Scientists caution no guarantees when it comes to overshooting 1.5°C

The paper highlights that while there are still pathways open to limiting warming to 1.5°C or lower in the long run, there is a need to ‘hedge’ against higher warming outcomes if the climate system warms more than median estimates. If we were to exceed 1.5°C, there are clear benefits to reversing warming by acting to achieve net negative emissions globally, the authors show. Achieving long-term temperature decline could lower sea level rise in 2300 by about 40cm compared to a situation in which temperatures merely stopped rising. A preventive capacity of several hundred gigatonnes of net removals might be required, they conclude.

Only rapid near-term emission reductions to bring emissions down and keep peak temperatures as low as possible can effectively limit damages, the authors stress. To achieve this, ambitious emissions reductions need to go hand in hand with scaled and environmentally sustainable carbon dioxide removal technologies. The findings underscore the importance of countries submitting ambitious new reduction pledges (NDCs). The study is the result of a project funded by the European innovation fund HORIZON2020.