubt about mainstream international climate science as confusing at best, and inhumane at worst," they write.

It's a difficult request. Firstly, how do you define a "climate sceptic" group? Secondly, we're dealing with multiple countries, hence multiple sets of rules.

And most fundamentally, arguing against legislation of any kind is perfectly legitimate in open societies.

Nevertheless, the rationale behind the argument is clear. Heartland acknowledges it ramps its climate work up and down depending on how much money it receives from a single donor - but we have no idea who he is, beyond his gender.

GWPF and other organisations may have similar donor relationships - we don't know, because generally, they won't tell us.

That's one reason why some commentators from the environmental community are hoping Heartland does begin a legal case, because in US law the pre-trial process of discovery means the plaintiff would probably have to release lots of other documents that it currently keeps private - including, potentially, the identity of Anonymous Donor.

Perhaps, though, the most revealing documents in this whole affair do not lie in the tranche obtained by Dr Gleick.

One is the email exchange Heartland chief Joe Bast had with Gary Wamsley, a 71-year-old war veteran who took exception to institute's tactics. Follow-up pieces on the same site are also interesting.

The second is the piece Mr Bast posted on his own site lambasting a New York Times article on the leaked documents.

It's a must read.

At the centre stands the EU, cast, in this guise, as climate champion - determined to take a small step towards charging airlines for the full environmental costs of flying, and to tax highly-polluting forms of fossil fuels.

Attacking the EU from every side is a large number of countries with serious clout.

At a two-day meeting in Moscow, 26 countries opposed to the EU putting aviation inside its Emission Trading Scheme (ETS) are discussing a response, ranging from a formal protest through the Chicago Convention to unspecified "retaliatory measures".

There's even talk of a full-scale trade war, even though (as I've discussed before) the sums that industry might lose are trivial.

As soon as that ends on Wednesday night, the focus will shift to Thursday's European Commission meeting, where officials will debate a proposal to update the Fuel Quality Directive (FQD) in a way that would penalise fuels such as oils made from coal and from tar sand deposits on the grounds that their production is highly carbon-intensive.

Once again, a trade dispute looms, with Canada threatening action, possibly through the World Trade Organization (WTO), if tar sand oil is penalised.

Both issues carry a strong whiff of testosterone, with the hard men of business determined that their governments should not yield to green demands, and Europe determined to retain the climate cojones it found at last year's UN meeting in South Africa, having mislaid them two years previously in Copenhagen.

But below the posturing is something rather fundamental; and the importance of the week's events should not be underestimated.

As became clear at the South Africa meeting, a majority of governments want action on climate change and want it pretty quickly.

But because of the way international organisations such as the UN climate convention work, a small number of governments can block consensus very effectively.

China, India Russia, the US, and Canada found themselves (largely through reasons of expediency) in the laggards' room in Durban - and there's common ground between them again as they survey the EU positions.

On the aviation side, the International Civil Aviation Organization (ICAO) has been discussing a possible global agreement on restricting aviation emissions for at least 14 years, without implementing one.

So what we're seeing here is one bloc - the EU - taking its own steps outside the UN organisation to reduce not only its own emissions, but those of other countries.

If the EU is successful on either of these issues, it opens the door to other measures.

One idea that's been batted around for years is some kind of border adjustment.

So country A levies charges on emissions from companies making a certain type of goods.

Country B doesn't have any such charges. So when Country A imports that type of goods from Country B, it imposes a tariff to compensate.

You can see immediately why it's controversial; not least because if such measures came into use for climate change, might countries also try to impose them for other reasons? How far would it go before it became protectionism?

That's why all kinds of observers from environment groups and business lobbies will be watching this week's events like hawks.

The tar sands issue, where a vote is due within a European Commission technical committee, will probably be kicked upstairs to the bloc's main fora, and could rumble on for many more months.

But the aviation issue is much more mature - it's already EU law - and we may gain a better understanding in the next few days of how serious the EU's opponents are, and indeed how serious the EU is.

With the bloc struggling financially and even asking China for assistance in getting through the eurozone crisis, Brussels does not have the best negotiating position in history.

Russia, host of the aviation meeting, supplies the EU with much of its gas.

So the levers are there, if opponents want to use them.

Observers who put a lot of store by the projections of climate science will be vehemently hoping it doesn't become anything like a trade war.

One indication that it might not is that newspapers in India and China, which until recently parroted the lines of their governments, have started to question it.

A comment article in the China Daily this week said Chinese airlines might not lose anything like the amounts they're bandying around - but even if they do, "It is unwise to launch a full-scale trade war against the EU merely for the sake of the interests of China's aviation industry".

Even stronger was The Hindu Business Line, which argues that "The airline and shipping industries have long had an easier ride than many sectors when it comes to tackling climate change.

"The EU proposal may not be a perfect solution, but is an important step. Hiding behind the arguments of unilateralism and a trade war ignore the realities and is something India shouldn't be a part of."

As the article notes, there is a more constructive scenario on the horizon; that ICAO now gets its act together and comes up with a plan on which every country can agree - in which case, the EU could suspend its unilateral move.

And there's also research around showing that contrary to their protestations, airlines could actually make money from their involvement in the EU scheme.

But the stakes are bigger than a few dollars on a flight or a barrel of tar sands oil; so we may not be done with acrimony for a while.

Bangladesh, Canada, Mexico, Sweden and Ghana are signed up, and the UN Environment Programme (Unep) is going to co-ordinate the venture.

Precisely how it's going to work is unclear.

But based on existing experiences around the world and on the priorities of some of the nations involved, measures are likely to include changing farming methods to reduce methane emissions from rice paddy, investing in efficient and clean cooking stoves for Africa and South Asia, and upgrading landfill sites and wastewater treatment facilities to capture methane.

Methane is a more potent warming gas than carbon dioxide, molecule for molecule; but its lifetime in the atmosphere is in the order of a few decades, rather than centuries.

Black carbon - a component of soot - increases the Earth's absorption of solar energy.

Academic backing for the idea of tackling these substances urgently has come in a number of reports, but two particularly spring to mind.

Last year, Unep released a detailed analysis concluding that "a package of 16 measures could, if fully implemented across the globe, save close to 2.5 million lives a year; avoid crop losses amounting to 32 million tonnes annually and deliver near-term climate protection of about half a degree C by 2040".

(The life-saving aspect derives mainly from the reduction in air pollution achieved by cleaning up cooking stoves and urban transport.)

The other report was a paper in Science journal last month from a group of mainly US academics led by Drew Shindell, which reached broadly similar conclusions - and said these curbs would be affordable.

Still, the new initiative, the Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants, hasn't been greeted with universal warmth; and there are two inter-related reasons why.

The first is that according to the science, tackling short-lived climate pollutants doesn't prevent global warming - it just delays it.

The main graph in the Shindell Science paper explains this clearly.

They conclude that implementing all the recommended measures for methane and black carbon but doing nothing about carbon dioxide delays exceeding the oft-touted 2C threshold for temperature rise - but it still gets exceeded in the end.

By contrast, tackling CO2 and not doing anything about the short-lived substances sees more warming in the next few decades - but beyond about 2060, it's more effective than tackling the short-lived agents.

And it's worth emphasising that the CO2 reduction pathway that the paper used - an International Energy Agency scenario that would stabilise greenhouse gas concentrations at the equivalent of 450 parts per million of CO2 (450ppm CO2e) - is regarded by many as too lax by far.

The essential takeaway sentence from the entire paper on the relationship between tackling CO2 and tackling the short-lived agents must be this: "Implementing both substantially reduces the risks of crossing the 2°C threshold".

And the essential word in that sentence must be "both".

The Oxford University climate scientist Myles Allen is far more pithy.

"Given that we don't have any prospect of a credible plan to reduce CO2 emissions, the suggestion that immediate cuts in methane and black carbon will reduce the risk of dangerous long-term climate change is pure fantasy," he comments.

And this leads me to the second reason why the new initiative isn't being welcomed with completely open arms; because it could produce the impression that enough is being done.

The US has history here, having established the Asia-Pacific Partnership on Clean Development and Climate (by some spooky parallel, also a six-nation bloc) and later the Major Economies Forum.

The publicity at the time of their formation said they weren't designed to replace the UN climate convention process but to complement it.

The reality was rather different, with elements of the controversial 2009 Copenhagen Accord taken straight from the MEF blueprint rather than UN negotiating text, and a number of important nations finding it was the way they preferred to do business.

Now the line has surfaced again, with US Secretary of State Hillary Clinton declaring the new coalition will "complement but not supplant" the main international efforts to curb emissions.

On a pragmatic basis, some of the measures on black carbon and methane are doable, affordable and bring real health and development benefits as well, particularly on clean cooking stoves.

But emphasising short-term warmers in the absence of meaningful action on CO2, to some observers, smacks of short-term politics and an unwillingness to get to grips with the main issue.

While Europe was asleep, someone mailed a bunch of internal Heartland Institute documents to a number of bloggers including desmogblog and ThinkProgress - these two and others have since posted the documents online.