The Biden/Harris administration did a lot, starting with Harris casting the deciding vote for the Inflation Reduction Act., a key piece of climate legislation. We even saw major cuts to the leasing of federal lands for coal, as well as big cuts to oil and gas leasing
By contrast, Trump appointed a coal lobbyist to run the EPA and took steps to increase not just greenhouse gas emissions, but a wide variety of human-impacting pollutants, is surrounded by people who want to eliminate any effort to address the climate problem, and solicited a billion-dollar bribe from the oil industry
Harris may not have done enough yet and some of the language she uses about fossil fuel extraction is designed to appeal to people who still depend on oil to get to work, but the choice is very clear. Vote for Harris — and volunteer if you can
Sure.
But Biden is in office right now.