By Deborah Zabarenko
WASHINGTON (Reuters) - Killer heat fueled by climate change could cause an additional 150,000 deaths this century in the biggest U.S. cities if no steps are taken to curb carbon emissions and improve emergency services, according to a new report.
The three cities with the highest projected heat death tolls are Louisville, with an estimated 19,000 heat-related fatalities by 2099; Detroit, with 17,900, and Cleveland, with 16,600, the Natural Resources Defense Council found in its analysis of peer-reviewed data, released on Wednesday.
Concentrated populations of poor people without access to air conditioning are expected to contribute to the rising death tolls.
Thousands of additional heat deaths were also projected by century's end for Baltimore, Boston, Chicago, Columbus, Denver, Los Angeles, Minneapolis, Pittsburgh, Providence, St. Louis and Washington, D.C., the report said.
June, July and August are expected to see above-normal temperatures over most of the contiguous United States, from inland California to New Jersey, and from as far north as Idaho and Wyoming to Texas, Florida and the desert Southwest, the National Oceanic and Atmospheric Administration said in a May 17 forecast.
The last 12 months, from May 2011 to April 2012, were the warmest in the contiguous United States since modern record-keeping began; last month was the hottest April on record for the Northern Hemisphere.
These figures show climate change is already being powerfully felt, and more dangerously hot summer days are in prospect under a business-as-usual scenario, said Dan Lashof, director of NRDC's climate and clean air program.
NRDC, which with other environmental groups has pushed for curbs on U.S. emissions of heat-trapping carbon dioxide, is backing a plan by the U.S. Environmental Protection Agency to limit carbon emissions from new U.S. power plants. The EPA is holding public hearings on Thursday on the dangers of carbon pollution from power plants. The EPA's plan is unlikely to go into effect until after this year's election campaign.
The deadliest days are those designated Excessive Heat Events (EHEs), often in urban areas where air conditioning is scarce or unreliable, with sizable poor populations and municipal services unprepared for large numbers of people sickened by the heat, Larry Kalkstein, a University of Miami professor who wrote two studies on the subject.
One was published in the American Meteorological Society's journal Weather, Climate and Society; the other in the journal Natural Hazards. Both were peer-reviewed.
There could be five times the number of Excessive Heat Event days by mid-century and eight times that number by the end of the century, Kalkstein said in a telephone briefing. The current average number of EHEs per year is 233; by mid-century it could be 1,342, and by 2100, it could be 1,913.
The full report is available online at http://www.nrdc.org/globalwarming/killer-heat/ .
The most disastrous heat waves, like the one that killed more than 700 people in the Chicago area in 1995, come when high heat lasts beyond two days in urban areas without plans to reach the most vulnerable populations: the elderly, the obese and those on medication.
Kalkstein praised Chicago for improving its heat warning system, emergency services and cooling centers since then. He also said Philadelphia and Seattle had put measures in place to lessen the risk from excessive heat days.
The studies considered cities because that is where two-thirds of the U.S. population lives, Lashof said. There is some evidence that heat deaths in rural areas will also rise, but that is harder to document, he said.
U.S. cities aren't the only ones bracing for the impacts of extreme weather. Ten Asian cities are assessing how ready they are to deal with floods, droughts, heat waves and other expected results of climate change.
The Asian Cities Climate Change Resilience Network is working in 10 cities in India, Indonesia, Thailand and Vietnam to figure out technical indicators -- such as the capacity of water systems, sewage and waste-water services and the size of deforested areas upstream from urban areas -- to help plan to protect city residents. More information on the plan is available at http://www.acccrn.org/ .
(Reporting by Deborah Zabarenko, Environment Correspondent; Editing by Cynthia Osterman)