On September 2, 2026, the UN Environment Programme (UNEP) released a new report, "Curbing Overshoot: Responding to Exceeding 1.5°C and Pathways for Returning from It" (provisional translation). WWF Japan introduces part of its content in an easy-to-understand way.
According to the explanation, global average temperature has already risen by about 1.4 degrees compared with pre-industrial levels, and it is almost certain to exceed the Paris Agreement's 1.5-degree goal within a few years. Even in the most optimistic scenario, in which all countries' pledges are kept, the rise is projected to reach 1.8 degrees. In 2024, the temperature exceeded 1.5 degrees for a single year for the first time.
On the other hand, it is not impossible to bring down a temperature that has risen, if carbon dioxide is removed from the atmosphere using natural processes and technology. A pathway in which the temperature temporarily exceeds 1.5 degrees and then returns to below 1.5 degrees is called "overshoot." The report summarizes measures to keep the exceedance to a minimum, as well as the risks and adaptation measures in a world beyond 1.5 degrees. WWF Japan stresses that exceeding 1.5 degrees is not "game over," that the top priority is to cut emissions right now, and that the 1.5-degree goal remains unshaken.
Key points
- Temperatures have already risen by about 1.4 degrees, and exceeding 1.5 degrees within a few years is almost unavoidable
- "Overshoot" is the pathway of returning to below 1.5 degrees, for example by removing CO2, after exceeding it once
- Even so, the top priority is "cutting emissions right now," and the 1.5-degree goal itself does not change
Why we are paying attention to this news
Those who suffer the most from climate change are people in developing countries, who have little capacity to prepare for droughts, floods and sea level rise. Whether temperatures exceed 1.5 degrees bears directly on many activities in international cooperation, including agriculture, water, health and disaster preparedness.
This report is important because it neither takes the view that "once we pass 1.5 degrees it is too late" nor that "it is fine because we can bring it back," but shows what we should do now to make the exceedance as small and as short as possible.
Editor's comment
We need to take seriously the fact that "exceeding 1.5 degrees is almost unavoidable," but I felt the point of this report is that it does not give up there and tries to map out a "pathway back." WWF Japan's explanation takes the specialist content one step at a time and is very easy to read.
It is an ideal article for grasping the basics of how climate change and international cooperation are connected. Please read the full text, and consider using it as material for classes or study groups.