UNEP: World Likely to Cross 1.5°C in Next Few Years; Urges Rapid Cuts and Carbon Removal

The United Nations Environment Programme said in a report released Wednesday that the world is now likely to cross 1.5 degrees Celsius of warming above pre-industrial levels within the next few years, a marker long treated as the most ambitious temperature goal in the Paris climate agreement.

In the report, “Limiting Overshoot,” UNEP said current global action to cut greenhouse gas emissions has not been fast enough to avoid crossing 1.5 degrees in the near term. Instead, it said climate policy should focus on making any overshoot as small and short as possible through immediate and sustained emissions cuts, faster adaptation to worsening climate impacts, and carbon-dioxide removal to bring temperatures back down later.

That approach, which UNEP describes as an “overshoot, peak and decline” pathway, does not treat 1.5 degrees as irrelevant. The aim, the agency said, is to minimize both the magnitude and duration of any breach and, if possible, return warming to at or below 1.5 degrees over the longer term.

Even in UNEP’s most optimistic scenario, global warming would peak at about 1.8 degrees above pre-industrial levels, with most other scenarios rising higher. The agency warned that additional warming raises the risk of major climate tipping points, including damage to ice sheets, disruption in the Amazon and changes to the Atlantic Meridional Overturning Circulation, or AMOC, a major ocean current system that helps regulate climate.

UNEP said carbon-dioxide removal, often called CDR, is “an essential part of the mix” but cannot replace cutting emissions at the source. Bringing temperatures back down to 1.5 degrees, it said, would require long-term net-negative emissions — removing more carbon dioxide from the atmosphere than humanity emits — as well as governance for how CDR is deployed.

The 1.5-degree benchmark comes from the 2015 Paris Agreement, in which countries agreed to hold warming to well below 2 degrees Celsius above pre-industrial levels and pursue efforts to limit it to 1.5 degrees. Scientists assess that goal over longer-term warming trends, not a single hot year.

That distinction matters because 2024 was widely reported as the first calendar year in which observed global average temperature exceeded 1.5 degrees relative to the 1850-1900 average. But that was a temporary, single-year exceedance, not necessarily a long-term breach of the Paris threshold.

Recent assessments have pointed in the same direction as UNEP’s report. The World Meteorological Organization said in May that there was a 91% chance that at least one year between 2026 and 2030 would exceed 1.5 degrees, and a 75% chance that the average temperature across the full 2026-2030 period would exceed that level. The Global Carbon Project also reported that fossil carbon dioxide emissions reached a record high in 2025, underscoring UNEP’s conclusion that current action is insufficient.

The report marks a shift in emphasis in the climate debate: less on whether 1.5 degrees can still be avoided entirely, and more on how much damage can still be prevented if the world overshoots it.

“There are no good outcomes if we remain above 1.5°C,” Inger Andersen, executive director of UNEP, said in the report’s release. “Across the globe, extreme heatwaves are already proving that climate impacts will strike faster, hit harder, and last longer - costing more lives and causing deeper disruption.”

U.N. Secretary-General António Guterres put the choice more bluntly: “This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead. We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition.”