Are we spending on climate change? I see a lot of greenwashing, but it's more marketing than spending.
This said, I think you kind of miss a few points regarding climate change. First, it hasn't happened yet, it's just starting. We are living a mass extinction right now, and that's not a computer model or some prediction; that's a fact: we can count how many trees, mammals and insects have already disappeared (something like 75%). That's not the climate change problem, it's the biodiversity problem. If we magically removed the excess of CO2 from the atmosphere today, we would still be living a mass extinction. Just because of habitat loss (for other species obviously), which is due to how we live. We are destroying the planet, that's a fact, and that's before taking into account climate change. The solution to that? Produce less, consume less. There is no serious technological solution, because technology is the problem.
Then there is the energy problem: fossil fuels are going down (we passed conventional peak oil in 2008, general peak oil is about now, LNG is close) and we don't have serious alternatives. That will threaten our whole society. Solution? Prepare to do with less energy, meaning that we won't be able to produce as much, meaning that it actually helps the climate change problem -> that's fortunate.
Finally, for both of those existential problems, they exist because of how we actively behave (as opposed to a potential asteroid that doesn't care about our actions). So of course it seems like we should do something. But it's much harder than the asteroid: for the asteroid, we should actually spend money building a solution. For the biodiversity/climate, we should generally produce less, which is not compatible with growth.
Somehow we do the opposite of what we should: we don't do anything about asteroids, but we should. We do a lot of stuff that is destroying the planet, and we should not. Because we are short-sighted and looking for profit, not long-term (mid-term, at this point?) survival.