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The United Nations Environment Programme says the world will likely exceed 1.5°C of global warming within the next few years. Its new report urges governments to limit the size and duration of the overshoot through rapid emissions cuts, adaptation and carbon dioxide removal. UNEP says countries should continue working toward eventually bringing global temperatures back below 1.5°C.
The United Nations Environment Programme has issued a stark new assessment of the global fight against climate change.
The agency says exceeding 1.5°C of warming is now widely considered unavoidable under current policies and near-term trends.
The new report does not call for abandoning the Paris Agreement’s temperature goals. Instead, it urges governments to limit how high temperatures rise and how long the world remains above 1.5°C.
UNEP released Limiting Overshoot: Navigating exceedance of 1.5°C and pathways towards return on Sept. 2. The report outlines what the agency calls an “overshoot, peak and decline” pathway.
Under that approach, countries would rapidly cut greenhouse gas emissions, limit peak warming and eventually reduce global temperatures. UNEP says carbon dioxide removal could also play a role alongside deep emissions cuts.
The findings mark a significant shift in how international climate officials describe the world’s remaining options. Scientists have long warned that continued emissions from coal, oil and natural gas would make the 1.5°C target increasingly difficult.
Now, UNEP says policymakers must prepare for a period above that level while working to minimize the damage.
Report outlines a new path
Moreover, the report defines overshoot as more than simply crossing a temperature line. UNEP describes it as a longer pathway involving exceedance, peak warming, a subsequent decline and eventual stabilization.
The agency says the goal should be to keep both the peak temperature and the duration of overshoot as low as possible. Higher temperatures and longer periods above 1.5°C would increase risks for people, ecosystems and economies.
UNEP said the world experienced its first calendar year above 1.5°C of warming in 2024. However, scientists generally measure long-term climate change over decades rather than a single year.
The agency said the signal remains clear. The world is moving toward a future warmer than the Paris Agreement’s preferred target.
According to UNEP, even the most ambitious pathways now point toward a period of overshoot. The agency said warming could peak at about 1.8°C under its best-case scenario.
Reuters reported that UNEP projects a median warming of around 2.6°C by 2100 under current policies. The news agency also reported that returning below 1.5°C remains possible but highly uncertain.
The Associated Press similarly reported that the new UN assessment represents a recognition that the world will soon move beyond the 1.5°C level. AP reported that UNEP’s strategy now focuses on limiting the overshoot and eventually bringing temperatures back down.
What happens when the world exceeds 1.5°C?
UNEP warns that climate risks increase with every additional fraction of a degree of warming. The report says higher peak temperatures also increase the chances of crossing thresholds that could produce irreversible changes.
Those risks include more severe heat, floods and other extreme weather events. Ecosystems, glaciers and low-lying coastal communities also face greater pressure as temperatures rise.
The UN climate overshoot report stresses that a later decline in temperatures would not necessarily reverse all damage. Some losses could become permanent before global temperatures fall.
Reuters reported that UNEP warned, every year of delay, makes recovery harder. Each additional fraction of warming also increases the possibility of irreversible losses.
The report therefore rejects the idea that temporarily exceeding 1.5°C makes future climate action unnecessary. UNEP says the opposite is true.
The lower the peak temperature, the lower the risks. The shorter the overshoot lasts, the less likely the world is to cross certain irreversible thresholds.
UNEP said mitigation and adaptation must move forward together. Communities will need to reduce emissions while also preparing for climate impacts that are already occurring or expected in the future.
UN climate overshoot report calls for faster emissions cuts
The report says rapid and sustained cuts in greenhouse gas emissions remain the foundation of any effort to limit warming. UNEP specifically points to reductions in carbon dioxide and methane emissions.
The agency says governments must continue moving toward net-zero emissions. It also says future pathways may require long-term net-negative emissions to help lower temperatures.
Carbon dioxide removal, or CDR, would play a role in that process. UNEP describes CDR as removing carbon dioxide from the atmosphere and storing it through methods such as afforestation and other approaches.
However, UNEP says carbon removal cannot replace immediate reductions in emissions. Reuters reported that the agency views carbon removal as critical to controlling temperatures but not as a substitute for deep emissions cuts.
The strategy can be summarized in three broad steps:
- Cut greenhouse gas emissions quickly and sustain those reductions.
- Limit peak warming and shorten the period above 1.5°C.
- Use carefully governed carbon dioxide removal to support a long-term decline in temperatures.
UNEP Secretary-General António Guterres said recent extreme heat, wildfires and floods offer a warning about future climate risks. He called for making any overshoot above 1.5°C as small and short as possible.
The Paris Agreement goal remains in place
The new report does not mean the United Nations has abandoned the Paris Agreement’s climate goals. UNEP explicitly says exceeding 1.5°C should not become an excuse for resignation.
The Paris Agreement calls for countries to hold the increase in global average temperature well below 2°C. It also calls for efforts to limit warming to 1.5°C above preindustrial levels.
UNEP says that goal remains a cornerstone of the agreement. The agency now argues that countries must work toward returning below 1.5°C after an expected period of overshoot.
That distinction is important because climate scientists do not treat 1.5°C as a point where all consequences suddenly begin. Risks increase as temperatures rise, and the severity of impacts generally grows with additional warming.
The UN climate overshoot report therefore focuses on reducing harm at every stage. A lower peak temperature could mean fewer losses, while a shorter overshoot could reduce the chances of permanent damage.
UNEP’s 2025 Emissions Gap Report had already warned that nations remained far from the Paris Agreement’s goals. That report said faster and larger emissions reductions were needed to keep a return to 1.5°C by 2100 within the realm of possibility.
What the report means for the global climate debate
The report arrives as governments continue debating how quickly to reduce fossil fuel emissions and expand cleaner energy sources. The new assessment gives policymakers a more direct description of the challenge they face.
The central question is no longer only whether the world can avoid crossing 1.5°C. UNEP says leaders must now also determine how far temperatures rise beyond that level and how quickly they can bring them back down.
The Associated Press reported that the consequences of additional warming could include greater stress on food and water systems, ecosystems and coastal communities. The report also warns about potential climate tipping points that could become more likely as temperatures increase.
The Guardian also reported that UNEP’s assessment warns there are no good outcomes above 1.5°C, with higher warming creating greater risks for glaciers, food production, human health and infrastructure.
For the United States and communities across the Midwest, the broader findings add to an ongoing discussion about extreme weather preparedness and infrastructure resilience. Cities and states continue facing decisions about flood protection, heat preparedness and emergency response.
UNEP’s message remains focused on urgency rather than surrender. The agency says crossing 1.5°C would increase risks, but every reduction in future warming could still prevent additional damage.
The world may no longer have a clear path to avoiding an overshoot, according to UNEP. But the report says governments still have major decisions to make about how severe that overshoot becomes.
FAQs
What is the UN climate overshoot report?
The United Nations Environment Programme released a report examining what happens if global temperatures exceed 1.5°C above preindustrial levels. The report outlines ways to limit peak warming and eventually reduce temperatures.
Has the world already permanently exceeded 1.5°C?
UNEP says the world is likely to exceed the 1.5°C threshold in the near future. A single year above that level does not necessarily mean the long-term global temperature average has permanently crossed it.
What does climate overshoot mean?
Climate overshoot refers to a period when global temperatures rise above a target before potentially declining later. UNEP says limiting both the peak temperature and the length of the overshoot could reduce climate risks.
Can global temperatures return below 1.5°C?
UNEP says returning below 1.5°C remains a long-term possibility under ambitious climate action. The pathway would require rapid greenhouse gas reductions and potentially large-scale carbon dioxide removal.
