To the editor:
Thom Krystofiak’s admonition to remember the challenges of climate crisis as we respond to the coronavirus left out one important point: pandemics are in fact caused and/or aggravated by key features of the climate crisis. Points below are sourced from an article in a March issue of The Nation by Sonia Shah, science journalist and author of “Pandemic.”
Since 1940, hundreds of microbial pathogens (HIV, Ebola, Zika, many novel coronaviruses) have emerged. 60 percent originate in the bodies of animals. More than two-thirds of those have spread from wildlife, where most live harmlessly in the animals’ bodies. Habitat destruction forces wild species to cram into fragments of territory, bringing them into repeated contact with humans, allowing their microbes to cross over into our bodies.
According to a 2017 study, Ebola outbreaks, linked to several species of bats, are more likely to occur in recently deforested areas of Africa - forcing bats to roost in trees in backyards and farms, exposing people who eat the fruit of the trees, hunt the bats, etc. Many pathogens have slipped into human populations via similar exposure.
Malaria and other mosquito-borne disease outbreaks are linked to the felling of forests, causing water and sediment to flow along ground newly open to sunlight, creating puddles where mosquitoes breed. A study in 12 countries found that mosquito species carrying human pathogens are twice as common in deforested areas as in intact forests.
The expansion of suburbs into U.S. forests increases the risk of tick-borne diseases by driving out creatures like opossums, which help control tick populations, while improving conditions for white-footed mice and deer, which don’t. Seven new tick-borne pathogens have emerged since Lyme disease was identified in 1975.
Areas of wild habitat totaling roughly the size of Africa have been razed to raise animals for slaughter, some of which are sold in wet markets where animals that would rarely encounter one another in nature are caged close together, allowing microbes to jump from one species to the next. This process begat the coronavirus that caused the 2002-2003 SARS epidemic, and possibly also today’s coronavirus.
Avian influenza viruses, including H5N1, rampage in factory farms crowded with captive chickens. Cattle in CAFOs produce excreta collected in unlined cesspools, spreading Shiga-toxin-producing Escherichia coli, which can live harmlessly in the guts of cattle, but infects some 90,000 Americans every year with bloody diarrhea, fever, acute kidney failure, and sometimes even death.
Most of our current and potential pandemics are directly or indirectly related to the larger picture of rapidly unfolding climate crisis, and cannot be effectively addressed apart from it. We need to not only discontinue using fossil fuels, but also restructure our large-scale approaches to energy, habitat and agriculture. It’s a huge, but not impossible, challenge. Agricultural experts, for example, now tell us we can feed humanity in ways that produce higher yields of healthier food while sequestering carbon back into the soil. “Grassroots Rising” by Ronnie Cummins provides an extensive discussion of this important topic.
- Fred and Betty Krueger, Fairfield