Scientists warn that climate change could trigger the next big pandemic

As the global climate continues to warm, scientists predict that wild animals will be forced to relocate their habitats, likely to regions with large human populations. This will dramatically increase the risk of a viral jump to humans that could lead to the next big pandemic.

The researchers anticipate that as the Earth’s temperature continues to warm, wild animals will be forced to migrate from their habitats, most likely to areas with dense human populations, dramatically increasing the danger of a viral jump to humans. which could lead to the next pandemic.

This connection between climate change and viral transmission is described by an international research team led by Georgetown University scientists in a paper titled “Climate Change Increases Risk of Cross-Species Viral Transmission” published on April 28. of 2022 in the magazine Nature.

In their study, the researchers made the first comprehensive assessment of how climate change will restructure the global mammalian virome. The work focuses on geographic range changes: the journeys species will take as they follow their habitats into new areas. When they meet other mammals for the first time, the study projects that they will share thousands of viruses.

Climate change will drive new viral exchanges between mammalian species

By 2070, human population centers in equatorial Africa, southern China, India, and Southeast Asia will overlap with projected hotspots of interspecies viral transmission in wildlife. Credit: Colin Carlson/Georgetown University

They argue that these changes provide a greater opportunity for viruses like Ebola or coronaviruses to emerge in new places, making them harder to track, and in new types of animals, making it easier for viruses to jump across a species. of “trampoline” in humans

“The closest analogy is actually the risks that we see in the wildlife trade,” says the study’s lead author, Colin Carlson, PhD, a research assistant professor at the Center for Global Health Science and Security at the Georgetown University Medical Center. “We are concerned about markets because putting unhealthy animals together in unnatural combinations creates opportunities for this gradual process of emergence, like the way SARS jumped from bats to civets, and then from civets to people. But markets are no longer special; in a changing climate, that kind of process will be the reality in nature almost everywhere.”

Of concern, animal habitats are disproportionately moving into the same places as human settlements, creating new hotspots of indirect risk. Much of this process may already be underway in today’s 1.2 degree warmer world, and efforts to reduce greenhouse gas emissions may not prevent these events from unfolding.

Another important finding is the impact that rising temperatures will have on bats, which account for the majority of the new shared viruses. Their ability to fly will allow them to travel long distances and share most viruses. Due to its central role in viral emergence, the greatest impacts are projected in Southeast Asia, a global hotspot of bat diversity.

“At every step,” Carlson said, “our simulations have taken us by surprise. We’ve spent years double-checking those results, with different data and different assumptions, but the models always lead us to these conclusions. It’s a really impressive example of how well we can actually predict the future if we try.”

As viruses begin to jump between host species at unprecedented rates, the authors say the impacts on conservation and human health could be staggering.

“This mechanism adds yet another layer to how climate change will threaten human and animal health,” says study co-senior author Gregory Albery, PhD, a postdoctoral fellow in the Department of Biology in the UC College of Arts and Sciences. Georgetown.

“Exactly how these new viruses might affect the species involved is unclear, but it is likely that many of them will translate into new conservation risks and fuel new outbreaks in humans.”

Taken together, the study suggests that climate change will become the biggest upstream risk factor for disease outbreaks, surpassing higher-profile issues such as deforestation, the wildlife trade and industrial agriculture. The authors say the solution is to pair wildlife disease surveillance with real-time studies of environmental change.

“When a Brazilian free-tailed bat makes its way to Appalachia, we need to invest in knowing what viruses are accompanying it,” says Carlson. “Trying to detect these host hops in real time is the only way we can prevent this process from causing more infections and more pandemics.”

“We are closer than ever to predicting and preventing the next pandemic,” says Carlson. “This is a big step towards prediction; now we have to start working on the hardest half of the problem.”

“The[{” attribute=””>COVID-19 pandemic, and the previous spread of SARS, Ebola, and Zika, show how a virus jumping from animals to humans can have massive effects. To predict their jump to humans, we need to know about their spread among other animals,” said Sam Scheiner, a program director with the U.S. National Science Foundation (NSF), which funded the research. “This research shows how animal movements and interactions due to a warming climate might increase the number of viruses jumping between species.”

Reference: “Climate change increases cross-species viral transmission risk” by Colin J. Carlson, Gregory F. Albery, Cory Merow, Christopher H. Trisos, Casey M. Zipfel, Evan A. Eskew, Kevin J. Olival, Noam Ross and Shweta Bansal, 28 April 2022, Nature.
DOI: 10.1038/s41586-022-04788-w

Additional study authors also included collaborators from the University of Connecticut (Cory Merow), Pacific Lutheran University (Evan Eskew), the University of Cape Town (Christopher Trisos), and the EcoHealth Alliance (Noam Ross, Kevin Olival).

The research described is supported in part by a National Science Foundation (NSF) Biology Integration Institutes (BII) grant (BII 2021909), to the Viral Emergence Research Initiative (Verena). Verena, co-founded by Carlson and Albery, curates the largest ecosystem of open data in viral ecology, and builds tools to help predict which viruses could infect humans, which animals host them, and where they could someday emerge. NSF BII grants support diverse and collaborative teams of researchers investigating questions that span multiple disciplines within and beyond biology.

Addition funding was provided by the NSF grant DBI-1639145, the USAID Emerging Pandemic Threats PREDICT program, the Institut de Valorisation des Données, the National Socio-environmental Synthesis Center, and the Georgetown Environment Initiative.

Add Comment