In the wake of major outbreaks involving diseases such as Dengue, Ebola, and COVID-19, researchers have pointed to the planet’s role in the rise of pandemics. With the threats of climate change more apparent than ever, the relationship has been made abundantly clear.
Deforestation and urbanization are bridging the physical divide between humans and animals. Increased close contact also expedites the likelihood of outbreaks of zoonotic diseases, such as HIV, SARS, and Avian Flu, among human populations. Research from Guangzhou, China, points to alarming rates of fever due to Dengue, a mosquito-borne viral disease, as a result of sudden changes in temperature caused by climate change. Experts warn that continuing to disregard natural buffers such as forests and wetlands for urban sprawl will promote exposure to deadly pathogens.
A report from the National Emerging Special Pathogens Training and Education Center (NETEC) shows that the sudden increase in intense weather events has caused vector-borne diseases to double over the last 20 years. In the same report, the NETEC cautioned that while certain species of ticks may disappear as a result of climate change, their adaptability may pan out in the formation of new tick-borne diseases. In fact, since 2000, six new pathogens derived from ticks have been discovered, a result of both emerging medical technology and species evolution.
At the same time, these human-centered activities also damper, if not permanently alter, ecosystems around the world. The intensification of domestication and production of livestock illustrates the dangers of human intervention. These disruptions can account for booming populations of animals that contribute to zoonotic diseases, like the vampire bat. Farmers and ranchers would purchase and reserve land to serve as grazing areas for their cows, eliminating other species in the area. Paired with a growing population of livestock, the vampire bat was able to thrive with a potential surplus of food. Growing rates of rabies across parts of Central and South America were in large part due to the eradication of predators to the vampire bat and the mass introduction of livestock for prey. Domestic pigs are also a popular culprit of zoonotic diseases, harboring diseases such as influenza and encephalitis. The often crowded conditions that these livestock are raised in, as well as potential breeding, can continue to produce dangerous trends prime for an outbreak.
While deforestation as a practice has slowed down, according to data from Oxford University, the growth rate of trees and greenery has yet to match previous rates of forest loss. Moreover, researchers urge health services and government officials to target root causes for disease—including hunger, poverty, and misinformation—rather than going about eradicating a certain species responsible for a zoonotic outbreak. Other factors such as mass globalization, travel, and a growing shortage of healthcare workers may act as other reasons why outbreaks may be more common. However, climate change continues to be an overarching issue.
By Lois Angelo