Climate adaptation means tough decisions

James K. Boyce in the Journal-Star (Nebraska):At the latest round of international climate talks this month in Lima, Peru, melting glaciers in the Andes and recent droughts provided a fitting backdrop for the negotiators’ recognition that it is too late to prevent climate change, no matter how fast we ultimately act to limit it. They now confront an issue that many had hoped to avoid: adaptation.

Adapting to climate change will carry a high price tag. Sea walls are needed to protect coastal areas against floods, such as those in the New York area when Superstorm Sandy struck in 2012. We need early-warning and evacuation systems to protect against human tragedies, such as those caused by Typhoon Haiyan in the Philippines in 2013 and by Hurricane Katrina in New Orleans in 2005.

Cooling centers and emergency services must be created to cope with heat waves, such as the one that killed 70,000 in Europe in 2003. Water projects are needed to protect farmers and herders from extreme droughts, such as the one that gripped the Horn of Africa in 2011. Large-scale replanting of forests with new species will be needed to keep pace as temperature gradients shift toward the poles.

Because adaptation won’t come cheap, we must decide which investments are worth the cost.

A thought experiment illustrates the choices we face. Imagine that without major new investments in adaptation, climate change will cause world incomes to fall in the next two decades by 25 percent across the board, with everyone’s income going down, from the poorest farmworker in Bangladesh to the wealthiest real estate baron in Manhattan. Adaptation can cushion some but not all of these losses. What should be our priority: reduce losses for the farmworker or the baron?

For the farmworker, and a billion others in the world who live on about $1 a day, this 25 percent income loss will be a disaster, perhaps the difference between life and death. Yet in dollars, the loss is just 25 cents a day. For the land baron and other “one-percenters” in the U.S. with average incomes of about $2,000 a day, the 25 percent income loss would be a matter of regret, not survival. He’ll find a way to get by on $1,500 a day. In human terms, the baron’s loss pales compared with that of the farmworker. But in dollar terms, it’s 2,000 times larger....

A sea wall in Jersey, released into the public domain by Man vyi