Climate change is not causing West Africa's Ebola outbreak. It sounds obvious, when you say it like that. And yet Emily Atkin of ThinkProgress, a news site usually dedicated to showing how climate change is impacting things, nonetheless found it necessary to call out some overzealous reporting on the matter. Two stories that ran last week, under the guise of asking whether climate change might have something to do with summer's most talked about disease, end up suggesting that it's a primary cause.
"According to three veteran epidemiologists who study how climate impacts disease spread, there is currently no scientific evidence that suggests a climate link to the current Ebola outbreak," Atkin wrote last Friday. "Prematurely reporting on this link is harmful, they say, because it undermines good research that is being done on the growing link between global warming and other types of infectious diseases, such as malaria and cholera."
My first thought, weirdly enough, was, “Oh, that was brave of her." Perhaps it's because climate deniers, in their quest to debunk everything ever said about man-made global warming (starting, of course, with the fact that it's happening and that it's caused by human activity), are constantly accusing the media of doing this very thing: pushing a climate connection where it doesn't exist. In fact, several denier-oriented sites I occasionally monitor (but prefer not to link to) had anticipated this one. (They don't deserve bragging rights for doing so, however, because they're also quick to discount the good, plentiful and peer-reviewed research linking climate change to a host of other diseases and extreme weather events.)
Atkin calls out two pieces in particular: one in Newsweek, and another from CNBC. Both appear to have grabbed a pitch from the same nonprofit, EcoHealth Alliance, about how West Africa's Ebola outbreak can be tied to climate change. The first is mostly a bait-and-switch. It name-drops the two big buzzwords, "Ebola and climate change," and then asks, "Are Humans Responsible for the Severity of the Current Outbreak?" But the article itself mostly focuses on that second question. It discusses the way the changing climate has been linked to other infectious diseases, like malaria, but admits it's difficult to draw a definitive connection in this case. CNBC is more aggressive, asking whether climate change is "key" to the outbreak and asserting, in its very first sentence, that climate change could make future Ebola outbreaks more frequent. It argues that changing weather patterns, by affecting the behavior of fruit bats, could be responsible for the severity of this outbreak. But as Jason Rohr, who studies disease ecology at the University of South Florida, explains to Atkin, local weather events are not the same thing as long-term climate trends, and the article "irresponsibly" conflates the two.
There's good reason to believe that human activity, in general, is contributing to the current Ebola outbreak. The Newsweek article discusses how the expansion of agriculture and deforestation, along with travel and trade, could be playing a role -- similar sentiments have been expressed in other media outlets, including Salon. When that happens, climate change usually merits a mention. As Annemarie Dooling wrote in her introduction to a community discussion, “The spread of Ebola has been linked to deforestation, the consumption of bush meat and population shifts to urban areas, all of which are consequences or causes of climate change.” As arguably the most harmful result of humanity's impact on the planet, climate change is tied up with everything else. And once you're trained to look for it, it's hard not to see it everywhere.
But it's a lot trickier to point fingers directly. Forbes Tompkins, a meteorologist and research analyst with the World Resources Institute, explains that even when we know that climate change is linked to an extreme weather event, or the spread of an infectious disease, we can only say that it made it more likely -- not that it actually caused it. And the chain of events can be tenuous. Tompkins points, as an example, to the 2011 Texas drought. According to several peer-reviewed studies, a heat wave that occurred during the drought was made 20 times more likely to occur by climate change; that heat wave then amplified the severity of the drought. Instead of a clear case of cause and effect, it was more of what he described as a "spider web-oriented ripple effect." And even that is more than sometimes turns out to be happening: One major report from the National Oceanic and Atmospheric Administration, looking back on 12 extreme weather events that occurred in 2012, found evidence that climate change played a role in about half of them.
On the flip side, it's perfectly plausible that human activity can contribute to a major event without climate change ever entering the equation. For this, Tompkins gives the example of the Dust Bowl of the 1930s, which occurred before the era of man-made warming. Drought, in this case, was amplified by irresponsible land use. Human activity and climate change, while intricately related, are not always one and the same.
As the current scientific understanding of climate change is that it is going to make extreme weather events worse -- and, by extension, contribute to the spread of some infectious diseases -- it's not unreasonable for the media to want to bring it up. For one thing, it's a way to make a complicated, even boring topic so much more exciting. Which would you rather read about: climate models (yawn), or SUPERSTORMS and BRAIN-EATING AMOEBAS!? It's also, I'd argue, a really important and effective tool for raising the public's consciousness of the ways that climate change is already affecting us now and, barring significant action, will bring a whole other world of hurt in the future. But there are ways to do this while still being accurate: We can't, again, say that climate change caused any one event. We can suggest that climate change could be playing a role in a certain event (“climate change still influences Ebola, it influences everything,” one expert told Atkin), or explain that it will make such events more likely in the future, but our current level of scientific understanding doesn't allow us to attribute anything to climate change until after the fact, once scientists have had time to conduct comprehensive research.
So yes, it's very easy to get ahead of ourselves, as was the case with Ebola. While it's valid to speculate about the way climate change could be contributing in this outbreak, Tompkins explains, it's way too soon to know where it falls on the list of other contributing factors. It's also easy to understand why the experts interviewed by Atkin sounded so annoyed. In the popular imagination, climate change has taken on a life of its own, as a narrative that can, at its most extreme, explain either everything or nothing about our current world. But for scientists, it's about just that: science. And just as some people's fierce personal desire for it not to be happening can undermine our understanding of that science, so too can the impulse to cry climate prematurely. “Because the whole climate change debate has been so controversial, we’ve got to be doing solid science in that area,” Andrew P. Dobson, an ecology and evolutionary biology professor at Princeton University, told Atkin. “If people start saying inflammatory things, it just messes up the whole funding arena for everybody else.”