Exponential warming, at that.

No and no. It took society a long time to do this damage, I have faith that humanity is capable of fixing it. But it won't be fixed by you personally giving up straws, switching to canvas shopping bags, or riding a bike. That mind set was pushed by the fossil fuel companies to get people to blame individual behavior on societal failings. The solution is political. Voting is and organizing are the best individual behaviors to get results

That depends on how you mean that. If you mean it as "can one person fix this problem, like in some Hollywood movie?", then, the answer is "probably not". If the richest person in the world, who I will not name it of fear of unintentionally summoning them, were to start taking meaningful action today, we'd probably be reading an obituary by Monday.

But for the first question? No, we're absolutely not helpless. We as isolated individuals may not have a statistically favorable chance at fixing things. United as communities resisting possible suffering and extinction, we have a much better chance.

And as an individual, you can help. Humans are generally social creatures. The problems and their perpetuation are, at their root, caused by antisocial behavior. Showing others kindness and compassionately building relationships with those around you is one of the most significant ways that one can rebel and undermine efforts to keep us weak, divided, and incapable of changing things.

We can always throw a Molotov or two.

The way I see it, human society is a statistical-mechanical system and we're sources of noise.

So, if society is close to a bifurcation point or you personally are really loud (in case Xi Jinping is reading), then yes. Otherwise no.

Edit: I should specify that even if you can't save everyone you can probably save a few people. The question I'm trying to figure out for myself is how big a bifurcation point to target.

The only things allowing the big plastic and CO2 producers to continue as they are are public consensus, profit, and policy. When these change we will see a reduction.

We are starting to see more changes in public consensus. Because of this we are seeing more companies push some small changes. Unfortunately these changes often come at the cost of company profit.

When it is profitable to switch, or a cost reduction to switch we will see changes. Before too long renewable resources will be on par or cheaper than using oil/plastic bags. Then we will see more and more reusable, compostable, recyclable products.

Finally as another commentir stated governmental policy is a big one. Companies won't go against what is cheap and easy unless forced to. By enacting policies to reduce waste products, or subsidize renewable to make them cheaper we will see more companies jumping on board.

Individually continuing to reduce reuse and recycle is meaningful and shouldn't be abandoned, but a large percent of waste does come from the policies of the big companies using plastic.

Vote for the people that will enact these changes and push for the policies that will help all of us.