Federal spending is just shy of twelve billion as of 2014 plus an additional twenty-six billion [0] ,and has likely increased since then. Private funding is harder to measure. I also think there's a case to be made that many people are "integrating backwards", looking for a specific answer and finding the research to justify that. This always happens when an issue is politicized, and this issue is undoubtedly politicized.

[0] https://www.gao.gov/key_issues/climate_change_funding_manage...