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Killer (Heat) Waves: Heat-Related U.S. Deaths could Increase by 150,000 By Century's End Due to Climate Change

Dan Lashof

Posted May 23, 2012

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NRDC released a report today projecting that more than 150,000 additional Americans could die by the end of this century due to excessive heat caused by climate change. This startling conclusion is based on peer-reviewed scientific papers published recently by Dr. Larry Kalkstein and colleagues.

This is the kind of study that should make headlines around the country but is generally ignored when published only in scholarly journals. So NRDC is presenting the information in a more accessible manner, adding calculations of the cumulative additional death toll attributable to projected global warming by mid-century and century’s end (the report, including these additional calculations, was reviewed by Dr. Kalkstein to ensure that we have presented the information accurately)

The “Killer Summer Heat” report gives the results for all 40 cities analyzed in the original papers. The three with the highest number of projected heat-related deaths through the end of the century are: Louisville, KY (19,000 deaths); Detroit (18,000); and Cleveland (17,000). Other cities’ death tolls include:

  • Baltimore: 2,900 deaths
  • Boston: 5,700 deaths
  • Chicago: 6,400 deaths
  • Columbus: 6,000 deaths
  • Denver: 3,500 deaths
  • Los Angeles: 1,200 deaths
  • Minneapolis: 7,500 deaths
  • Philadelphia: 700 deaths
  • Pittsburgh: 1,200 deaths
  • Providence, R.I.: 2,000 deaths
  • St. Louis: 5,600 deaths
  • Washington, D.C.: 3000 deaths.

The projected deaths are based on the widely-used assumption that carbon pollution will steadily increase in the absence of effective new policies, more than doubling the levels seen today by the end of the century.

These findings bring home the fact that global climate change has a number of real life-and-death consequences in our local communities. One of which is that as carbon pollution continues to grow, climate change is only going to increase the number of dangerously hot days each summer, leading to a dramatic increase in the number of lives lost.

Already an average of 1,300 heat-related deaths occur per year due to direct and indirect effects of heat exacerbating life-threatening illnesses, such as heat exhaustion, heat stroke, cardiovascular disease, and kidney disease, according to Dr. Kalkstein's analysis. That estimate comes from analyzing the 40 largest U.S. cities from 1975 through 2004, so it doesn’t account for the impact of the record-setting heat seen more recently. Last summer at least 42 states saw record daytime highs and 49 states saw record high nighttime temperatures, according to NOAA. And last week NOAA reported that the twelve months that ended on April 30th were the warmest twelve months in the United States since reliable record-keeping began in 1895.

To prevent the health impacts of climate change from getting as bad as the “business-as-usual” scenario portrayed in today’s report we need to change business as usual by establishing a comprehensive program to reduce heat-trapping pollution from all sources. The biggest step taken by the Obama administration so far is a set of landmark clean car standards that will cut tailpipe carbon emissions from new vehicles in half by 2025. The EPA also took an important, but limited, step forward recently by setting the first national standards to reduce air pollution from wells that use fracking to stimulate natural gas production.

But there are still no national limits on carbon pollution from power plants—the largest source of global warming pollution in the United States. That will be the subject of public hearings tomorrow on EPA’s proposal to limit carbon pollution from new power plants. Of course, pollution from existing power plants, refineries and other sources will need to be addressed as well.

If you live near Washington, D.C. or Chicago I urge you to attend the hearing and let EPA know that you agree that it’s long past time to end the practice of dumping unlimited amounts of carbon pollution into our atmosphere. EPA’s proposal is an important step toward protecting public health from the consequences of climate change driven by carbon pollution, and more than one million comments have been filed with the agency in support of moving forward. That’s already a record, but we can’t stop now. Let’s blow the record away with another million before the comment period ends on June 25th. Add your voice here.

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meme mineMay 23 2012 08:15 PM

Climate change must be “deadly” to be counted as real. You can’t have a little crisis. Yes they all agree but few endorse any warning of unstoppable warming and death for all. It’s the worst crisis imaginable or it isn’t a crisis. REAL planet lovers rejoice at the good news of the crisis being exaggerated and 26 more years of condemning the voter’s children will leave progressivism out of power for decades.

BSMay 23 2012 09:26 PM


I agree. Hopefully soon all the idealogues who can't even express happiness that warming is ocurring more slowly than they predicted will soon be marginalized. And then perhaps we can get back to real science and real progress. If humans are affecting the climate, we do need to take action. But alarmists who spin and alter the facts don't help matters.

Dr George BlumbergMay 24 2012 05:23 AM

Deaths from excessive heat stress have a large social and structural element and are preventable with good urban planning, social structure and domestic design. It's good to know that the risk of excessive heat may increase, but we should be aware that it is possible to prepare for these events and to prevent unnecessary loss of life.

Stan ScobieMay 24 2012 09:57 AM

Could you give us a link to the NRDC report?

Or maybe it is here and these old eyes cant find it?


Dan LashofMay 24 2012 07:14 PM

Stan--Follow the link from "report" in the first line of the post.

George--Thanks for your comment. We agree. We are calling for cities to address both prevention (by establishing policies to cut carbon pollution and supporting federal standards) and preparedness (to provide early warning, cooling centers, and other interventions to minimize the loss of life during excessive heat events).

Pam BlixtMay 27 2012 05:32 PM

It is problematic that reports cites specific cities when I believe that metropolitan statistical areas (MSA) are most likely the region used instead. For example, where I am from, in Minneapolis, the likely increase will include the 15 counties (with a population of 3 million) of the MSA instead of just the City Of Minneapolis, with a current population of 400,000. While the projected increase is still large, it paints a less alarming portrait.

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