It's a little more nuanced.
1. Some believe in climate change, some don't. Some do but don't think humans contribute much. Some think humans contribute enough but are unsure how much change we can contribute.
2. Nothing from American politics can be done to solve global climate change. You can solve regional environmental problems, like how Los Angeles cleaned up its air and water, but Los Angeles has no control on how much garbage India sends into the atmosphere and never will.
If there is a solution, it would come from technology, not voting for politicians.
Whatever helps you sleep at night Adam