Increase in infectious diseases strongly associated with loss of biodiversity
When the COVID-19 pandemic struck the world in 2020, it drew attention to the ways environmental damage can set the stage for disease outbreaks. Scientists pointed to the potential roles of urbanization, habitat loss, and trade in live animals for helping to fuel a disease that many scientists think leapt from wild animals to people.
While all those factors might have influenced this particular pandemic, they aren’t the main ways that environmental destruction threatens to amplify infectious disease. It turns out loss of biodiversity, global warming and the spread of non-native species are the biggest factors, according to a sweeping new analysis of research from around the world.
“We did not know which global change drivers most increased or decreased infections,” said Jason Rohr, an infectious disease ecologist at Notre Dame University who lead the new study. “Disease control efforts were partially flying blind.”
Studies of individual outbreaks have delved into links to a fast-changing world, such as connections between deforestation, hunting and the deadly spread of Ebola in parts of Africa. Scientists have also drawn connections between problems such as climate change and a whole host of diseases.
But this is the first time that scientists have tried to compare and rank the disease-altering effects of major forces changing the environment today: dwindling biodiversity, climate change, chemical pollution, habitat loss and the spread of invasive species.
To tackle such a massive subject, the researchers relied on the work of hundreds of other scientists. Rohr and his collaborators amassed 972 studies that assessed the effects of at least one of these environmental factors and their links to diseases affecting both humans and other organisms. They then analyzed whether an effect was found in each of them, and how strong the effect was.
Biodiversity loss, invasive species and climate change emerged as the three environmental problems with the strongest link to increased disease. Loss of biodiversity stood out. It was associated with a 65% greater increase in disease than invasive species and a 111% greater increase than climate change, the scientists reported last week in Nature. [Continue reading…]