SOURCE: Scientific American

DATE: March 1, 2019

SNIP: Warming temperatures do not only threaten lives directly. They also cause billions of hours of lost labor, enhance conditions for the spread of infectious diseases and reduce crop yields, according to a recent report.

The report, published last December in the Lancet, represents the latest findings of the Lancet Countdown—a coalition of international research organizations collaborating with the World Health Organization and the World Meteorological Organization. The group tracks the health impacts of—and government responses to—climate change.

“It affects everyone around the world—every single person, every single population. No country is immune,” says Nick Watts, executive director of the Lancet Countdown and one of many co-authors of the report. “We’ve been seeing these impacts for some time now.”

The report found that millions of people worldwide are vulnerable to heat-related disease and death and that populations in Europe and the eastern Mediterranean are especially susceptible—most likely because they have more elderly people living in urban areas. Adults older than 65 are particularly at risk, as are those with chronic illnesses such as heart disease or diabetes. Places where humans tend to live are exposed to an average temperature change that is more than twice the global average—0.8 versus 0.3 degree Celsius (graphic). There were 157 million more “heat wave exposure events” (one heat wave experienced by one person) in 2017 than in 2000. Compared with 1986 to 2005, each person was exposed to, on average, 1.4 more days of heat wave per year from 2000 to 2017. That may not seem like a lot, but as Watts notes, “someone who is 75 and suffers from kidney disease can probably survive three to four days of heat wave but not five or six.”

Sweltering temperatures also affect productivity. A staggering 153 billion hours of labor—80 percent of them in agriculture—were lost to excessive heat in 2017, the new report found, with the most vulnerable areas being in India, Southeast Asia, sub-Saharan Africa and South America.

Then there are indirect effects. For example, warmer temperatures have increased the geographical ranges of organisms that spread dengue fever, malaria and cholera.

Climate change also threatens food security. Our planet still produces more than enough food for the world, but 30 countries have seen crop yields decline as a result of extreme weather, the report found.