Climate change is real, but fighting Bitcoin won't stop it or even meaningfully make the problem smaller. There are plenty of other areas where meaningful change is possible and where advocating for change would make more sense.
Bitcoin is not the only challenge to climate change, there are many other challenges even with more effect on climate than just bitcoins. They are just a group of individuals who have misplaced priorities and have been misled because of misinformation or under information about the major causes of climate changes. If they have had proper information, they would channel their energy plus resources to campaigning about Increasing deforestation and increased combustion of coal, oil and gas which are leading causes.