World must cut emissions 18% in four years to find a way back below 1.5°C – UN 2026 Emissions Gap Report

Countries must slash greenhouse gas emissions by almost a fifth (18%) by 2030 and 45% by 2035, compared with 2025 levels. Only then can they stop global heating from running far past 1.5 degrees Celsius (°C) and bring it back down by the end of the century, the United Nations said on Wednesday.

In its annual Emissions Gap Report, the UN Environment Programme (UNEP) said decades of weak action had made crossing 1.5°C "imminent and unavoidable". If deep cuts start now, warming could peak at about 1.7–1.8°C around the middle of the century, with roughly an even chance of falling back to 1.5°C by 2100.

"Overshoot is not surrender," UN Secretary-General António Guterres said in a message on the report. "We can still keep it as small and as short as possible."

Under the 2015 Paris Agreement, almost every country promised to keep global warming "well below" 2°C and to try to stop it at 1.5°C. The figure measures the rise in Earth's average temperature over many years, compared with the late 1800s, before factories and cars. UNEP now says that even if every country cut its emissions as hard as possible starting today, warming would still pass 1.5°C, because so much heat-trapping gas has already built up in the air. Scientists call this an overshoot: going above the limit for a while, likely for several decades, and then pulling temperatures back down. And on the policies governments actually have in place, the world is not heading for a small overshoot at all, but for about 2.8°C by 2100.

Figure 1. Where warming is heading by 2100 under different paths.

This is what climate change is. Burning coal, oil and gas, and clearing forests, releases carbon dioxide and other gases that trap the sun's heat like a blanket. The thicker the blanket, the hotter the planet gets. Above 1.5°C, the report warns, heatwaves, floods and droughts become more frequent and severe, bringing more heat deaths and economic losses. Every extra fraction of a degree also raises the risk of changes that cannot be undone, such as melting ice sheets, carbon escaping from thawing frozen ground, disrupted ocean currents and the loss of coral reefs. Coming back down will take more than cutting pollution. About 320 billion tonnes of carbon dioxide, roughly eight years of today's fossil fuel emissions, would have to be pulled back out of the air this century, and UNEP calls that uncertain.

The effects are already visible. The EU's Copernicus Climate Change Service said August 2026 tied July 2023 as the hottest month ever recorded, with an average global air temperature of 16.96°C, 1.65°C above pre-industrial levels. The world's oceans were also the warmest ever measured for an August. The World Meteorological Organization (WMO) warned on Wednesday that the El Niño now building in the Pacific "could be unprecedented in strength", and the UN says about 50 million people could face greater hunger as a result. The WMO also found that 2025 was one of Africa's warmest years on record.

Researchers at the University of Chicago's Climate Impact Lab estimate that the extra heat from this El Niño alone could cause about 451,000 additional deaths worldwide between June 2026 and February 2027. Nigeria faces about 31,400 extra deaths between September and February, more than any other country. Looking further ahead, the lab projects that Sahel countries such as Niger and Burkina Faso could see 60 or more heat deaths for every 100,000 people each year by 2050, a higher rate than malaria causes in Africa today. Rising temperatures are also moving malaria itself. A study in Nature, promoted by the University of Chicago and co-written by Climate Impact Lab researchers, found that some very hot West African and Sahel countries are becoming too hot for malaria-carrying mosquitoes, while risk is climbing in the cooler highlands of East Africa and in southern Africa. By 2100 it could rise by about 20% in areas such as the Rift Valley.

Table 1. The warming we are already living with

The outlook is bleaker than a year ago. UNEP's 2025 report, Off target, said warming could still be held close to 1.5°C if emissions fell 26% by 2030 and 46% by 2035 from 2019 levels. This year's edition, The point of return, says that chance "has been lost". Even if every country kept its climate plan, emissions would fall only 5–8% by 2030, and warming would reach 2.6°C by 2100. Last year the same calculation gave 2.3–2.5°C. UNEP blamed the change mainly on the United States leaving the Paris Agreement and on revised estimates of past emissions. Global emissions reached 58.4 billion tonnes in 2025, roughly level with 2024, and every five years of pollution at today's rate pushes peak warming up by about 0.1°C.

Table 2. One year on: what changed between the 2025 and 2026 reports

Figure 2. Global emissions since 1990 and where different paths take them.

"Every additional fraction of a degree and additional year of warming above 1.5°C increases climate impacts and risks," said Inger Andersen, UNEP's executive director. "So, we must pull out all the stops to minimize peak warming and return to 1.5°C by the end of the century."

Countries are moving, but slowly. By 1 September, 124 governments covering about 76% of global emissions had handed in new climate plans, up from 60 a year earlier. Every G20 member except Argentina, Saudi Arabia and the United States has now set targets for 2035, but only Mexico strengthened its target for 2030, and only six G20 members (China, India, Indonesia, Russia, South Africa and Türkiye) are on course to meet their 2030 goals. The Paris Agreement's main tool for closing the gap is the global stocktake, a check-up every five years on whether countries are doing enough together. The first, completed at the COP28 summit in Dubai in 2023, set goals such as tripling renewable energy and moving away from fossil fuels. The second runs until 2028, and the report urges governments to use it to set clear goals for 2035 and 2040.

Figure 3. The emissions gap: cuts needed versus cuts promised.

The report spells out where the cuts must come from. Electricity from coal must fall by at least 75% by 2035 and 95% by 2040. The energy the world draws from coal, oil and gas must drop by 55%, 15% and 5% respectively by 2035. Methane, a powerful heat-trapping gas from oil and gas sites, coal mines, livestock and rubbish dumps, must fall at least 25% by 2035, and road transport emissions by 20%.

Figure 4. What has to be cut, and by how much.

There is progress to build on. In 2025 renewables generated more of the world's electricity than coal for the first time, and solar power has been built seven times faster than forecast a decade ago. Before the Paris Agreement, the world was on course for almost 4°C of warming.

For Africa, the gap between cause and harm is stark. The world's least developed countries, many of them African, produce just 3% of global emissions, about 1.5 tonnes a person against a world average of 6.4 tonnes and 17.6 tonnes for each American.

Figure 5. Greenhouse gas emissions per person, 2025.