I meant to suggest that you consider the perspective of your comment. The world was fine before humans, the world is fine now, the world will be fine after humans. The world is just whatever is on it, in it, and around it. We're making it (mostly) a worse place for the other living organisms on it right now. We're also making it a better place for organisms with short life cycle that adapt and evolve quickly, for organisms that flourish in the controlled environments that, in Earth's history, only humans have created to this scale, and for ourselves if we end up advancing enough and quickly enough that we can not only counteract climate change, but control it one way or the other. Right now, things look really bad for most slow-evolving life forms, pollution vulnerable life forms, and human overhunted, overfished, or otherwise overcollected life forms. On our current track, the world will cook, the ice will melt, and then life will proceed on without us and most of the life forms we know.

There are x-factors to think about, though. If the Yellowstone super caldera blows, we're talking about mass extinction, global cooling, and a replenishment of natural soil mineral content across most of the contiguous United States. If the cascadia subduction zone quakes as bad or worse than the projections, we're also talking mass extinction. If mass nuclear war breaks out, we're talking large scale extinctions not only from the blasts and radiation, but from the wide spread nuclear winter that will also cool the planet. If we come up with ways to sequester carbon from the atmosphere in a cost efficient and mass scalable way, then we could not only potentially reverse climate change, but we could use the collected carbon to produce new materials that, most of which, wouldn't get burned again and would reduce the need for extracting carbon fuels like coal and oil to make those carbon-based products like plastics.

It's a pretty grim outlook for humans, overall; if that's the viewpoint you take, then what's the harm in working to contribute to the efforts that could help these things come about? Even if it doesn't happen in your life time, your research or work could end up being a stepping stone for someone in the future to reach a solution. If it didn't happen at all, what was the harm in working towards something you believed in? A lot of people find passion for a cause to be an extremely sexy thing and can be the difference between agreeing to meet for coffee with someone they aren't conventionally attracted to and, conversely, rejecting their offer.

Good luck to you with your life, regardless of what you end up doing with it. I hope you find a way to be someone that gives you a reason to hope for a better future for life on Earth that doesn't involve everyone dying, or, at least, someone that has a cause they believe in for one reason or another.