To facilitate global climate governance, the Paris Agreement requires the ratified parties to update their nationally determined contributions (NDCs) every five years. However, the 24th Conference of Parties (COP24) in Katowice, Poland, and 25th Conference of Parties (COP25) in Madrid, Spain, ended with limited progress. According to the IPCC Special Report on the impacts of global warming of 1.5 °C, global temperatures are likely to reach 1.5 °C between 2030 and 2052, which would cause dramatic damage. Inaction to climate change will lead to substantial socioeconomic losses, implying the occurrence of a broader cost than sufficient action. A strategy that informs on countries’ potential losses due to lack of climate action may facilitate global climate governance.
This paper quantifies a distribution of mitigation effort whereby each country is economically better off than under current climate pledges. This effort-sharing optimising approach applied to a 1.5 °C and 2 °C global warming threshold suggests self-preservation emissions trajectories to inform NDCs enhancement and long-term strategies. Results show that following the current emissions reduction efforts, the whole world would experience a washout of benefit, amounting to almost US$126-616 trillion until 2100 compared to 1.5 °C or well below 2 °C commensurate action. If countries are even unable to implement their current NDCs, the whole world would lose more benefit, almost US$149–791 trillion until 2100. On the contrary, all countries will be able to have a significant positive cumulative net income before 2100 if they follow the self-preservation strategy.