Climate engineering, also called geoengineering, is the idea of deliberately intervening in Earth's global radiation budget with the goal of reducing some of the risks of accumulating greenhouse gases. The two most frequently discussed possibilities are injecting aerosols into the stratosphere or adding aerosols to low marine clouds, both of which would reflect more sunlight to space; other possibilities include artificially thinning cirrus cloud cover to increasing outgoing longwave radiation. This conference will focus on the scientific questions associated with this set of technologies with the goal of fostering a better understanding of their efficacy and risks.