Adapting to climate change is an increasingly urgent policy priority in lower- and middle-income countries. This systematic review summarizes the current state of the literature on adaptation to climate change, and conducts a quantitative meta-analysis of the effectiveness of climate adaptation. The meta-analysis reveals that observed adaptations offset 46 percent of climate losses on average, with firms using more effective adaptation strategies than households and farmers. The review identifies several key lessons. First, purely private adaptations to climate shocks tend to be less effective than those from public infrastructure and services, although neither by itself is generally sufficient to fully offset the effects of climate change. Second, some adaptations may reduce climate losses in the present, but in the long-run, households, firms, and farmers might be better-served by reducing their climate exposure. Third, the literature tends to focus on adaptation by households and farmers, neglecting firms. Finally, productivity losses from climate shocks may be offset if capital and labor can adjust across sectors and locations, but constraints on these reallocations have not been sufficiently studied.