However, there is also the global cooling effect of aerosols (such as in nuclear winter). (realclimate.org)
The results also show these ancient lakes actually have a net cooling effect on climate over thousands of years. (fm.kuac.org)
Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from industrial times to 1950 and a small cooling effect from 1950 onward. (slideplayer.com)