Under the Paris Agreement, Parties agreed to limit global temperature rise to well below 2°C, and pursue efforts to limit warming to 1.5°C. While some progress has been made in strengthening national climate targets and policies for reducing emissions, current targets are still insufficient to meet the Paris Agreement’s temperature goal. Strengthened 2030 and mid-century commitments are urgently needed. The G20—a group collectively accounting for around 75 percent of global greenhouse gas (GHG) emissions, 80 percent of global GDP, and two-thirds of global population—has an outsized role to play in addressing climate change.

This paper presents a set of scenarios that simulate different climate commitments made by G20 countries for 2030 and mid-century and the resulting impacts on global temperature rise. The analysis finds that if all G20 countries set ambitious, 1.5°C-aligned emission reduction targets for 2030 and reach net-zero emissions by 2050, global temperature rise at the end of the century could be limited to 1.7°C, keeping the 1.5°C goal within reach. 

Executive Summary:

  • Current submitted nationally determined contributions (NDCs) together with legally binding net-zero commitments put the world on a trajectory to 2.4°C of warming by the end of the century.
  • Additional 2030 and net-zero pledges that have been announced by the G20 countries but not yet formalized in the NDCs or binding net-zero targets could lower projected temperature rise in 2100 to 2.1°C, if fully implemented. This is an important step in the right direction, but still far from sufficient to meet the Paris Agreement's 1.5°C temperature goal.
  • If all G20 members were to adopt mid-century net-zero commitments and align their NDCs with a 1.5°C pathway, end-of-century global warming could be limited to 1.7°C.
  • With this 0.7°C drop, down from 2.4°C under current commitments, G20 countries could collectively close three quarters of the temperature gap to 1.5°C, keeping it within reach.
  • To ultimately achieve the 1.5°C goal, ambitious action from non-G20 countries is needed too, as well as efforts to curb emissions from international aviation and shipping.
  • Achieving ambitious targets will require developed countries to substantially ramp up financial support to developing countries to help reduce emissions and build resilience against climate impacts. G20 developed countries have a particular responsibility to step up their public finance and mobilize private finance for international climate action, to close the gap to the commitment of $100 billion per year and go beyond.