When something as unprecedented and disruptive as the COVID-19 pandemic strikes, forcing everyone into quarantine and taking countless lives, it’s only natural to want to assign blame. Well, scientific consensus says that in this case — and in the cases of SARS, MERS, Ebola, Swine Flu, Tuberculosis, Tapeworms, Avian Flu, HIV, West Nile Virus, and countless other diseases that have jumped from animals to humans — biodiversity and habitat loss, along with wildlife trade, are the overwhelming culprits.
Over the summer, the United Nations Environment Program (UNEP) released a report that estimates that zoonotic diseases are responsible for 75% of emerging infectious diseases globally, of which COVID-19 is only the latest example. And the number of emerging diseases is only expected to grow. To minimize the risk of future pandemics, UNEP’s report suggests reimagining the human relationship with nature by taking a number of steps, including, but not limited to, better protecting biodiversity and ending the wildlife trade.
Already, the number of emerging infectious disease outbreaks has risen dramatically over the past few decades. (It’s more than tripled every decade since the 1980s.) And most of those diseases originated from animals – wild animals in particular. Why? When the original host species of a disease recedes or dies out — often due to human activities that shrink or fragment natural habitats — that disease can seek a new host by jumping between species.
Clearing forests and changing land also contribute to crowding and increased contact between humans, domestic animals, and wildlife, providing the ideal conditions for infectious diseases to spread. Both Ebola and HIV, for example, emerged in regions where deforestation was occurring. Plus, as habitats are destroyed, the composition of species within ecosystems is often altered. It’s been observed that when animals at the top of the food chain go extinct, their place is filled by animals at the bottom — often those species carrying the most pathogens.
Wildlife markets are another example of humans infringing on and exploiting their environment, and they can be an incubator for the spread of zoonotic disease. When numerous, often stressed and ill animals are confined to small cages and held in close proximity, this environment provides the prime conditions for diseases to transfer between animals and ultimately to humans. The poaching of species like pangolins and trading exotic pets is yet another source that spreads these pathogens to human populations.
People often point to the overwhelming force of nature as the culprit behind diseases like COVID-19, portraying humans solely as the victims — powerless to prevent or escape the diseases that nature creates. Others look to foreign countries as a scapegoat. Ultimately, however, human interaction with the environment plays an outsized role in the emergence of these zoonotic diseases among humans. In nearly every part of the world, people infringe on natural habitats for resources and space, directly contributing to the emergence and spread of zoonotic diseases.
That’s why to put an end to the spread of zoonotic diseases, human-environment interactions must be restructured: The planet and the species who inhabit it are not resources to be endlessly exploited. Ultimately, living together responsibly and compassionately promotes all forms of health — be it animal, environmental, or human.
By Sarah Street, Communications Intern
Originally posted on October 9, 2020