Perhaps the biggest single question about climate change is whether people will have enough to eat in coming decades.
We have had two huge spikes in global food prices in five years that were driven largely by chaotic weather. And this year we may be in the early stages of a third big jump. Droughts and heat waves have damaged crops in many producing countries this year, including the United States and India.
If any of that sounds alarmist, recall what has already happened because of the price spikes of recent years. In 2008, food riots broke out in more than 20 countries, and the government of Haiti fell as a result of the unrest. The second price spike, in 2011, apparently played a role in the social discontent that led to the revolutions in the Arab world.