WORLD NEWS
Global warming will cross 1.5°C within years — UNEP maps a path back down
In a report dated September 2, the United Nations Environment Program (UNEP) assessed that it has become virtually impossible to avoid the average global temperature exceeding 1.5°C above pre-industrial levels within a few years. Even the most optimistic scenario sees it peak at around 1.8°C and then fall back down through strong reductions and carbon dioxide removal.
This does not mean that all climate goals become meaningless once we exceed 1.5°C. Lower peaks and shorter overshoot periods reduce the risk of damage and irreversible changes, but later lower temperatures do not restore all losses incurred during overrun periods.
What does an overshoot pathway mean?
In the report, overshoot means the full pathway in which warming crosses 1.5°C, reaches a peak and then declines. It deals with long-term averages, not annual temperature records, and the key is how high you climb and how long you stay there. UNEP compared current policy with several pathways in the near future and determined that the likelihood of exceedance was very high.
Why 1.8°C even in the best case
Even in scenarios where countries meet all of their most ambitious climate commitments, the peak is set at around 1.8°C. Other scenarios exceed 2°C. This does not mean that 1.8°C is a safe line, but rather that it is the lowest peak among the available options. The peak could be higher if promises are not translated into real policies and emissions reductions.
How can temperatures decline after the peak?
First, we must rapidly reduce fossil fuel use and other greenhouse gas emissions to bring net emissions close to zero. The remaining carbon dioxide must then be removed from the atmosphere through forest and soil restoration and verifiable removal technologies to lower temperatures. Removal is not a shortcut to reduction, and there are significant uncertainties about scale, cost, competition for land, and sustainability of storage.
Why do we have to adapt at the same time?
Excess periods result in heat waves, sea level rise, ice loss and increased pressure on ecosystems. Even if temperatures drop in the future, changes in sea level and some ecosystems may not be restored quickly. Therefore, UNEP explains that along with reducing emissions, we must simultaneously strengthen adaptation such as early warning, health, urban and water management, and protection of vulnerable areas.
What to check next
This report is not a document predicting temperatures for a specific year, but rather an evaluation comparing the risks of each policy path. Follow-up data will need to confirm whether each country’s new reduction goals translate into actual laws, budgets, and energy plans, when global emissions will peak, and how much carbon dioxide removal will increase on a verifiable scale.
Primary sources and independent checks
UNEP Limiting Overshoot report
UNEP official release and key figures