A major international study has uncovered a growing health challenge linked to climate change, highlighting unexpected impacts, regional disparities and mounting pressure on healthcare systems worldwide.
The world has effectively lost the opportunity to keep global warming below 1.5°C without temporarily exceeding that limit, according to the latest assessment from the United Nations Environment Programme (UNEP), which warns that countries now face the challenge of limiting the scale and duration of overshoot.
The warning appears in the Emissions Gap Report 2026: The Point of Return, UNEP’s latest evaluation of global greenhouse gas emissions and climate commitments. The report concludes that a pathway keeping temperatures below 1.5°C above pre-industrial levels with no or limited overshoot is no longer achievable.
The finding marks a significant moment in global climate discussions because the 1.5°C threshold has been the central benchmark of international climate negotiations under the Paris Agreement. UNEP stresses that every additional fraction of warming beyond that limit increases climate risks and amplifies the impacts already being experienced worldwide.
The assessment arrives as countries continue to record exceptional temperatures. In 2024, global temperatures exceeded the 1.5°C benchmark for the first time. More recently, September 2026 became the second-hottest September ever recorded, with global average temperatures reaching 16.27°C, according to climate monitoring data cited in the report.
Despite mounting concerns, the latest emissions data presents a mixed picture. UNEP estimates that total global greenhouse gas emissions reached 58.4 gigatonnes of carbon dioxide equivalent in 2025. While that represents a slight decline compared with the previous year, the report notes that the reduction was minimal and masks deeper structural concerns.
The most troubling trend remains continued growth in fossil fuel emissions. Carbon dioxide released from the combustion of coal, oil and natural gas continued to rise during 2025, alongside increases in nitrous oxide and fluorinated gas emissions.
Fossil Fuel Emissions Continue Rising Despite Small Overall Decline
The report explains that the modest reduction in overall emissions largely resulted from lower emissions linked to land use, land-use change and forestry activities. A decline in biomass-burning emissions and reduced wildfire-related carbon releases compared with an exceptionally severe 2024 fire season contributed significantly to that outcome.
However, UNEP warns that global emissions have not yet reached a clear peak. Emissions from the world’s major economies remain a central concern. Members of the G20, excluding the African Union, account for approximately 76 per cent of global emissions, and their emissions excluding land-use changes increased by 0.7 per cent during 2025.
According to the assessment, 63 countries have reduced greenhouse gas output over the past decade, but 124 nations recorded increases over the same period. UNEP also notes that several countries with historically high emissions and elevated per-capita emissions have not yet reached peak pollution levels.
Rather than abandoning the 1.5°C goal altogether, the report argues that governments should now focus on reducing the extent and duration of overshoot. Under UNEP’s lowest-overshoot scenario, global emissions would need to fall by 18 per cent by 2030, 45 per cent by 2035 and 69 per cent by 2040 compared with 2025 levels.
The pathway would also require large-scale removal of carbon dioxide from the atmosphere to help bring temperatures back toward or below the 1.5°C threshold by the end of the century.
Climate Analytics Chief Executive Bill Hare said the message remains clear despite the increasingly difficult circumstances. According to Hare, governments must move rapidly to implement policies that reduce fossil fuel use, arguing that stronger action could help stabilise warming close to 1.7°C around mid-century before temperatures decline again later.
The report ultimately concludes that while avoiding an overshoot has become increasingly unlikely, decisions taken now will determine how severe future warming becomes and how quickly temperatures can eventually be brought back down.