This report reviews the current state of the literature on the differences in climate impact projections between 1.5°C and 2°C.
There are discernible differences for extreme weather events in particular on the regional level, impacts on unique and threatened systems such as coral reefs, water availability and tropical crop yields as well as abrupt shifts in the climate system and long-term sea-level rise risks. Limiting warming to 1.5°C would substantially reduce the impacts of climate change for the most vulnerable in particular in the Tropics, as well as in high-latitude regions. More science is required to improve our understanding of the impacts of climate change at 1.5°C and the avoided impacts when limiting warming to 1.5°C compared to 2°C or higher levels to provide a robust basis for the IPCC special report. Coordinated efforts by the scientific community are underway to address these issues and a wealth of new studies can be expected in time for the 1.5°C special report.