Yes, but can it kill the earth or alter it? There are theories of what happens with a nuclear radiation and about how terrible it is. In the short term, yes, it kills. Kills lots and lots. But does it alter the earth? History shows us that it doesn't. Ground Zero for both Hiroshima and Nagasaki have folks living there. Long term, destruction of the earth? Not yet.First off, there are plenty of things human beings are capable of to change the world. The most notable of them would be splitting the atom, which everyone here knows led to the Cold War. While it is totally unrelated to CO2 pollution, I think it's quite opposite of your claim that there is nothing humans can do to change the world. Radioactive fallout kills everything.
I have lived through the biggest, baddest man made environmental disaster ever (at least this is what all the "experts" told me). Hundreds of oil wells spewing burning oil into the sky, or pouring oil into the ocean. Not one or two, but hundreds. They spewed forth their destructive power for months. The scientists and environmentalists all said it would not be cleaned up for hundreds of years and the damage would go on forever. However Red Adair and handful of well paid Americans cleaned it up in a few months. Capitalism works. Today, there is very little notice of the "environmental holocaust" that was the burning oil wells in Kuwait.
I have walked the beaches of Ocracoke Island, that had thousands and thousands of gallons of oil washed up on its beaches due to the sinking of the tankers in WWII. The description from an old lady who still lives there is that the oil would squish between your toes as you walked on the beach. She would play in the ocean until her and her friends got too oily, than go to a nearby store, wipe it all off, and then go out and play again. That beach today was voted as one of the most beautiful in the United States.
But it hasn't. All man has done, in all the year's he has been on this planet, has not changed it at all. The time we live in today is one of extreme cleanliness, compared to the past. In the past, before there were cars, thousands of tons of horse shit had to be removed from New York City streets each year. On top of that was thousands of gallons of piss from the same animals. The rivers were so polluted you could not touch it, and at times the rivers would catch on fire. Smoke from coal burning factories made a haze that was so thick you couldn't see, like a London fog. Smoke from trains wouldn't rise into the sky due to the thickness of the air and instead would roll over the train and hug the ground. If there was a time that we thought we could destroy the earth, it would have been then. Today's "pollution" is nothing compared to that age.The problem is that humans have changed the LEVELS of CO2 to a point that the earth's atmosphere will start changing as well.