There are a number of papers that support the idea that reflecting solar energy back out into space would offset the warming effect of atmospheric CO2. For a high-level overview of how it works and the state of the research, check out this GCCA Issue Brief. GCCA regularly publishes Issue Briefs on hot topics covering cool roofs and urban heat islands. This recent article in the San Francisco Chronicle also does a nice job summarizing the opportunity.
If you really want to dig into the details, check out the following papers in our Knowledge Base: