A multi-model analysis of long-term emissions and warming implications of current mitigation efforts

Researchers from PARIS REINFORCE (PR), including our own Dr. Annela Anger-Kraavi, have just published a new analysis in Nature Climate Change. The Climate Change Policy Group was supported by Cambridge Econometrics project manager Ms Ha Bui in this research.

The study investigates temperature outcomes of current policies and emission pledges, also known as Nationally Determined Contributions, using a range of IAMs to extrapolate the implied effort from 2030 to 2100 – one of the few studies to do so.

Across the models used in the study, they found that current policies lead to a 2.3-2.9°C of warming in 2100, while emission pledges lead to 2.2-2.7°C of warming. When incorporating the uncertainty in the climate response, this range increases to 1.7-3.8°C.

The study identifies a number of challenges, including how modelling users are not interested in hypothetical scenarios showing fossil fuel dependent futures with relatively little climate policy, and the common misuse of carbon pricing to represent climate policy in IAMs. For example, many IAMs place a large emphasis on technologies such as Carbon Capture and Storage (CCS) to mitigate climate change. The study by PR indicates that a high use of CCS might just be an outcome of using carbon pricing as a proxy for climate policies, whereas real-world policies may instead encourage the deployment of alternative technologies, such as wind, solar or electric vehicles.

The large uncertainties revealed by the study highlight how more effort is required to prevent reaching high global temperature increases. The authors hope that this study will lead to an increased focus on how to model current climate change efforts going forward, with the lead author, Ida Sognnaes, noting that the “false precision to climate outcomes given during COP26 may lead countries to believe they are making good progress, when the opposite may indeed be the case”.

Dr. Anger-Kraavi of the CCPG notes “These forward looking scenarios provide a good alternative to the business-as-usual scenarios that do not consider where the world is already heading in terms of emission reductions”.

Read the full paper on Nature Climate Change here, or access a free link version by clicking here. 

Alternatively, read about it on Forbes or Axios!