The 2015 Paris Agreement has established an ambitious long term temperature goal of: "Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C, recognizing that this would significantly reduce the risks and impacts of climate change". Associated with this there is a significant research gap on the nature, benefits/costs and feasibility of a 1.5 degree world. It is clear that in some sectors of the global environmental system benefits between 1.5 and 2 degrees (or higher) will be seen, for instance in sea level rise. But for other sectors there is an urgency to understand what the scientific community can say with confidence about impacts at differential levels of warming, including the health, economic, hydrological, crop and energy sections. This will be a central challenge for, amongst other reports, the 2018 Special Report on 1.5°C, that the IPCC has commissioned following the Paris Agreement.

In addition to the challenge of understanding impacts and avoided impacts in a 1.5°C warmer world, we need a carbon roadmap to maintain a chance of getting there, i.e. to support climate stabilisation well below 2°C above pre-industrial levels. Such a roadmap must involve deep decarbonisation, i.e. strategies to create the conditions to drive exponential transitions towards a carbon-free economy. In addition, climate stabilisation will likely rely on carbon removal technologies through measures such as bioenergy with capture and storage. The roadmap also needs to consider the stability and resilience of existing carbon sinks, and any potential for enhancement of these sinks.

This session will dive into both challenges: understanding impacts and avoided impacts in a 1.5°C warmer world and sketching out a roadmap of how to get there.