Heat waves in Eastern US will become deadlier, study says
Wu J, Y Zhou, Y
Gao, JS Fu, BA Johnson, C Huang, YM Kim, Yang Liu. 2013. Estimation and
uncertainty analysis of impacts of future heat waves on mortality in the
Eastern United States. DOI:10.1289/ehp.1306670
Synopsis by Brian
Bienkowski in Environmental
Health News
 |
| The 2011 heat wave in the Eastern U.S. killed dozens and shattered temperature records |
Heat waves will kill about
10 times more people in the Eastern United States in 45 years than they did at
the turn of this century, according to a new projection from researchers. The
study builds on previous research that predicts as climate change spurs more
frequent heat waves, there will be more heat-related deaths.
Heat waves
will kill about 10 times more people in the Eastern United States in 45 years
than they did at the turn of this century, according to a new projection from researchers.
"Estimates
suggest that mortality risks from future heat waves may be an order of
magnitude higher than in 2002-2004,” says the study, which was published online
this week in the journal Environmental Health Perspectives.
The
researchers used two climate change projections for the Eastern third of the
United States. Both assume that emissions will increase, but at different
rates. One scenario projects “low-medium” greenhouse gas emissions and one
projects a “more extreme” scenario, similar to today’s rate. Under the
“low-medium” scenario, heat wave-related deaths would increase by 1,403 per
year compared with 3,556 under the more dire projection, according to the
study.
An
estimated 187 people in the Eastern United States died of causes related to
heat waves per year during 2002-2004. Nationwide, about 660 people die
each year from heat waves,
according to the U.S. Centers for Disease Control and Prevention.
The large
disparity between the projections suggests “curtailing emission will have a
great impact on the reduction of heat wave mortality in the future,” wrote the
authors, led by Emory University environmental health scientists.
The
scientists found that heat waves will be 3.5 to 6.4 times more frequent from
2057 to 2059 compared with 2002 to 2004.
Some
places will have it worse than others: 10.4 percent of the 1,700 counties in
the study are projected to have more than four heat waves per year under the
lower emissions scenario, and 26.5 percent would have more than four heat waves
per year under the increased emissions scenario.
Southern
states such as Florida, Georgia and Louisiana, and those on the coast, such as
Massachusetts, New York and New Jersey, would have the biggest jump in deaths,
according to the study.
“Effective
mitigation and adaptation measures will be crucial to reduce the potential for
catastrophic outcomes, particularly in the most vulnerable geographic regions,”
the authors wrote.
Air
temperature is projected to increase between 3.2 and 11.52 degrees Fahrenheit
over the next 90 years, increasing the frequency, intensity and duration of
U.S. heat waves, according to the Intergovernmental Panel on Climate Change.
Heat waves cause spikes in body temperature, which can cause brain and organ
damage, and, in severe cases, death. The elderly, poor, children and outdoor
workers are most at risk.
The study
is limited since the Eastern United States is largely urban. City temperatures
are generally higher, driving up projected deaths. In addition, the researchers
didn’t look at non-heat wave days that could be hot enough to cause deaths.
For the
study, the scientists used scenarios developed by the IPCC, one “low-medium
scenario of climate change that assumes moderate emissions and use of a range
of technologies and strategies for reducing greenhouse gas emissions, and the
more extreme RCP8.5 scenario, which assumes fossil fuel intensive energy
consumption with increasing greenhouse gas emissions,” similar to today’s rate.