TIL I’m a clueless grandma…

I think that depends on your skill, i.e. good planning, and obviously execution. If you’re really good, you don’t even get caught, although that might help politically as we currently see with Mangione

More effective would probably to buy yourself (or a person that has political potential/influence with the right intentions) into politics like president muskrat, and do well placed populistic propaganda against the actually evil fossil industry. You don’t even have to lie, just do some good rethoric speech, ads etc… We need policies on a larger level, and I think 10B$ should be enough to gain significant political influence for something that the major mass of people is already behind of, just needs a good spark. I think Thunberg has shown that. Not that we shouldn’t of course improve public transport in cities. Additionally do (employ) investigative journalism probably in the same process to give all of this a good foundation…

*Repurpose trash…

I doubt that kill is that cheap…

You’ll need 100 Musks

To reach a catastrophic level on all kinds of scales - including climate change…

If you mean the net-worth, you might be right, that amount of money might even have a measurable effect on human-made climate change.