Climate change and its dramatic consequences

Climate change is showing its claws. The last twelve years were the warmest since records began. 2025 was the third-warmest year, with a mean temperature that was 1.34°C above the 1850–1900 average. In the record-high year 2024, the mean temperature was around 1.5°C above pre-industrial levels.

Last year, natural disasters caused high losses totalling US$ 224bn, though less than in the previous year. However, it was only by chance that the world was spared more extreme losses in 2025, as no severe hurricanes hit the US coast. Wildfires, severe thunderstorms and floods dominated the loss statistics. These “non-peak perils” alone caused US$ 166bn in total losses, including US$ 98bn in insured losses. The scientific community largely agrees that such weather disasters are becoming more severe and more frequent in many parts of the world.

The current scientific consensus is that anthropogenic greenhouse gas emissions since the beginning of industrialisation are almost entirely responsible for rising temperatures in the atmosphere and oceans. Global warming has various consequences:

• Sea ice and glaciers are melting. The sea level is rising at an accelerating pace at a current rate of 4.7 mm per year on average, according to the World Meteorological Organization (WMO). This trend increases risks in connection with storm surges, as it means that even weaker tidal waves could spill over levees that haven’t been modified.
• Higher temperatures result in greater evaporation. Air that is 1°C warmer can absorb about 7% more moisture. Coupled with the higher energy content in a warming atmosphere, this leads to more severe weather disasters.
• As weather extremes become more frequent and/or intense, losses will increase unless specific mitigation measures are implemented. Construction engineering measures are one possibility, as are changes in land use.
• There is compelling scientific evidence for the influence of climate change on severe thunderstorms accompanied by hail in Europe, on wildfires in California, and on heatwaves, droughts and heavy rainfall.
• In recent years, tropical storms (called hurricanes, typhoons or cyclones, depending on the region where they occur) have been accompanied by increasingly extreme precipitation. There are also indications that, while the total number has remained largely unchanged, the proportion of especially severe storms is on the rise.