Pretty stupid way to do the math. Tell me whats the value of saving humanity? Care to do that calculation? And don't compare it to "Global Climate change" or any other boogieman. This is as real as tommorow. It WILL happen. It's the one type of planetary disaster we can actually try to prevent.
You forgot to tell us WHEN it WILL happen.
10 years, 100 years, 1000 years?
History tells us it's closer to a 1000 than to 100.