“More UV radiation kills off some of the oceans’ plankton, which produce dimethyl sulfide, one of the primary atmospheric chemicals involved in cloud formation, and fewer clouds mean less rainfall.”
...and...
“The findings indicate that phytoplankton will then produce more DMS(dimethyl sulfide) in response to this increased ultraviolet radiation, causing increasing cloudiness and mitigating the effects of global warming.”
More UV results in more plankton, and also simultaneously results in less?
Go to the second link.