What do you mean by a 'non-trivial amount of influence'? Sure, we can ask our employers to enforce climate-friendly practices and talk to friends and family, but even protesting companies that contribute the most to pollution doesn't provide much relief as they either ignore the protests or make small changes that give them positive PR and make the less active people happy to stop trying.
What steps can a random person take to actually help the planet? I'm asking this without a shred of irony or doom and gloom, I legitimately would be happy to help stop the crisis but the only thing I can think of is planting dozens of trees every year.