In the U.S., yields from four major crops will drop by as much as 40% on average by the end of the century due to a warming climate, according to a recent study in the journal Science. And while reducing carbon emissions to minimize future warming is by far the most cost-effective means for avoiding this outcome, it is increasingly clear that some amount of adaptation will also be needed.
In the agricultural sector, that likely means significant crop migration over the long term—areas in the northern U.S. and southern Canada are likely to become more important sources of grain production, while yields decline in the south and middle of the country due to higher summer temperatures. This transition will take time and require significant investment, to say nothing of the distributional consequences for farmers who can’t simply move their land northward. Meanwhile, many regions of the country will increasingly rely on expanded irrigation to produce the same crops at similar levels.
America’s farmers already account for 80% of our consumptive water use. To make good use of scarce water resources in a climate-stressed future, it will be critical to ensure that water flows to the highest-value applications. Economists and other researchers have pointed out over and over again that markets offer the most effective means for solving these kinds of problems.
But for markets to work, we need to let them.
Unfortunately, the markets for water are failing in many U.S. states today, especially in the West, due to a web of poorly defined and unevenly enforced property rights that have given rise to misaligned incentives and uncertainty.