UN Report Says Passing the 1.5C Warming Limit Is Now Unavoidable

The world can no longer keep global warming within 1.5 degrees Celsius of preindustrial levels without at least temporarily overshooting that mark, the United Nations Environment Programme said on Wednesday in its annual assessment of the gap between countries’ climate pledges and what science says is needed.

The report, titled ‘The point of return,’ concludes that after decades of insufficient action, a breach of the 1.5C goal set in the Paris Agreement is effectively inevitable. Limiting warming to 1.5C with little or no overshoot is no longer feasible, the authors wrote, so the aim must shift to minimizing how high temperatures climb above it and how long they stay there, Carbon Brief reported.

Under policies now in place, the report projects warming of about 2.8C by 2100, with a 10 percent chance of exceeding 3.4C. If countries fully carry out their current national pledges, warming would be about 2.6C. Only in the most optimistic case, in which countries also meet their long-term net-zero targets, would warming be held to about 2.1C. The central estimates for the pledge scenarios are 0.2C to 0.3C higher than in last year’s report, largely because of the United States’ withdrawal from the Paris Agreement and revisions to historical emissions data, according to Carbon Brief.

To bring temperatures back down to 1.5C by the end of the century after the smallest possible overshoot, global emissions would need to fall 18 percent by 2030, 45 percent by 2035 and 69 percent by 2040 compared with 2025 levels, with carbon dioxide emissions reaching net zero around 2050. Under that pathway, warming would peak around 1.7C to 1.8C around midcentury. Current pledges, even if fully met, would cut emissions only 5 to 8 percent by 2030 and 11 to 15 percent by 2035.

Global greenhouse gas emissions totaled about 58.4 billion metric tons of carbon dioxide equivalent in 2025, roughly flat compared with 2024, though the report called the figures provisional. Emissions growth has slowed from an average of 1.7 percent a year between 1990 and 2015 to about 0.8 percent a year since 2016. Among the six largest emitters, the United States was the only one to post a notable increase last year, driven by rising electricity demand and a rebound in coal power. China, the European Union, India, Russia and Indonesia were relatively flat.

The report found some genuine progress. Renewable energy capacity has grown about three times faster than projected in 2015, and energy-related carbon dioxide emissions have risen about 40 percent less than expected a decade ago. Skeptics of aggressive climate targets argue that energy affordability and reliability must come first, especially with fuel prices high; the report estimates that each five years of delay in cutting emissions locks in about another 0.1C of warming.

The report also found that about 95 percent of countries missed the February 2025 deadline to submit pledges for 2035, though by Sept. 1 of this year 124 countries, covering about three-quarters of global emissions, had filed new plans, Carbon Brief reported.