These days it is hard to avoid thinking about the COVID-19 outbreak. I am mostly working on climate issues, and I am sure there are conspiracy theories about how they are linked. Conspiracies aside, there is one way that the virus and our climate are definitely linked, and that is through deforestation. Let me explain.
There have been a number of relatively recent disease outbreaks with novel diseases, diseases that western science had not seen before, and often diseases that the communities where the outbreaks originate had not experienced before. Most of these diseases are also originally transmitted to people from tropical wild animal populations, with bats and primates implicated in some of them. What is happening is that the deforestation process works in a variety of ways, driven by factors like new road construction and the development of plantations. As roads reach new areas, it increases both the cutting of trees and the shooting of wildlife for food. Some of the wildlife is eaten locally and replaces food sources lost as deforestation progresses, some of the hunting takes advantage of the new roads and transports the food to urban markets where there is often a high demand for bush meat. With the hunting taking place in places where very few people have hunted previously that are now available for exploitation due to new roads, or places where hunters are no longer living isolated communities, hunters are running into novel diseases in the same way that a survey of biodiversity in places that have not been explored/exploited before find new species of geckos, salamanders, and monkeys. It makes perfect sense that if you are finding new species of animals and plants, you are running into new microorganisms, some of which will eventually be used to cure diseases, others that will cause new diseases, and most that have little direct effect on humans.
The climate link is that the protection and maintenance of good health in the global forest, and especially tropical forests, is a critical part of our strategy to prevent the worst effects of climate change. We have to move toward zero carbon emissions rather quickly, but we also have to suck carbon dioxide out of the sky and trees and soils are the most natural and least energy intensive ways to do that. The best way to keep the trees and soils healthy is to protect tropical forests. We are already seeing reports how the carbon budget of the tropical forests is turning negative. Deforestation is the big driver, but a decent amount of the loss of carbon in tropical forests is a cascade effect. As forest turn silent, as the animals are all hunted out even if it is prior to deforestation, the forest unravels. No animals are eating seeds that need to go through digestive systems to germinate. No animals are depositing seeds in their poop as they move from place to place. Very small pests run amok with predators gone. The ability of the forest to sequester and store carbon falls apart, requiring ever greater efforts to de carbonize to preserve the climate, and new ways of sequestering carbon dioxide already in the atmosphere.
The conclusion is that the process that brings the new diseases to humans, deforestation and the bush meat trade is part and parcel of the climate crisis, and to better prevent future novel diseases, we need to do a lot better job of protecting the forests that help keep the climate intact.