— 58% of infectious diseases aggravated by climatic hazards at some point, says Camilo Mora
by Emily Hutto
At the beginning of the COVID pandemic, obviously there was a huge interest in whether this disease was being caused or was caused by climate change. So we decided to investigate this, and very early on we realized that we were not going to get enough access to the data that was required to answer that question.
But while we were doing that search, we found many case examples. In fact, over 20 different case examples that allow [us] to justify climate change, regardless of whether climate change caused COVID or not, we had at least 20 different ways that we can explain COVID.
Let me just give you an example. You think about the craziness of COVID, all of the people around the world that died, the people that got sick, the economic loss of COVID. You think about all of that nightmare, and all of that nightmare goes back to a single incident between a person and a wild animal infected with that virus. That event is called a spillover. So that event, it turns out that it might look very insignificant, but it was the thing that pulled the trigger that made COVID such a big problem at that moment.
Climate change has many different ways that could have caused that spillover. Imagine that bat in the middle of the jungle somewhere — this animal is right there with all the pathogens and we are over here living nicely. We have no conflict with them. We go [to the jungle] with climate change.
Basically, we’re talking about droughts now that force those animals to travel farther away in their search for food. You can also think about wildfires, which now are being aggravated by the drought and the heat, and now this bat loses its habitat; what do you think that animal is going to do? It’s going to start traveling farther away, coming into contact [with people], and then increasing the chances that we generate that first spillover.
We generated a question, and the question is: how many diseases can be affected by climate change?
So what we did is we took every single disease that is registered, almost since the end of the Roman empire, until now. Lucky for us, somebody had collected that data already, so there is a very nice list of diseases. What we did was to take every single one of the diseases and see in the scientific literature if it has been affected by any one of 10 different climatic changes.
When we did that systematically, looking just for case examples in places around the world, we found over 3,000 case examples. Those 3,000 case examples can be clustered in the four different ways in which climate change has impacted humanity.
So the first one was — here is the pathogen, and this is you. The first way is climate change forcing many of these pathogens to move. As a result, they come into contact with us. And in that case, you had hundreds of examples – we just explained the case example with the bat.
The other mechanism that we’ve encountered was climate change forcing us to move. You can think about a wildfire where everybody has to run away, you can think about a flood, a hurricane — everybody has to move. And in that movement we are now the ones that encroach into the habitat of the pathogens, then creating that spillover.