Scientists fear another pandemic as humans continuously encroach on wildlife habitats

As climate change worsens and humans push further into wildlife habitats, the risk of animal-borne diseases triggering global pandemics grows more likely. Journalist and filmmaker Harriet Constable joins CBSN's Lana Zak to discuss.

Video Transcript

LANA ZAK: The CDC's relaxation on mask wearing and social gatherings signal progress in the fight against the pandemic, but even with vaccination numbers going up and cases coming down here in the US, there are concerns about the next global health emergency, a particular concern climate change and encroachment on wildlife habitats. Let's bring in journalist and filmmaker Harriet Constable. She is co-producer of the multimedia series, "Stopping the Next One, Scientists Race to Prevent Human Encroachment on Wildlife From Causing The Next Pandemic."

Harriet, thanks for being here. 75% of newly emerging diseases originate in animals. COVID-19 has links to pangolins and bats. How does transmission between animals and humans typically occur?

HARRIET CONSTABLE: Hi, Lana. Well, is a human-created problem time and again. We see that human activities create opportunities for viruses to jump and spill. For example, one of the diseases that we looked at is Nipah virus.

It's a disease we find in Asia that comes from bats. And it's deforestation of bat habitat that gives this disease the opportunity to jump and spill over. This is just one of many opportunities and many examples of human activity giving a virus a chance to reach us. So it's a human-created problem, but also there are a lot of solutions out there that we can be implementing.

LANA ZAK: Well, global warming is altering ecosystems around the globe. China alone has seen 40 new bat species, according to the journal, "Science of the Total Environment." Those bad species are estimated to carry more than 100 types of coronavirus variants. How do we protect ourselves given that the change in global warming in the environment is so much bigger than any one scientist or one individual?

HARRIET CONSTABLE: There are lots of things we can be doing thankfully to better prepare and better protect ourselves when it comes to stopping the next pandemic. Some fantastic work is going on among scientists and great collaborations to learn, where are these diseases spilling over? Why are they happening? And what can we do to prevent them?

So, for example, you talk about climate change. There are scientists that are surveilling the way in which new mosquitoes are finding their way to North America, because it's a more habitable environment for them now that it's warmer. This type of surveillance is really fundamental, because the better we understand and know these diseases, the better we are prepared to try and deal with them when they do spill over from animals to humans.

LANA ZAK: And, Harriet, what other human activities factor into the spread of disease?

HARRIET CONSTABLE: Well, climate change is a huge one that's driving up opportunities, deforestation. And deforestation is happening in Asia and in South America, largely to do with our food systems to create space for livestock and things like palm oil plantations. In South America, deforestation is driving up the chance for yellow fever to jump between humans and monkeys.

And another human activity that is creating opportunities for disease to spread, we found in Europe, is the intensive farming of pigs. This creates a lot of chance for disease to spread and proliferate among herds. So we need to be looking at these opportunities that we're giving these viruses and how we can prevent them in the future.

LANA ZAK: And, Harriet, what are some other viruses out there that are of concern to scientists?

HARRIET CONSTABLE: So in Asia, we looked at a disease called Nipah virus. That can jump from bats to humans. It's on the World Health Organization's list of top 10 diseases that could cause the next pandemic. And it's extremely deadly. It's not a disease that we want to give too many opportunities to.

In Africa, we looked at how herders are moving from having cows to camels because of climate change. And camels have a disease or harbor a disease called MERS, which is a coronavirus like COVID-19, but it's 10 times more deadly. In pigs in Europe, we see swine influenzas. And we had a influenza from swine from pigs in 2009.

So it sounds very, very frightening, but the crucial thing is there's a lot we can do to put ourselves in a better position. The scientists in Europe spoke to us about how we are creating a playground for viruses with industrial factory-farmed pigs. However, we also can be doing a lot to prevent this type of thing.

We could make a mandatory surveillance program for pigs in Europe. We could be looking at changing some of these systems. And that's a really crucial part of the story.

LANA ZAK: I'm so glad that you said that, because I imagine for many of us hearing this with the anxiety that we already have because of the current pandemic that we're in, it's frightening. So it's nice to know that the scientific community is, at least, optimistic about things that we can be doing. And I want to follow-up with you on that point, because given all that we've been through, do you believe that we will be better prepared for the next pandemic? And what are the most important lessons that you're worried that we don't seem to actually be internalizing, even after having gone through all of this?

HARRIET CONSTABLE: Well, certainly we've seen how hugely damaging a global pandemic can be now. And I don't think anyone would want us to be in this position again. So the question of how we better prepare for that, whether it's providing more funding and opportunities for surveillance and research.

One of the scientists that I spoke to in Cambodia is doing fantastic work to understand where Nipah virus is spilling over and spreading in among their communities, but he doesn't have funding for his next pathogen detection trip. This is a really obvious and simple way in which we could be better prepared and better understand what the opportunities are. And I think it's that type of solutions-orientated approach that we need to be taking to put ourselves in a better position for the next one, because scientists told me it's not a case of we can prevent the next pandemic. It's a case of being better prepared and improving our chances.

LANA ZAK: Improving our chances. Let's hope that we have learned those lessons. All right. Harriet Constable, thank you so much for joining me.

HARRIET CONSTABLE: Thanks for having me.