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And we’re only beginning to appreciate all the consequences

Extreme temperatures — highs above 100 and as much as 120 degrees or more — are occurring with increasing intensity, frequency, and duration due to climate change. We have yet to come to terms with the consequences, despite the fact more people die from extreme heat than from all other natural disasters combined. If (as is the case) some places are too hot for human survival, you can be sure heat is changing the planet and our lives in many other ways.

When I first started working on climate change several decades ago, discussion of warmer temperatures often focused on changes in averages. On this basis, for example, it was (and still) is often said the climate in Washington, D.C. would become more like that of Memphis and that of Boston more like that of New York — hardly disturbing (unless you run a ski resort!). Indeed, the first scientist to model the expected change in global average temperature with a doubling of carbon dioxide, Svante Arrhenius, thought the prospect for warmer winters in his native Sweden was a good thing. As recently as 2007, a feature article in The Atlantic was titled “Global Warming: Who Loses — and Who Wins?”, asserting climate change would bring some regions “tremendous benefits” from longer growing seasons. It’s now evident even Russia, one of the alleged “winners”, has much to lose from climate change.

The focus on predicted modest increases in average temperatures did not convey the true meaning of climate change including heat extremes in places totally unprepared. A good example is the heat wave in the Pacific Northwest in June 2021. Places like Portland, Oregon where most residents previously had no need for air conditioning, experienced an all-time record temperature of 116 degrees. The most direct consequences of these heat extremes, as discussed in previous Medium posts, are increasingly in the news and weather reports:

1. Heat kills and sickens and it’s getting worse. In some places temperatures are approaching the limits of human survivability. While cold has historically caused far more deaths than heat worldwide, this is changing due to climate change. Recent research strongly indicates the human body is more sensitive to the combination of heat and humidity than previously thought.

2. Heat results in economic losses in the many billions, on the order of $100 billion a year in the U.S. alone and up to $500 billion a year by 2050. The greatest source of loss is the diminished productivity of workers outdoors — still about a fifth of the population (farmers, construction workers, landscapers, delivery drivers, etc.)

3. Heat is a major contributor to other natural disasters. Including wildfires, droughts, sandstorms, and severe air pollution events. In addition to providing more energy for hurricanes, warmer air can hold more moisture, which means more intense rainfall events and a greater probability of flooding.

Yet understanding the many ways extreme temperatures will impact our lives is only gradually becoming clear. Consider:

1. Crop losses due to extreme heat are increasing in severity and leading to famine. In India, brutal heat waves have killed dozens and cut food production by about 30 percent. These scorching temperatures were made at least 30 times as likely because of human-caused climate change In response, India announced in May it would shut down all grain exports, staving off famine in the country but threatening starvation abroad.

2. Heat extremes and famine are creating what has been termed the Great Climate Migration. It’s expected almost 20 percent of the global population will be in areas exposed to intolerable heat by 2070. Millions will be forced to seek cooler climes.

3. The poorest, frequently including minorities, will be most vulnerable, exacerbating issues of global inequality. Environmental health expert Tarik Benmarhnia observes, “Think about who contributed to climate change over the last century, and who is seeing the most consequences today, and you see it is not fair. There is a huge environmental injustice in term of who is suffering the heat-related mortality caused by anthropogenic climate change.”

4. Air conditioning is both a cause and solution to extreme temperatures. Most of the 3 billion people living in regions with high temperatures lack air conditioners, but with rising incomes and the need to keep cool its projected by 2050 more than a billion new units may be installed. The power required for all this equipment could more than triple by 2050, consuming as much electricity as all of China and India today. Generating this additional power has been described as a “veritable carbon time bomb.” Sustainable cooling based on much more energy efficient technologies is critical and urgent.

5. Warming the air is warming the ocean resulting in thermal expansion, melting sea ice, and disappearing beaches. Warmer ocean temperatures are also creating more intense hurricanes of longer duration and changing ocean currents with a significant role in weather patterns. This has many unpredictable consequences, e.g., likely a factor in the polar vortex that left thousands in Texas without power for days.

6. Heat extremes are expected to cause a significant loss of biodiversity, already occurring. A major study found at moderate levels (i.e., 1–2 °C) of temperature increase a significant decrease of original biodiversity is projected. Fires in California now threaten hundreds of sequoia trees, among the largest and oldest living things on the planet.

7. Roads, rails, power generation and transmission, and other infrastructure will operate much less efficiently, adversely impacting travel and sometimes shutting off the power grid as is now a threat in Texas.

8. Some crops have temperature limits and will need to be replaced by new varieties. Production of staples including wheat and corn may decline significantly within a decade. Coffee and tea, beer and wine are among many highly valued climate sensitive crops; alternative varieties may cost more and not taste as good.

Coming to terms with the reality of extreme heat is a challenge the world is only gradually beginning to face. Given the diverse and complex range of cooling needs, there is no single solution. Air conditioner manufacturers must make much more climate friendly equipment; toward this end, a global cooling prize was awarded last year to two companies based on prototypes for equipment with a 5-fold improvement over current designs.

Cities will need to have heat officers, a position recently created in Miami, Florida. Proposed legislation in California would create an early warning system for heatwaves. Weather reports may soon include heat rankings and naming of extreme heat events to convey the danger.

As July begins, days in excess of 100 degrees are already frequent in many parts of the U.S. Climate change and extreme temperatures is no longer some distant concern — the time to act is now.

A final recommendation: the August 2022 issue of Consumer Reports includes useful tips on dealing with high temperatures, “CR’s Ultimate Heat Survival Guide” including ratings of air conditioners.

Alan Miller is a former climate change officer in the International Finance Corporation (2003–13) and climate change team leader, Global Environment Facility (1997–2003). Besides other engagements, Alan is an active editor for Climate Conscious submissions on Medium.