President Trump was under attack on Thursday as world leaders lined up to criticise his stance on climate change ahead of the global COP30 summit.

The US leader, who is absent from the gathering in the Amazonian city of Belém, was called a liar for his rejection of climate science and being against humankind for his rollback of key climate policies.

UK Prime Minister Sir Keir Starmer acknowledged the waning political consensus on the issue. He stated climate change was once a unity issue but today however, sadly that consensus is gone.

Over the next two weeks, countries will try and negotiate a new deal on climate change, focusing particularly on channelling more money to forest protection.

Many leaders from the world's largest nations – India, Russia, US and China - are notably absent from this year's summit.

While President Trump isn't attending this meeting in Belém, his views on climate change are certainly on the minds of many of the other leaders present. In September, during a speech at the UN, the US president described climate change as the greatest con job ever perpetrated on the world.

Without naming the US leader, President Luiz Inácio Lula da Silva of Brazil warned of extremist forces that fabricate fake news and are condemning future generations to life on a planet altered forever by global warming.

The leaders of Chile and Colombia went further, labeling the US president a liar and urging other countries to disregard US efforts to walk back climate action.

However, while Trump-bashing appeared popular with the audience, achieving consensus on actionable climate measures remains challenging.

Only a few dozen leaders have turned up in Belém, and a majority of countries have failed to submit new plans to cut carbon emissions, which are the root cause of rising temperatures.

Despite UK Prime Minister Sir Keir Starmer acknowledging that global political support for the climate movement is waning, he stated to those present: My message is that the UK is all in.

However, in a blow to the Brazilian hosts, the UK announced its choice to opt out of its flagship $125bn (£95bn) fund to support the world's rainforests, a project that was under UK leadership when it was launched during the 2021 COP summit in Glasgow.

President Lula expressed hope to raise $25bn for the Tropical Forests Forever Facility, appealing to developed nations to support conservation efforts crucial for climate stability – ecosystems that cover only 6% of the planet's land but contain massive quantities of CO2.

The UK’s withdrawal has frustrated Brazilian officials, who had expected strong UK participation in the initiative.

Amid these discussions, Prince William encouraged leaders to foster collaboration and immediate action, emphasizing the high stakes for future generations.

As the COP30 summit progresses, world leaders must navigate complex challenges related to climate finance and address the pressing impacts of climate change, exemplified by recent extreme weather events such as Hurricane Melissa, significantly intensified by climate change.