Sunday, May 01, 2022

Animal melting pot created by climate change could lead to new disease outbreaks. (SCIENCE Magazine)




Every time a developer kills another forest with deforestation here in North Florida, the chances of another global pandemic increase.

Shady, foreign-funded developers with undisclosed investors (some Russian), are ruining our County and risking our lives.

I am running for the open Seat 2 at the Anastasia Mosquito Control District of St. Johns County,

In Sicily, with the 82nd Airborne Division in 1943,  my father suffered malaria in WWII.

The Army doctor told him he got it in North Africa. The 90-day wonder was wrong, and mosquitos on Sicily did not read his medical textbooks.  

My dad suffered for decades from the after-effects of malaria, a mosquito-borne disease, 

The next global pandemic could be a mosquito-bonre disease. 

Like incumbent Commissioner Jeanne Moeller, current chair Anastasia Mosquito Control District of St. Johns County (AMCD), I believe in public policy decisions based upon good science. 

From SCIENCE Magazine (published by the late David Brian Wallace, my BFF's longtime employer of thirteen years) the American Association for the Advancement of Science, against which we won a worker rights victory before the National Labor Relations Board and District of Columbia Human Rights Commission in 1992, vindicating worker rights there forever): 





Animal melting pot created by climate change could lead to new disease outbreaks

As habitats shift, many mammalian species will meet each other for the first time and swap viruses, modeling study predicts

28 APR 20225:00 

By JON COHEN

Earth’s warming climate is expected to change the habitat of many animal species, which a new modeling study predicts may spell trouble: Species on the move will mingle with many others they have never encountered before, allowing the various animals to exchange viruses. That could spark new disease outbreaks in many wildlife populations—and in humans as well.


By 2070, assuming the most conservative warming scenario, there will be at least 15,000 new cross-species transmissions involving more than 3000 mammalian species, according to a modeling team led by Colin Carlson, a global change biologist at Georgetown University. “Most of this pattern has probably been set in motion with the 1° of warming we’ve already experienced,” says Carlson, whose study appears online in Nature today.


It’s becoming increasingly clear that climate change will have an effect on the spread of infectious diseases, says Skylar Hopkins, a disease ecologist at North Carolina State University who specializes in parasites, and this “solid study” offers new insights. “They’ve given us a quantitative estimate of how big the risk is for viral sharing in wildlife and where it’s going to happen,” Hopkins says. “But we really don’t know what this means for human health.”


The modelers calculate there are some 21 million possible pairings of mammalian species, and only 7% of those duos currently share a geographic range, which means there’s a tremendous opportunity for new encounters. “Most species on Earth haven’t met each other yet,” Carlson says.


Carlson’s team wanted to know how that might change in the decades ahead. Their models explored four scenarios for climate change, called Representative Concentration Pathways, which range from 2°C to 4°C increases and forecast how each would alter mammalian habitats and mingling. Then, they factored in which first encounters might lead to viral exchanges—only 6% of the possible pairs harbor viruses from the same families, suggesting those could swap pathogens at a future encounter.


Carlson says several findings surprised him. “We get a completely different geography of risk than we expected,” he says. He anticipated that climate change would drive species north and south toward the poles, but the models showed intense mixing occurs earlier, because species will move to habitats at higher or lower altitudes. Bats, which make up about 20% of all mammals, will have an outsize impact on mixing because their ability to fly allows even nonmigratory species to travel hundreds of kilometers over a lifetime, far more mobility than most small animals. “Bats have the hand on the steering wheel of how bad this is,” Carlson says. And virus swapping will concentrate in high-elevation, species-rich ecosystems of Africa and Asia, not, as other models have suggested, at higher latitudes. “Models let us talk about the nuances of the future,” he says.


For a concrete example, the team did a case study of Zaire ebolavirus, which they predict has 13 possible mammalian hosts based on known susceptibility factors. Adding in dispersal limitations of species, they estimate that the least dramatic climate change scenario could cause the virus to be involved in more than 2000 first encounters between two species, of which nearly 100 might lead to a jump from one species to the other. Those leaps could cause deaths in some of these species but could also lead to Ebola infections in humans in the Horn of Africa, where the disease has never been seen.


Quantifying the impact of climate change on first encounters and new viral transmissions adds an important parameter to the modeling that’s been done earlier, says Erin Mordecai, a Stanford University ecologist who studies climate change and infectious disease dynamics. But Mordecai stresses that the study’s real strength is in the big picture, not the nitty-gritty details, which are often complicated by such factors as predicted dispersal patterns and distinctions within a genus. (Bats alone have tremendous variation.) “The specific numerical and geographic projections in the model should be taken as very coarse hypothetical estimates,” Mordecai says.


Although Carlson says there is no way to undo the species mixing that climate change has already caused, he believes we can better mitigate the risks to humans. Leaders in pandemic prevention, for example, have put great emphasis on the threats posed by wildlife markets and deforestation, which both increase encounters between humans and mammals. But that only accounts for a small percent of the actual risk, Carlson says. Surveillance efforts should also intensify whenever a species is found far from its original habitats, such as the Brazilian free-tailed bats that have greatly expanded their range in the southeastern United States over the past decade. Such long-haul travelers have lots of fresh opportunities to exchange viruses with other species.


“Plan long term around a world where we can’t put this back in the box,” Carlson says. “Wishful thinking is our enemy.”


Animal melting pot created by climate change could lead to new disease outbreaks

As habitats shift, many mammalian species will meet each other for the first time and swap viruses, modeling study predicts

No comments: