These new Pathways to Specific Warming Levels (SWLs) inform the experiments of Global and Regional Climate modelling [WP3], Biophysical Impacts [WP4], and Risk Management of Tipping Points [WP9]. Input from our stakeholders has been key to allow us to better understand which regional targets and combinations of targets are of most concern.
We have provided clear information on the timing of potential future climate changes and socio-economic narratives, with particular detail on future development of the energy sector. We have also characterised uncertainty in the times at which existing climate model simulations reach specific warming levels (and levels of other relevant targets such as forcing, CO2 concentration and sea level rise). We have improved the consistency between the treatment of climate in Integrated Assessment Models (IAMs) and state-of-the-art global climate models, and assessed the impact of this on policy. We estimated alternative greenhouse gas emissions, concentrations, and forcing pathways that lead to similar SWLs, including clear narratives on aspects of the economic and technical feasibility of these pathways. And finally, we calculated the effect on the timing of reaching specific climate targets of additional biogeochemical feedbacks not typically included in the current generation of complex Earth System Models (ESMs) or Integrated Assessment Models (IAMs).