That's where you're underestimating China. They are the biggest threat to US hegemony here and beyond.

And they have the luxury of not really having to give a damn about climate change activists that are anti-space exploration. Because as soon as an activist protests a Chinese mission to build a moon base they'll be locked up before they can utter their first chant.

The US on the other hand doesn't have that luxury and has to navigate the increasing pressure of environmentalists which believe they are doing the right thing like yourself but fail to realise that good intentions do not always equal good outcomes.

Say the US were to bow to your demands and cease space exploration/habitation for the sake of climate change next thing you know an asteroid or nuclear war wipes us all out. Bye bye Earth and all that you hold precious on it that you sought to protect, all for naught because the US didn't get mankind to become an interplanetary species to ensure its continued existence thanks to the "save the planet fight climate change" types.

I sincerely feel those that are anti-space exploration and colonisation under the justification of climate change are misguided and you fall in that bracket.

And on top of all this is a lot of irony. Space exploration and advancement will preserve our planet and all species on it by allowing us to move polluting and environment damaging work off planet. Such as mining, mining asteroids (which have more minerals in them than the Earth does) we will no longer need to mine the earth when we can get most of our minerals from asteroids.

That is just one example of many where space exploration and advancement benefits our planet and the preservation of all species on the planet indirectly and sometimes directly.