KEY CONCEPTS On January 20, 2021, President Biden announced that the U.S. is rejoining the Paris Agreement—an international agreement designed to avert catastrophic climate change. The central goal of the agreement is to hold global average temperatures to well below 2°C (3.6°F) above pre-industrial levels, and to pursue efforts to limit warming to 1.5°C (2.7°F). It was an amazing feat to pass the Paris Agreement, but the work ahead won’t be easy. A 1.5°C target would require a global emissions decrease of 7.6% per year from 2020 to 2030, or a decrease of 2.7% per year for the 2°C target. Current NDCs put us on track to reach around 3.2°C by the end of the century, overshooting our 1.5°C/2°C target. But new developments like net-zero pledges and the opportunity to incorporate green initiatives into COVID-19 recovery move us closer to achieving our goal.