Hot enough for you? Deadly heat waves likely to get worse
Individual daily heat records are being matched and shattered across the country and around the world. And new research predicts that by the year 2100, climate change means that such heat could expose three-fourths of the world’s population to deadly temperatures.
Temperatures in the Southwest are climbing to more than 120 degrees—it was so hot in Phoenix last week that some planes weren’t able to take off or land. Now, weather is not climate, and one day’s soaring heat is just that—one day. But what used to be a few-days-a-summer event of horrific heat in some locations will become more common and have deadly consequences, according to a new study from Nature Climate Change.
An international research team did a global analysis of “lethal heat events,” or occasions when extreme heat caused deaths, looking at nearly 2,000 academic papers published between 1980 and 2014. The researchers identified “783 cases of excess human mortality associated with heat from 164 cities in 36 countries.” According to the researchers’ abstract:
Based on the climatic conditions of those lethal heat events, we identified a global threshold beyond which daily mean surface air temperature and relative humidity become deadly. Around 30% of the world’s population is currently exposed to climatic conditions exceeding this deadly threshold for at least 20 days a year. … An increasing threat to human life from excess heat now seems almost inevitable, but will be greatly aggravated if greenhouse gases are not considerably reduced.
Here’s the researchers’ frightening forecast: If climate change continues along current trends, without a lowering of carbon emissions, that 30 percent figure will rise to 74 percent of the global population by the year 2100. In other words, three in four people could face the threat of dying from extreme heat by the end of the century.
Even with drastic carbon emission cutbacks, 48 percent of the world’s population will still face risks from deadly heat waves because of the amount of heat-trapping gases that already have accumulated in the atmosphere.
“The human body can only function within a narrow range of core body temperatures around 37°C,” or 98.6 degrees Fahrenheit, wrote biogeographer Camilo Mora, head of the multi-person research team that produced the Nature Climate Change study. “Heat waves pose a considerable risk to human life because hot weather, aggravated with high humidity, can raise body temperature, leading to life-threatening conditions.”
National Geographic explains the research.
“Lethal heat waves are very common. I don’t know why we as a society are not more concerned about the dangers,” says Camilo Mora of the University of Hawaii at Manoa, the study’s lead author. “The 2003 European heat wave killed approximately 70,000 people—that’s more than 20 times the number of people who died in the September 11 attacks.”
Dangerous heat waves are far more common than anyone realized, killing people in more than 60 different parts of the world every year. Notable deadly heat waves include the 2010 Moscow event that killed at least 10,000 people and the 1995 Chicago heat wave, where 700 people died of heat-related causes.
(A personal note: I remember vividly the 1995 Chicago heat wave. Temperatures hovered around 105 degrees for several days in a row. A trip to a community swimming pool brought no relief, as the usually cool water turned tepid in the baking heat. People without air conditioning were urged to go to city cooling centers. Drivers were advised to stay off the roads to avoid creating even higher ozone-alert levels. There were “brown-outs”—loss of electricity during certain times of the day in certain neighborhoods—exactly the same thing more temperate areas of California are going through right now. And the death toll from the deadly heat rose daily.)
Back to the study:
“Our attitude towards the environment has been so reckless that we are running out of good choices for the future,” says Mora of the University of Hawaii.
“For heat waves, our options are now between bad or terrible,” he adds. “Many people around the world are already paying the ultimate price of heat waves.”
An equally frightening new study in Science Advances, the journal of the American Association for the Advancement of Science, concentrates on heat waves in India but extrapolates its conclusions to show the effect of rising temperatures worldwide.
The impact of these heat waves on human and natural systems include decreased air quality, diminished crop yields, increased energy consumption, increased evapotranspiration, intensification of droughts, and—perhaps most concerning of all—direct effects on human health. Heat stress during periods of high temperatures may also exacerbate health problems, such as cardiovascular and respiratory diseases, and cause life-threatening crises. Certain segments of the population, such as the young, elderly, and poor, may therefore be especially susceptible to this health impact due to existing health conditions and lack of basic resources, such as clean drinking water, shelter, access to air conditioning, and health care. Populations without central air conditioning tend to have higher heat-related mortality rates. …
Our results suggest that even moderate and practically unavoidable increases in mean temperatures, such as 0.5°C, may lead to large increases in heat-related mortality, unless measures are taken to substantially improve the resilience of vulnerable populations.
The Nature Climate Change study is gaining widespread attention, and other scientists are agreeing with its conclusions. As Inside Climate News says in its report on the research:
By the time children born today are in their 80s, New York will have 50 days per year with temperatures and humidity exceeding the threshold beyond which people have previously died due to hyperthermia, if no steps are taken to curb greenhouse gas emissions. Sydney would face 20 deadly heat days a year by 2100, and Los Angeles would face 30 under a “business as usual” scenario. The study notes that the consequences of exposure to deadly climatic conditions will be aggravated by an aging population, since elderly people are more vulnerable to heat mortality, and by increasing urbanization, because of the heat-trapping effect of asphalt surfaces, building materials, and reduced vegetation.
For Orlando and Houston, deadly heat would last the entire summer by 2100 without steps to reduce greenhouse gas emissions, the study projects. Indeed, even though the degree of future warming is projected to be greater in temperate zones and at the poles, the greatest risk to people from deadly heat events will be at zones closer to the equator, because of the additional impact of humidity. …
The study bolsters previous research projecting increasing risk to humanity due to heat waves because of climate change.
It’s not just in the United States—look at the extreme heat around the world. The World Meteorological Association reports that this year’s heat waves have arrived “unusually early.” The United Nations News Centre reports record-high heat in May and June in Europe, the Middle East, North Africa, and the U.S. It’s no surprise that many leaving the Middle East are being called “climate refugees” or “environmental migrants.” Military leaders in the U.S. and elsewhere are already saying that climate change could cause a refugee crisis on an “unimaginable scale.”
The big difference is that many places in the U.S. have air conditioning, which, while providing relief, also adds to greenhouse gas emissions. Many places in Europe don’t, especially the further north you go. As Sandy Anderson, an American friend who has lived in Paris most of her life, described it:
A few métros have AC, some cinemas, a few museums (for the art), but the people get to take advantage of it. Most office buildings and stores don’t. No private residences that I know of—even in the south, where it’s hotter more often. It’s been so hot for the last few days that ozone is getting high, and older diesel-burning cars won’t be allowed on the roads tomorrow—which impacts more people here than it would in the U.S. They’re giving a special one-day commuter ticket for the subway tomorrow and making the public bikes and some of the public cars free. Air temp was 98°F today, and with humidity factored in, 107°F. That’s HOT for a big city.
Here are examples of the extreme temperatures around the world and their consequences:
- In recent weeks, dozens have died in India and Pakistan’s current heat wave. Temperatures spiked to a record 128 degrees F (53.5 degrees C).
- A wildfire in Portugal in the forested Pedrógão Grande region northeast of Lisbon has killed at least 62 people. Temperatures there of 104 F (40 C) and above contributed to the wildfires.
- The southern United Kingdom is experiencing temperatures in the 90s (34 C)—the hottest days in 40 years. The heat is causing roads to melt, as car tires were “literally ripping the tarmac off the road.”
“Heat is recognized as the most deadly form of extreme weather—more deadly than hurricanes, tornadoes, and floods,” wrote Chicago meteorologist and climate expert Tom Skilling on his Facebook page.
The high number of heat-related flight cancellations in Phoenix was unprecedented. A story in Forbes, also quoting Business Insider, explains the science of how high temperatures can stop air travel.
Believe it or not, it is unsafe to operate many of the airplanes currently in use by major airlines when temperatures are this hot, and science explains why. …
Hot air is less dense. This affects the output of the engines as well as aerodynamic capabilities, increasing the required runway distance and reducing climb performance. Therefore the amount of passengers and cargo a plane can carry are often restricted when temps are very high … How much so depends on the temperature, airport elevation and the length of the available runways. And getting off the ground is only part of it: once airborne, planes have to meet specific, engine-out climb criterion, so nearby obstructions like hills and towers are another complication.
The Arizona Republic reported that nearly 50 regional flights were canceled as mercury neared 120 degrees. The smaller planes used by American Airlines’ American Eagle regional flights, the Bombardier CRJ aircraft, have a maximum operating temperature of 118 degrees. Larger planes, such as those made by Boeing and Airbus, have maximum operating temperatures of 126 and 127 degrees. At the same time, record-tying temperatures in Las Vegas (117) were enough to cancel or delay flights.
Such inconveniences as flight cancellations might drive home the point that global warming is real. As Stephen Colbert said on The Late Show: “Maybe what will finally convince climate skeptics will be a layover in Phoenix.”
Obviously, there will be no help on climate issues from the Trump administration, which has decided to pull the U.S. out of the Paris climate agreement. Energy Secretary Rick Perry denies that man-made carbon dioxide emissions are the primary cause of climate change. “Most likely the primary control knob is the ocean waters and this environment that we live in,” he said. Whatever the heck that is supposed to mean.
Of course, EPA Administrator Scott Pruitt is also a climate denier.
“I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact, so no, I would not agree that it’s a primary contributor to the global warming that we see,” he told CNBC’s “Squawk Box.”
Perry’s and Pruitt’s views are at odds with nearly everyone in the scientific community and the conclusions of NASA and the National Oceanic and Atmospheric Administration, which point out that 2016 was the warmest year on record worldwide. The average global surface temperatures over land and sea in the first five months of 2017 are the second highest on record.
Both the Nature Climate Change and the Science Advances studies were done either at public universities or with public funds. With the Trump administration purging scientists from the EPA’s scientific advisory board and proposing to slash research money and funds for the EPA in general, another question becomes: Who’s going to do this important research in the future?
Originally posted on Daily Kos on June 25, 2017.