I do believe the biggest impact would come from regulating large companies and billionaires, but it’s not one or the other.
Anytime you have a chance to vote, take it, and vote for whatever option will be most likely to reduce the overall emissions. In most cases, this will probably mean voting for programs/parties etc that oppose conservatism.
In the US, neither party is serious about stopping climate change. They are both controlled by big oil, big car, etc.
I agree the the democrats are not nearly serious enough about stopping climate change, but the republican party is actively hindering efforts and definitely worse for the plant in the long run.
Neither party being serious does not mean one isn’t way worse than the other
You still need to hold the Dems feet to the fire. Just handing them your vote as the least worst option just means you’ll never be offered any good options. Make them work for it.