–elect Kamala Harris By Jeffrey MervisMost U.S. researchers and environmental activists were ecstatic when Joe Biden emerged as the winner of the U.S.
presidential election on Saturday. They expect him to reverse a host of Trump administration policies they oppose and push for new steps to fight climate change.But when Biden is sworn in on 20 January 2021, his ability to advance an ambitious agenda will be constrained by his likely status as the first president in more than 30 years to take office without his party controlling both chambers of Congress.