Developing countries are vulnerable to the adverse effects of climate change, yet there is disagreement about what they should do to protect themselves from antic- ipated damages. In particular, it is unclear what the optimal balance is between investments in traditional productive capital (which increases output but is vulner- able to climate change), and investments in adaptive capital (which is unproductive in the absence of climate change, but ‘climate-proofs’ vulnerable capital). We show that, while it is unlikely that the optimal strategy involves no investment in adapta- tion, the scale and composition of optimal investments depends on empirical context. Our application to sub-Saharan Africa suggests, however, that in most contingenc...