Yet another risk from climate change is rearing its head, researchers say, causing infectious diseases to show up in new places and in new hosts.
By altering and moving habitat zones home to pathogen-carrying animals, climate change could make outbreaks of diseases such as Ebola, H1N1 and TB in the future worse and more frequent, zoologists say.
Two scientists studying disease-carrying parasites in drastically different and separated environments -- Daniel Brooks in the tropics and Eric Hoberg in Antarctica -- say the future of diseases and their spread could look much more bleak with ongoing climate change.
"Over the last 30 years, the places we've been working have been heavily impacted by climate change. Even though I was in the tropics and [Hoberg] was in the Arctic, we could see something was happening," says Brooks, from the University of Nebraska-Lincoln.
What is happening is that as habitats for certain species are shifted geographically or disappear, parasites that were using them as hosts will simply jump to other species.
This contradicts conventional wisdom that holds parasites have co-evolved along with their usual hosts and therefore cannot adapt quickly to using another species as new hosts.
"Even though a parasite might have a very specialized relationship with one particular host in one particular place, there are other hosts that may be as susceptible," Brooks says.
And because the new host species won't have evolved any resistance to the species-jumping parasites, it may be even more susceptible to the parasitic disease than the original host species, with the dangerous result of epidemics possibly occurring more regularly, the researchers say.
New and more deadly strains of pathogens, carried by new hosts encountering humans as we advance farther into wild habitat, could increase the rate of epidemics, they warn.
"We have to admit we're not winning the war against emerging diseases," Brooks says. "We're not anticipating them. We're not paying attention to their basic biology, where they might come from and the potential for new pathogens to be introduced.
"It's not that there's going to be one 'Andromeda Strain' that will wipe everybody out on the planet," he says, referencing the 1971 science fiction film about a deadly pathogen. "There are going to be a lot of localized outbreaks putting pressure on medical and veterinary health systems. It will be the death of a thousand cuts."
