When Joe Biden delivered his first speech as president-elect two weeks ago, he focused on his mandate to “marshal the forces of science and the forces of hope in the great battles of our time.” Climate change was high on that list. After another year of unprecedented climate disasters, Biden will enter office with the most ambitious plans of any incoming president to wean our country off fossil fuels. To deliver on his promises of “getting climate under control,” Biden will need to follow the prevailing science that suggests the United States achieve about a 45 percent reduction in its greenhouse gas pollution by 2030.