Just stop. All you are accomplished is dissuading people from trying. Even if we fail, some of us would rather go out feeling good about ourselves knowing that we actually tried. If we succeed, I want to be on the right side of history. If you want to drive a canyonero through a drive through to buy a double cheeseburger on your way to the airport to fly somewhere for a shopping trip: please keep it to yourself.
There is still hope
Most people want action. I can cite more than one source.
Things are starting to turn around. Not as fast as we need to, but we are seeing change
Some of us are parents and have a reason to fight with all we have
If things get bad, our kids will actually want to have a relationship with us if we cared enough to try
Many things that help are economically better on the micro and macro scales
Doomers are the fossil fuel industry's best friend-- even more than the deniers are. If enough people succumb to it, they don't even have to pay lip service to the problem. Doomerism means you can continue to pollute and not even try.
Who said you have to feel good about yourself? The point is that giving up will definitely doom us. Doing nothing isn't even an attempt at a solution.
Some of us aren't willing to give up, some people aren't sure either way, and saying, "It's pointless. Just accept your fate," doesn't help anyone. If you want to give up, that's 100% on you. If we are definitely doomed and don't know it (and the expert consensus doesn't share that opinion), I plan to go down swinging.
We have the numbers, there are plenty of talented and skilled people on them right side of things, we just need to find the will to do it.
Action follows belief. If you believe you can take that growling gerrman shepherd, you might just punch it in the teeth when it lunges and then put in a headlock and choke it out. If you don't believe, you're dog food. Enjoy a definite painful death of being eaten by a dog.
But I can prove that giving up will produce an almost certain negative outcome. If we can't prove what will happen through trying, then it is at least worth the attempt to try.