As people begin to build and expand into more wild areas, it’s more likely that they’ll come in contact with viruses that circulate in animals. In fact, the U.S. Centers for Disease Control and Prevention (CDC) estimates that three-quarters of “new or emerging” diseases that infect humans originate in nonhuman animals.

As we’ve learned from the damage of the coronavirus, when we fail to take precautions to safeguard wild species, the effects for humans can be catastrophic.

The Links: As Fast & Company reported, the connection between proximity to wildlife and viruses is evident. The current outbreak seems to have started at a Chinese market that sold wild animals for food, including wolf pups, civets, bamboo rats, and crocodiles; pangolins, a type of anteater, may have been the vector.

• The animals, now endangered, have been illegal to sell there for more than a decade, but the laws haven’t been widely enforced.
• China has taken new action to stem illegal wildlife trade, and shut down wildlife markets, though it remains to be seen how permanent the changes will be (after the SARS outbreak, which was also linked to wildlife markets, the markets closed only temporarily.)

F&C also explained that urbanization and globalization also mean that when a virus jumps from an animal to a human, it can now spread quickly. Wuhan, where the new coronavirus emerged, is one example of the overall trend. The city sprawled between 2000 and 2018, tripling in size, while new rail lines and flights connected it to the rest of China and the world.

The History: Some animal-to-human transmitted diseases, like rabies and plague, crossed from animals centuries ago. As Ensia explained, others, like Marburg, which is thought to be transmitted by bats, are still rare. A few, like COVID-19, which emerged last year in Wuhan, China, and MERS, which is linked to camels in the Middle East, are new to humans and spreading globally.

In fact, Peter Daszak, a disease ecologist and the president of EcoHealth told the New York Times that, “Any emerging disease in the last 30 or 40 years has come about as a result of encroachment into wildlands and changes in demography.”

The Science: The New York Times recently wrote that teams of veterinarians and conservation biologists are in the midst of a global effort with medical doctors and epidemiologists to understand the “ecology of disease.”

• It is part of a project called Predict, which is financed by the United States Agency for International Development. Experts are trying to figure out, based on how people alter the landscape — with a new farm or road, for example — where the next diseases are likely to spill over into humans and how to spot them when they do emerge, before they can spread.

Why This Matters: Keeping wild places wild isn’t just an altruistic pursuit–it’s important for animal and human wellbeing (read more about why). Animals have evolved over millennia to be immune to certain diseases and when we encroach on their habitat we expose ourselves to sometimes deadly pathogens. It’s why the pursuit to protect 30% of nature by 2030 is a critical step for public health.