Not sure it's been mentioned on this thread yet, but one issue that's going to be an early issue for Biden is that, due to a combination of factors (but largely by design) a lot of the executive branch and federal agencies have been pretty hollowed out. They've lost a lot of the people who knew how to work the levers of government, and alleviating agency dysfunction will have to be done at the same time as rapid response on covid and other topics.
So... he's got a pretty tall task ahead of him.
Senate also remains (for now) without a power-sharing agreement between Sens. Schumer and McConnell, which will slow things down considerably (even more than usual!) and require Harris to be pretty much everpresent on the Senate floor until they get that hashed out.
What he really needs to do is start rolling back all the insane shit Trump did during his presidency. Close national parks and reserves to drilling exploration, again. Put environmental regs back in place, again. The list goes on.
Don't worry, he's on this. His chief environmental staff aren't the
most environmental, but the initial signs on undoing damage are pretty positive. They've even put out a list this morning (unfortunately lost for the moment in transition between the transition website and the new official WH website) of prominent Trump actions they're working to rectify.
Edit: He'll be signing his first set of Executive Orders (EOs) a little after 5 PM today, which should include several on environmental topics among other pressing issues.