https://www.ipcc.ch/pdf/assessment-report/ar5/wg2/drafts/fd/WGIIAR5-Chap10_FGDall.pdf
See Table 10-9 on page 80 (pointer from pages 34 and 35).
Also, see Table 10-B-1 on page 82.
Qualitatively, page 36 states: "In sum, estimates of the aggregate economic impact of climate change are relative small but with a large downside
risk."
If you want to feel optimistic about future possibilities there's this on carbon capture
http://nextbigfuture.com/2016/01/nanofactory-solution-to-global-climate.html
Also
There is a U of C professor that proposes taking a giant hose to space and blowing metal shavings into the atmosphere to emulate a volcanic eruption- seems like it would be a more cost effective way to deal with tail risk.
https://www.ted.com/talks/david_keith_s_surprising_ideas_on_climate_change?language=en