And it's contagious. Several of my peers (who aren't ultra-green types) bought electric cars or installed solar roofs after I talked about my EVs, and even some of their peers bought electric cars after talking to them. Individual action builds consensus on the importance of political action, too, as it is tangible proof that a transition to a low-carbon economy isn't just possible but attractive.
As far as plastic waste:
We can just replace drink straws with biodegradable plastic of the same performance. Techno solutions work. It's how we fixed ozone depletion.
Not trying to suggest you can create structural change here, but just as a product of being an American consumer you have a larger power to reduce GHG emissions than most of the other 6.6 billion people on the planet.
On plastic waste specifically, I think there is far more consumer awareness and consciousness than where I am now, Japan. Everything is in bags in bags in bags.
also the elephant in the room is that an individual in the US has little to no control over huge sources of pollution apart from feel good activism (look at this! i'm using a paper straw! I saved 2 turtles this morning y'all! what? can i drink though the paper straw? naaaw dog - it's mushy after 5 seconds but the turtles)