Heat Waves — In Red and Black | Reasons for a Dividend-Based Carbon Tax, Part 3: Heat that Kills

William Rau


Kim Stanley Robinson opens his climate fiction opus, “The Ministry for the Future,” in the year 2025 with a brutal heat wave spreading across India. Heat and humidity approach the survival limit for humans. Then, the grid goes down across much of the country. No air conditioning for those who can afford it exactly when air temperature exceeds 107°F and humidity reaches 60%. Finally, those with backup generators run out of fuel or have their generators seized by armed marauders. Even the wealthy lose their climate protection and succumb to the killing heat of an angry sun.

In some Indian towns every human and mammal dies. With no one left to bury the dead, the pervasive stench of rotting flesh and the ubiquitous presence of vultures signals a climate holocaust. Twenty million Indians perish. Unbelievable? Is Robinson’s tale more far-fetched fiction than climate science? Consider a few facts.

First, humid heat in some hot spots now reach levels that will kill Olympic athletes. This level is a “wet bulb” temperature of 35° Celsius (C). A wet bulb temperature combines heat, humidity, wind speed, solar radiation and cloud cover. When wet bulb temperatures reach 35°C, “even a strong, physically fit person resting in the shade with no clothes and unlimited access to drinking water would die within hours” (Earth Institute 2020).

Once thought a problem in the distant future, better measurement is now finding places, including some along the U.S. Gulf Coast, that briefly reach these temperatures today. As importantly, causalities begin with wet bulb temperatures as “low” as 27°C. Since 1979, the frequency of wet bulb temperatures between 27°C and 35°C has doubled and will continue to increase in frequency, areal expanse and number of people affected.

Second, power systems turn brittle and often break during lengthy periods of extreme heat. The power capacity of transformers, transmission lines and power plants decline as temperatures soar. As climbing temperatures send electricity demand through the roof, power output from thermoelectric power plants declines significantly, some plants trip offline, and others are idled due to lack of cooling water. The end result can be the kind of rolling blackouts that deprived over two million Californians of power in 2019.

Third, scientists predict heat waves will become larger, hotter and more frequent as this century unfolds. If we continue generating large quantities of greenhouse gases, the fraction of the world’s population facing 20 or more days of lethal heat per year will increase from 30% today to 74% in 2100. Moreover, the number of potentially lethal-heat days will also increase: 60 per year in “more temperate” latitudes and almost every day in the humid tropics (Mora 2017).

More than one billion of India’s 1.38 billion people currently lack air conditioning. What happens to them during a lengthy heat wave with wet bulb temperatures reaching 33°C?

Dividend-based carbon taxes will not prevent future heat waves, but they can help to reduce the severity, areal spread and days of angry sun headed our way.


Crosby, Ian, et al. 2019. Chilling Prospects: Providing Sustainable Cooling for All. Sustainable Energy for All; https://www.seforall.org/sites/default/files/SEforALL_CoolingForAll-Report.pdf

Dzieza, Josh. 2017 (Sep 14). The race against heat: How do you cool 7.5 billion people on a warming planet? The Verge; https://www.theverge.com/2017/9/14/16290934/india-air-conditioner-cooler-design-climate-change-cept-symphony

Earth Institute. 2020 (May 8). Potentially fatal combinations of humidity and heat are emerging across the globe. U.S. Gulf Coast among regions hit with conditions not expected for decades. Columbia University; https://www.sciencedaily.com/releases/2020/05/200508145333.htm

Lavelle, Marianne. 2017 (Jun 19). Deadly Heat Waves Could Endanger 74% of Mankind by 2100, Study Says. Inside Climate News; https://insideclimatenews.org/news/19062017/heat-waves-world-population-risk-endangered-climate-change-study/

Mora, Camilo, et al. 2017. Global risk of deadly heat. Nature Climate Change; https://www.researchgate.net/publication/318173438_Global_risk_of_deadly_heat

Raymond, Colin, et al. 2020 (May 8). The emergence of heat and humidity too severe for human tolerance. Science Advances; https://advances.sciencemag.org/content/suppl/2020/05/04/6.19.eaaw1838.DC1

2 comments for “Heat Waves — In Red and Black | Reasons for a Dividend-Based Carbon Tax, Part 3: Heat that Kills

  1. Abhaya Thiele
    January 28, 2021 at 6:16 am

    Thank you for this important article.
    In future articles, might you please put the Fahrenheit temperature in parentheses next to the Celsius temperature? That way U.S. readers will have a better understanding of the heat impacts you are describing. (Sadly, we in the U.S. still are not taught the metric system.). And, too, thank you for using the term, “ Dividend-based carbon taxes,” This is a term that is not yet widely used in the U.S., and I hope it can become better known as it will be more politically palatable than “a carbon tax.” Again, thank you.

  2. Jim Davis
    January 28, 2021 at 8:14 am

    Excellent article that uses scientific information to make a strong argument: the time has come to act on climate change.

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