On a personal level basis, would you allow your own house to be devastated? As simple as not cleaning it for a long time, or abusing the furnitures you have, or by neglecting maintenance; would you? That is the same as our world, only on a larger scale; your home, your responsibility, the world, our responsibility. Definitely save the world.
The wording you used was "only on a larger scale." That is exactly what I was talking about when I said "so that you live to be at least 1,000 years of age."
While a house is larger than you are, you or your builder know all the ins and outs of the house. You can make successful repairs any time you want. But you don't know more than a tiny, tiny fraction of the repairs necessary to make your body live longer. Nature is way beyond our limits, presently.
Once we have the technology (or whatever) that it takes to live for a thousand years, then we might have enough of what it takes to save the earth. After all, if you are going to die in a couple more decades, you certainly aren't saving the earth for yourself, and you aren't really saving it for anybody who only lasts 100 years or less.
Forget saving the earth. Not only can you not do it, but you don't even know what you are talking about when you suggest how to try.