Depending on where you live, they don't have to be the entire government. If they'd hold the majority they could easily work on environmental issues while leaving the rest of the government to their coalition partners. Some crazy people are, in the grand scheme of things, a lesser issue compared to climate change, which is way too much of a priority to let some of those stop you. It's rougher in countries like the US and their two party system, because of how much they engage in contrarian bullshit.