We know that burning fossil fuels is a part of the reason for climate change, the proportion of man vs nature is not precisely known, but it's not none. The effect that we can each have on reducing climate change is minuscule, but it is not none. Internal combustion engines will be with us for a long time to come, as in some applications there is no practical alternative - yet. But, the move to reduce "lifestyle only" emissions, smaller more efficient personal vehicles, and electric vehicles where they are practical will help, at least a minuscule amount, and it will redirect society's priorities over time.
I come from aviation, we love big snarky piston engines. But, that time has passed. I know that needless consumption of fuel harms the climate, and I know that the climate is changing because it is being harmed. I see reports if worsening wild fires, rain storms, and I understand the dangers of sea level rise for some population groups. Where I live, those effects are minor on me, but not so for friends, they're suffering!
So, if I need to carry six people, and haul 10,000 pounds all the time, I'll buy a big pick up truck with those capabilities - it's justified. But, I don't. So I choose a small turbo diesel car, a small diesel tractor, ride my bike it it's practical, and otherwise don't burn fuel if I don't need to! To be honest, I still own a plane, which burns 8 gallons on hour, and I hardly use it. I enjoy my JD tractor, and excavator, which burn 2 gallons a day much more! It'll be a long time before piston engines are gone, but needlessly big should be a thing of the past....