Study Shows Half a Degree Matters

European researchers have found substantially different climate change impacts for a global warming of 1.5°C and 2°C by 2100, the two temperature limits included in the Paris climate agreement. The additional 0.5°C would mean a 10-cm-higher global sea-level rise by 2100, longer heat waves and would result in virtually all tropical coral reefs being at risk.

“We found significant differences for all the impacts we considered,” says the study’s lead author Carl Schleussner, a scientific advisor at Climate Analytics in Germany. “We analysed the climate models used in the [Intergovernmental Panel on Climate Change (IPCC)] Fifth Assessment Report, focusing on the projected impacts at 1.5°C and 2°C warming at the regional level. We considered 11 different indicators including extreme weather events, water availability, crop yields, coral reef degradation and sea-level rise.”

Paul Saad