Global temperatures are on course to repeatedly cross the internationally agreed climate threshold and set a new all-time heat record within the next five years, according to projections released by the World Meteorological Organization.
The WMO, in a report produced with the United Kingdom’s Meteorological Office, put the probability at 75% that average global temperatures between 2026 and 2030 will exceed 1.5 degrees Celsius above pre-industrial levels — the ceiling established by the 2015 Paris Agreement as the upper boundary of manageable warming. That threshold, measured as a 20-year average, was never intended as a hard line but as a benchmark beyond which harm to ecosystems, human health, and food systems becomes significantly more severe.
The near-term outlook is even more pointed: there is a 91% chance that at least one of the next five years will individually surpass the 1.5-degree mark, and an 86% probability that one of those years will exceed 2024’s record as the hottest in recorded history.
“It’s important to note that (1.5) is not kind of a cliff edge that we’re going to fall off,” said report co-author Melissa Seabrook, a climate scientist at the UK Meteorological Office. “Every kind of 0.1 of a degree has more and more severe impact.”
Seabrook pointed to unusual heat gripping parts of Europe this week as an illustration of conditions already arriving ahead of projections.
The report draws on roughly 200 simulation runs across 13 climate models and projects that each year between now and 2030 will land between 1.3 and 1.9 degrees Celsius above late 19th-century baselines. A strong El Niño — the natural Pacific warming pattern that amplifies global temperatures — is expected to form soon and may persist through 2028, making 2027 a likely candidate to break the 2024 record, Seabrook said.
Should the five-year average exceed 1.5 degrees, it would represent a warming rate of roughly a quarter of a degree Celsius per decade — markedly faster than the approximately 0.2 degrees per decade recorded in prior periods. Seabrook acknowledged that climate scientists are actively debating whether global warming is genuinely accelerating, adding that confirming the trend would be “obviously quite scary.”
Friederike Otto, a climate scientist at Imperial College London who was not involved in the report, described what a sustained breach of the 1.5-degree threshold would mean in practical terms. A full year above that level, she said, “means a whole range of extreme weather events, probably many so hot/wet/dry that it exceeds anything we’ve experienced in the past and thus crucially, anything our city planning, agriculture etc. has anticipated.” She added: “This will mean many people will lose their lives, we are in for a lot of food price shocks, and more intense wildfires.”
The Arctic is projected to bear some of the sharpest consequences. Warming there is advancing at 3.5 times the global average rate — a dynamic driven by diminishing ice and snow cover that previously reflected solar energy back into space. Arctic winters between 2020 and 2025 were already 1.2 degrees Celsius warmer than the 1991–2020 norm; the WMO projects that the next five winters will average 2.8 degrees Celsius above that same baseline. Summer sea ice coverage is expected to keep shrinking.
“As the temperature warms, more sea ice melts, the worse this makes it,” Seabrook said.
The Amazon basin faces a different but equally concerning trajectory. The report forecasts hotter, drier conditions across the region that would escalate wildfire risk and potentially transform the rainforest — currently a significant absorber of carbon dioxide — into a net emitter. Africa’s Sahel, by contrast, is expected to receive above-normal rainfall, raising flood concerns.
UN climate chief Simon Stiell framed the findings in terms of current policy failures. “Despite the progress of recent years, it’s clear that global heating is still outpacing global efforts to contain it,” he said. “Whether it’s extreme heat, mega-storms, floods, massive wildfires or droughts hitting food supply and prices, every nation is already paying a huge price from this global climate crisis.”
A UN science assessment published after the Paris Agreement found that ecosystems including coral reefs and glaciers face severe stress at warming levels that may once have seemed distant but are now projected within the decade.
