UN Report Warns Climate Warming Outlook Worsens as US Retreats from Paris Agreement

The world is on course for greater global warming than projected a year ago, with the United States’ withdrawal from the Paris climate agreement contributing to the worsening outlook, according to a new United Nations report.

The United Nations Environment Programme (UNEP) said in its latest climate assessment, released on Wednesday, that global temperatures could rise by 2.6 degrees Celsius above pre-industrial levels by 2100 if countries fulfil their existing climate commitments. This is 4.7 degrees Fahrenheit above pre-industrial temperatures and remains well above the limits set by the 2015 Paris Agreement.

The estimate is slightly worse than last year’s projections, partly because of the formal withdrawal of the United States from the agreement and revised calculations of historical emissions.

The report also identified the US as a major contributor to rising global emissions in 2025. Its carbon emissions increased by 133 million tonnes of carbon dioxide equivalent, driven by higher electricity demand and a rebound in coal-fired power generation.

Of the 189 million tonnes of additional emissions recorded among countries whose emissions increased last year, around 70% came from the United States, the report said. Other major economies among the world’s top 20 either reduced their emissions or slowed their growth.

The report warned that global temperatures would reach 2.8 degrees Celsius above pre-industrial levels by 2100 if countries continue on their current course without implementing their climate pledges.

Both projections exceed the Paris Agreement’s goal of keeping warming well below 2 degrees Celsius, while pursuing efforts to limit it to 1.5 degrees. Global temperatures have already risen by approximately 1.4 degrees Celsius above pre-industrial levels.

UN officials have acknowledged that limiting warming to 1.5 degrees is no longer considered achievable under current projections. Attention has shifted towards limiting the increase to around 1.8 degrees Celsius, followed by efforts to remove sufficient carbon dioxide from the atmosphere to bring temperatures back down.

UN Secretary-General António Guterres said the world was falling dangerously short of its climate goals but still had the tools to change course.

UNEP Executive Director Inger Andersen said global emissions would need to fall by 18% by 2030 and 69% by 2040 to bring warming back towards a manageable level.

Anne Olhoff, director of the UNEP Copenhagen Climate Center and lead author of the report, estimated that the US policy shift could add approximately 0.1 degrees Celsius to global temperatures by the end of the century.

Climate scientists warned that even a small increase could have serious consequences, including more intense heatwaves, destructive floods, crop failures and damage to vulnerable ecosystems. Bill Hare, chief executive of Climate Analytics, said the additional warming could expose another 140 million people to dangerously hot conditions.

University of Pennsylvania climate scientist Michael Mann estimated that the consequences could also cost the global economy about $1.2 trillion.

Researchers warned that the impact could extend beyond US emissions, as weaker climate action by Washington could discourage other countries from maintaining their own commitments. They said faster emissions reductions and stronger international cooperation would be essential to limit the damage from rising temperatures.