Study explores climate impacts at the local level

Southern U.S. climate change

The southern U.S. will see more negative climate impacts than other areas of the country. Image: Library of Congress

Study explores climate impacts at the local level

By Stephanie Sides

A study published this summer in Science magazine describes the economic impact of climate change on the U.S. over the next 100 years—down to the level of individual counties.

This study predicts negative impacts in the southern U.S. but positive impacts in parts of the Pacific northwest and New England. It concludes that economic damage across six sectors—agriculture, crime, coastal storms, energy, human mortality, and labor—will cost roughly 1.2% of gross domestic product with each degree Celsius increase in temperature.

The study was led by Climate Impact Lab and lead author Solomon Hsiang from UC Berkeley, who teamed up with experts from Rutgers, University of Chicago, Princeton University, the National Bureau of Economic Research and others. The authors integrated national data on how the six sectors respond to short-term weather fluctuations with a set of global climate models to estimate future costs for a range of scenarios.

Of course, these predictions are just based on what we know today—it’s entirely possible that people will find new ways to adapt to climate change that may affect future population growth and migration patterns. But for now, here’s what the study says we can expect.

Poorest counties will experience greatest loss

The damage is expected to disproportionately affect some parts of the country while relatively sparing others. This will transfer even more value to the spared areas, potentially increasing regional economic inequality. The study posits with a 90% likelihood that, by the end of the century, the poorest third of U.S. counties will be likely to suffer losses of 2-20% in county income based on the current level of greenhouse gas emissions.

Increased heat waves and more deaths

These numbers and predictions provide scientific grounding to what might seem intuitive. Places that are already relatively hot, like Florida and Texas, will suffer an increase in heat waves. The study predicts that the resulting deaths will be comparable to the number of people that die in car accidents every year.

Extreme heat can have other serious health consequences: Heat exhaustion and heat stroke, and exacerbation of other conditions like asthma and cardiovascular disease, conditions to which the very old and very young are particularly vulnerable.

Higher energy costs

Rising temperatures are likely to lead to an increase in energy costs because utilities will need to build more extensive infrastructure to support heavier use of air conditioning during the hottest periods. These costs will then be passed on to rate-paying customers.

Change in continental migration pattern

Outdoor workers, such as those in the agricultural and construction industries, will be particularly hard hit. It may become so hot in some places during certain parts of the year that it will be impossible to work outdoors. That will affect workers’ ability to earn a livelihood and industrial productivity, and may cause people to escape the heat in historically large numbers by moving to more temperate northern climes.

Effects on infrastructure

Prolonged exposure to extreme heat can also affect transportation and infrastructure. Highways and railroads can buckleand the accompanying lower air density means aircraft must work harder to take off. Because aircraft are not rated for safety above 118 degrees Fahrenheit, they have to be grounded until temperatures cool. This situation is no longer theoretical: It affected nearly 50 flights in Phoenix this summer.

Climate change in your hometown

Speaking of extreme heat, you can now gain a glimpse of how your area will be affected by heat in the future. An interactive website by Climate Central tells you how the number of days above summer temperature thresholds will change throughout the rest of the century. These thresholds vary with the city: for San Diego, it’s 95 degrees, for Phoenix, it’s 115. Just enter the name of your town—you’ll be shocked by the dramatic change over time.

My hometown of Encinitas, Calif., should expect 74 more days above 95 degrees Fahrenheit by 2100. It only rarely gets that hot now. You can also simulate what will happen with moderate or extreme emission cuts. In the case of my town, that brings the number of days with extreme heat down to 57 and 42 days, respectively. These numbers represent dramatic change in their own right.

Now that the average citizen can access information about climate impacts on specific areas of our country, it’s important that Congress have that information, too. Take a look at the study and the Climate Central website to learn how your city or congressional district could be impacted by climate change in the coming years, and consider sharing that information with your representative or Senators during Congressional Education Day this November. It’s time for bold, effective legislation to address climate change, and this localized data could help your message really hit home.

Stephanie Sides
Stephanie Sides is a freelance writer who works primarily with academics in science, medicine, and engineering.