Climate Change Will Increase Likelihood of Pandemics
A new study published in Nature last week suggests that climate change will increase the likelihood of future pandemics caused by animal-to-human transmission. Increased global warming and more frequent and extreme climate disasters are pressuring animals to migrate to new environments where they interact with other species for the first time. New hosts allow pathogens and viruses new opportunities to mutate and jump species -- an occurrence that threatens endangered species and can result in "zoonotic spillover” to humans, as seen in the recent COVID-19 pandemic.
Researchers predict that even if warming is kept under two degrees Celsius by 2070, there will still be 4,500 transmissions between species with a high potential for spillover to humans.
Many species-to-species jumps will be "dead ends” for viruses, but the ones that do manage to mutate and find new hosts could be very dangerous.
Democracy Now: We Created the Pandemicene | Ed Yong on How the Climate Crisis Could Spark the Next Pandemic, April 29, 2022.
DW: Understanding the links between animals, humans and our environment | COVID-19 Special, April 16, 2022.
Why This Matters
When escaping sweltering temperatures and climate change impacts, animal species often migrate to places where humans are building cities or planting crops. The potential for unprecedented interactions between species will increase the likelihood of pathogens spreading and eventually transmitting to humans.
"Climate change is creating innumerable hotspots of future zoonotic risk or presents a zoonotic risk right now in our backyard," says Colin Carlson, a global change biologist at Georgetown University and study co-author.
Outbreaks of Ebola, HIV, bird flu, SARS, and most likely COVID-19 were started by virus spillover from wildlife. With a rapidly warming climate, an even deadlier and more contagious pandemic could be on the horizon.
LA Times: How pandemics are linked to climate change, May 21, 2022.
BBC: Past seven years hottest on record, EU satellite data shows, January 10, 2022.
Cornell Lab of Ornithology: Stop Spillover, Prevent Pandemics, September 26, 2021.
The Next One
Researchers predict that high-elevation ecosystems and places with greater biodiversity, such as Africa and Asia, will have the most overlap in the next couple of decades as species migrate upwards to escape increasing temperatures. The study focused heavily on mammal species because they are the most likely candidates to impact humans with spillover. However, zoonotic spillage is also expected from birds, mosquitoes, and other animals that the study did not consider. According to the study’s model, bats will drive most virus transmissions because of their ability to fly quickly over long distances, increasing their interaction rate with other species. Consequences will affect humans and wreak havoc on animal communities and their health.
Conservation International: Biodiversity and Pandemics, September 23, 2021.
Harvard Chan C-CHANGE: How To Prevent Future Pandemics, August 17, 2021.