Ask HN: What's the best way to fight climate change as a Software Engineer?

Turn off your computer and all the computers you administer.

Use your skills to contribute to the renewable energy industry.

Eat more chickens and less cows.

Source: Before the flood https://www.youtube.com/watch?v=codqzJ4onGc

There's plenty of software engineering roles available to in the energy efficiency industry and more to come.