1.5°C Warming Limit: Urgency and Steep Emissions Cuts

NAIROBI — The world has lost the chance to keep global warming within the 1.5°C Warming Limit.

Moreover, the Emissions Gap Report, subtitled The Point of Return, concludes that exceeding the Paris aspirational limit is now imminent.

The report shifts focus to minimize the size and duration of overshoot toward the 1.5°C Warming Limit.

Additionally, it aims to establish a credible pathway back by the end of the century.

Moreover, in its lowest-overshoot scenario, peak warming would be about 1.7–1.8°C around mid-century, then decline.

Finally, there is roughly a fifty percent chance of returning to or below the target by 2100.

Achieving that pathway would require immediate, deep, rapid and sustained cuts in global greenhouse gas emissions: 18 percent by 2030, 45 percent by 2035, and 69 percent by 2040, all relative to 2025 levels. That translates to average annual reductions of about 5.7 percent over the next decade—steeper than earlier pathways outlined by climate scientists.

Implications for the 1.5°C Warming Limit

By contrast, full implementation of countries’ current climate pledges would deliver only 5–8 percent reductions by 2030.

They would deliver 11–15 percent reductions by 2035 from 2025 levels, challenging the 1.5°C Warming Limit.

That trajectory would leave the world heading toward about 2.6°C of warming this century.

However, under existing policies alone, warming could reach approximately 2.8°C.

Moreover, even if all pledges plus additional net-zero targets are met, the projection stands at around 2.1°C.

Global greenhouse gas emissions stood at roughly 58.4 billion tonnes of CO₂ equivalent in 2025, remaining essentially flat compared with the previous year. China, the United States and India remain the largest emitters. The report notes that every five years of emissions at current levels adds about 0.1°C to eventual peak warming.

Returning temperatures to 1.5°C would also demand large-scale removal of carbon dioxide from the atmosphere—on the order of 320 gigatonnes over the course of the century, equivalent to about eight years of recent annual CO₂ emissions. Experts caution that socioeconomic and technological challenges make the feasibility of such removals uncertain.

Despite the sobering outlook, the assessment emphasizes that opportunities to accelerate action have never been more abundant. Since the Paris Agreement was adopted, renewable energy has expanded far faster than earlier projections—solar photovoltaic capacity, for example, has grown seven times quicker. Climate policies in various countries and sectors have already delivered measurable emissions reductions. Evaluations of more than 220 policies show average cuts of about 9 percent in the electricity sector and 5–13 percent from economic instruments such as carbon pricing.

UN Secretary-General António Guterres underscored the dual message of urgency and possibility. “Overshoot is not surrender,” he said. “We can still keep it as small and as short as possible—and bring temperatures back below 1.5 degrees by the end of the century.” He called for stronger climate pledges and wider use of proven policies.

Inger Andersen, executive director of the UN Environment Programme, stressed that every additional fraction of a degree and year of warming above 1.5°C heightens risks of deadly floods, heatwaves and wildfires. “We must pull out all the stops to minimize peak warming and return to 1.5°C by the end of the century. This is possible,” she said. “We have a wealth of success stories showing that emissions can be cut quickly.”

The report builds on the first Global Stocktake under the Paris Agreement, which set goals including tripling renewable energy capacity and doubling the rate of energy efficiency improvements by 2030, transitioning away from fossil fuels, cutting non-CO₂ emissions such as methane, and halting deforestation. It provides benchmarks consistent with the lowest-overshoot pathway, including further expansions of renewables, deeper reductions in the share of coal, oil and gas in energy supply, and steeper methane cuts by 2035 and 2040. Coal-fired electricity generation, for instance, would need to fall sharply and effectively phase out globally by 2040.

The findings arrive ahead of the next major climate negotiations, COP31, scheduled for Antalya, Turkey. While new national pledges have increased in number, the report finds they have made only a negligible difference to overall temperature projections so far. Fewer than half of the world’s major economies are on track to meet their existing 2030 targets.

The assessment makes clear that while the window for avoiding any overshoot has closed, the window for limiting its severity and duration remains open—if governments rapidly scale up the policies and technologies that have already proven effective in cutting emissions.