Abstract: Pathways for limiting global warming to 1.5° and 2°C generally involve net-zero greenhouse gas (GHG) emissions economy-wide near mid-century and halving emissions over the next decade. Updated pledges by countries and companies around the 2021 United Nations climate conference reflect this sense of urgency. The updated US pledge to reduce net emissions 50 to 52% by 2030 would represent a tripling of the pace of historical reductions.

We report on a six-model intercomparison of potential actions to reach the US target of at least 50% GHG reductions by 2030. This analysis helps identify which findings are more robust or uncertain given different model structures and input assumptions. Models highlight the central roles of clean electricity and electrification, the large scale of deployment needed relative to historical levels and scenarios with only current policies, and a range of benefits from near-term action.