Lula says "COP30 will be the COP of truth," as he urges participating countries not to "abandon the objectives of the Paris Agreement".

He says the planet is now moving to be 2.5C hotter by the year 2100.

"Human losses and material losses would be drastic," he says.

He says there's been "mutual mistrust and selfish interests prevailing over the common good."

But now is the moment to "take it seriously," Lula says, adding that the world needs to "decide if we will have the courage and necessary determination to transform things."

Image source, Reuters

Brazilian President Luiz Inácio Lula da Silva begins his speech by thanking those in attendance, in particular those part of the Brazilian delegation.

"For the first time in history a climate COP will take place in the heart of the Amazon," Lula says, adding that there's "no higher symbol of the environmental cause than the Amazon Rainforest".

He goes on to describe the wealth of biodiversity in the region, which is "the most diverse biome in the Earth".

"Here live millions of people and hundreds of indigenous people, where their lives are faced with a false dilemma between prosperity and preservation."

Mark Poynting
Climate reporter

As we've just reported, the UN says it's now "virtually impossible" to avoid overshooting the 1.5C warming target - which the UN chief says is a "red line for humanity".

But what is this target and why is it important?

Ten years ago, world leaders pledged to limit global temperature rises to "well below" 2C above "pre-industrial" levels - the late 1800s - and to try to keep warming to 1.5C.

A very large body of scientific evidence shows that warming of 2C or more would bring far greater impacts.

Long-term warming - often measured over a 20-year period - still stands below 1.5C.

But the target is getting perilously close and humanity continues to emit record amounts of planet-warming gases.

That has forced the UN to concede that the target will be breached.

It is still hopeful that temperatures can be brought back down to 1.5C by the end of the century - but that won't be easy.

Read more in our simple guide to climate change.

Last year, emissions reached another record high, Guterres says, citing the World Meteorological Organization's newly published stats which confirm emissions continue to rise.

He says that the "1.5C degrees limit is a red line for humanity".

If we act now at speed and scale, he vows, "we can make the overshoot as small, as short, and as safe as possible, and bring temperatures back below 1.5C before the end of the century".

"The United Nations will not give up," he adds.

Next up is Brazilian President Luiz Inácio Lula da Silva.

Image source, Reuters

The UN's Secretary-General António Guterres says the world has "failed to ensure we remain below 1.5 degrees."

He says a "paradigm shift" is needed to drive temperatures down - and even a temporary overshoot will have huge consequences.

It will "expose billions to unlivable conditions," he says, leading to more "anger, displacement and loss" for those least responsible for climate change.

"This is moral failure and deadly negligence," he says, and it "still falls short of what is needed."

Image source, PA Media

Prince William is on the fourth day of a five-day visit to Brazil - his first trip to the country.

While in Brazil, the Prince of Wales has followed in his mother's footsteps with a visit to the Christ the Redeemer statue in Rio de Janeiro.

He is primarily in Brazil for two reasons, both environmental: to present the Earthshot Prize, and to speak at COP.

The Earthshot Prize is an annual awards ceremony which aims to celebrate and support people working to provide innovative solutions to environmental issues, including climate change.

The event took place last night in Rio de Janeiro and the prince described winners as an "inspiration that gives us courage".

Matt McGrath
Environment correspondent in Belém

It is now “virtually impossible" to keep to the international target of limiting global warming of 1.5C, the chief of the UN's World Meteorological Organization says.

Celeste Saulo tells world leaders in Brazil it's essential to bring temperatures back down to the 1.5C target by the end of the century.

For context, world leaders pledged a decade ago to try to limit global warming to 1.5C above pre-industrial levels in the Paris climate agreement.

Saulo says: "The record increase in greenhouse gas levels means that it will be virtually impossible to limit global warming to 1.5C in the next few years without temporarily overshooting the Paris Agreement target."

“We can’t rewrite the laws of physics, but we can rewrite our path," she adds.

Justin Rowlatt
Climate editor in Belém

Faith in the UN climate process is faltering.

Only a few dozen heads of state are expected at today’s summit.

The leaders of China, India, and the United States - responsible for nearly half of global emissions - will not attend.

The US is withdrawing from the Paris Agreement, and the UN admits that recent national pledges to cut emissions fall short. Secretary-General António Guterres has conceded that the 1.5C target set in Paris will soon be breached.

Still, there are signs of progress: renewable energy technologies are spreading far faster than expected, and the global rise in CO2 (carbon dioxide) emissions has almost plateaued.

Yet, these gains owe more to market forces than to the Paris Agreement, which is why questions are being raised about the value of these huge gatherings.

Matt McGrath
Environment correspondent in Belém

A new report released here in Belém today highlights, once again, the reality of climate change.

The World Meteorological Organization has just issued a State of the Climate in 2025 update.

It shows this year is likely to be the second or third warmest on record, with average temperatures between January and August 1.42C above "pre-industrial" levels of the late 1800s.

Ten years ago world leaders pledged to try to limit global warming to 1.5C above pre-industrial levels.

Esme Stallard
Climate reporter in Belém, Brazil

Image source, Mauro Pimentel/AFP/Getty Images

As you make your way to the COP venue, the common noises of city traffic are interspersed with tropical bird calls reminding you that this year’s climate summit is no ordinary one.

The city of Belém really is nestled in the Amazon rainforest, with its towering trees pushing right up against the city boundaries.

Although the surroundings are beautiful the venue is no different from any giant conference centre. It is normal on the day things kick off for there to be last minute preparations, but it seems the Brazilian team are even further behind than is normal.

Hundreds of construction workers are busy running around the venue still building the internal walls and planting trees in an effort to bring some greenery inside.

The Brazilian’s have struggled to pull this event off, with challenges in finding enough accommodation - with some delegates telling me they are staying in shipping containers.

Let’s hope this isn’t an omen for how the negotiations will go here.

Mark Poynting
Climate reporter

Image source, Getty Images

Unusually, world leaders are meeting before the official start of the COP conference on Monday.

That’s partly for logistical reasons, such as easing pressure on hotels.

But organisers also hope that it will generate positive momentum ahead of the conference.

That’s seen as particularly important in a year in which climate action has come under attack from the Trump administration and others.

So expect leaders to reiterate their commitment to tackling climate change and to argue the economic case for moving to cleaner energy.

It’s thought that leaders might try to strike some early agreements before giving way to their delegations to thrash out the nitty-gritty of formal negotiations next week.

That is expected to include launching a fund to protect tropical forests, known as the “Tropical Forests Forever Facility”.

Elliot Burrin
Live reporter

World leaders are gathering in Belém, Brazil, for this year's COP30.

The annual climate conference doesn't officially begin until Monday, but around 60 world leaders are attending today and tomorrow for talks hosted by Brazilian President Luiz Inácio Lula da Silva.

UK Prime Minister Keir Starmer and Prince William will also be speaking a little later on.

Stay with us for the latest updates from the conference in the heart of the Amazon.