Climate Change and Zoonotic Diseases – UPSC GS3

Summary: With a worsening trajectory of climate change parameters across the world, an increased incidence of zoonotic diseases is also being witnessed.
What are the key drivers of the increased incidence of zoonotic viruses?
  • Viruses account for almost 50% of new and emerging diseases. Since the mid-20th century, about 75% of all emerging viruses are zoonotic, they spill over into humans from wild animals.
  • The key drivers of this process are deforestation and climate change.
  • Fact: The 20th century had three pandemics (Influenza 1918, 1957, and 1968) but the 21st century has already experienced two (Swine Flu 2009 and Covid-19) with a few narrow misses like SARS, Ebola, and Zika.
Why zoonotic disease incidence is increasing?
  • Though humans comprise only 0.01% of the Earth’s biomass, we have changed this planet so much that we are in Anthropocene or the Age of Man since the mid-20th century.
  • Increasing livestock population, with genetic links to wild animals and proximity to humans, acts as a natural intermediary for the spill overs. South and Southeast Asia with high densities of human and livestock populations are particularly at risk.
  • Deforestation brings wild animals near both livestock and humans, increasing the risk. For example, Malaysia cleared about 5 million hectares of primary forests between 1983 and 2003 for industrial logging, palm oil plantations, etc.
  • Redistribution of species: Climate change is leading to increased global expansion and redistribution of the Aedes mosquito, which is the vector for several known human diseases such as yellow fever, dengue, chikungunya, rift valley fever, Zika, and lymphatic filariasis.
Scroll to Top