Cholera and Climate Change: The New York Times Gets the Story Exactly Backwards

If you wonder why the public is so ill-informed about global warming, the following head-exploding story is illuminating. The New York Times appears to be downplaying the role of climate change. You be the judge.

A few weeks ago, some experts on public health and the hydrological cycle came out with a nuanced study in the American Journal of Tropical Medicine and Hygiene examining some recent theories as to why cholera outbreaks occur.

The American Society of Tropical Medicine and Hygiene put out a news release headlined:

Scientists pinpoint river flow associated with cholera outbreaks, not just global warming

Previously, some scientists had seen a correlation between sea surface temperature and cholera outbreaks in certain locations, like the coastal waters of the Bay of Bengal. That puzzled the authors of this new study, “Warming Oceans, Phytoplankton, and River Discharge: Implications for Cholera Outbreaks” (PDF here) for two reasons:

  1. High SSTs are normally associated with a decrease in phytoplankton — the authors cite 8 studies on this. (See also, Nature Stunner: “Global warming blamed for 40% decline in the ocean’s phytoplankton”).
  2. High-levels of phytoplankton are thought to lead to cholera outbreaks. The causal agent of cholera hangs around with copepods, small crustaceans that feed on phytoplankton. So it’s been theorized that “high levels of phytoplankton may lead to high numbers of cholera-containing copepods, increasing the likelihood of cholera epidemics in coastal human populations.”

What the new study found was that in the Bay of Bengal and other large river basins -‑ the Orinoco (in South America), the Congo, and the Amazon — “The positive relationship between phytoplankton blooms and ocean temperature is related to large river discharges,” said Shafiqul Islam, PhD, the lead investigator of the study and a professor in the Department of Civil and Environmental Engineering at Tufts. The rivers discharge “terrestrial nutrients.”

The release notes:

But Islam said that global warming may play a role in other ways in outbreaks of cholera, including contributing to droughts and high salinity intrusion in the dry season and floods in the wet season. Both of those conditions have been found also to contribute to cholera epidemics, as published recently in the journal Water Resources Research. “If river flows are more turbulent, if droughts are more severe, if flood is more severe, cholera is more severe,” he said. “But cholera may not have direct linkage with rising sea surface temperatures.”

Okay, so the main result of the study is that cholera outbreaks may not be causally linked with rising SSTs — though the authors can’t make a definitive statement on that (if you actually talk to them). But cholera outbreaks have been appear to be linked to extreme flooding as well as extreme drought, both of which, of course, have been projected — and even observed — to increase because of climate change!

So what is the headline of the New York Times story?


The news release doesn’t say this at all — quite the reverse. The study doesn’t say this — if you read it. Nor do the authors — quite the reverse. I had an extended interview with Islam yesterday, and, to be clear, he explains that this study simply can’t say whether or not there is a linkage between warmer SSTs and cholera. But his work does suggest that the kind of extreme weather linked to climate change is a culprit in outbreaks. Note — “a culprit,” not the only one.


The New York Times appears to have read the news release, but decided to run with its own perverse narrative. I say that based on the final paragraph of the Times story, which is lifted from the American Society of Tropical Medicine and Hygiene release:

  • NYT: “Cholera seems to be gaining a foothold in more places than it used to,” said Dr. Peter J. Hotez, president of the American Society of Tropical Medicine and Hygiene. “We obviously need to be taking a different approach.”
  • Release: “Cholera seems to be gaining a foothold in more places than it used to be,” Hotez said. “We used to see shorter outbreaks, but in Africa, and now in Haiti, we’re seeing nationwide epidemics lasting months or more than a year. We obviously need to be taking a different approach.”

But the release makes clear that the study is not saying that global warming isn’t a culprit, and the quote in the release from Islam makes clear that in fact it probably is a contributing factor. What is the New York Times doing here, rewriting a headline, ignoring a crucial quote, and generally not doing any actual journalism?

If the New York Times had bothered to talk to Islam, he would have explained the link to climate change in more detail, since he has written multiple studies on the subject, including “Hydroclimatic influences on seasonal and spatial cholera transmission cycles: Implications for public health intervention in the Bengal Delta” and “Dual peak cholera transmission in Bengal Delta: A hydroclimatological explanation.” Islam’s work has shown that both extreme flooding and extreme drought can trigger cholera outbreaks.

In fact, in the Bengal Delta’s dual cholera peak, his research finds that “the spring peak is linked to the severity of drought and the fall peak is linked to the severity of flooding.”

He explained that climate change projections for South Asia mean that “extremes will become more extreme, there will be more flood or drought, and that means cholera will net increase.”

What’s even more perverse is that the NY Times piece contains these paragraphs:

Cholera outbreaks seem to be on the increase, but a new study has found they cannot be explained by global warming.

A bigger factor may be the cycle of droughts and floods along big rivers, according to Tufts University scientists who published a study in The American Journal of Tropical Medicine and Hygiene this month….

Warmer ocean surface waters suppress plankton growth, so scientists had assumed cholera outbreaks would decrease with global warming.But satellite photographs of the mouths of the Ganges, Amazon, Congo and Orinoco Rivers suggest that heavy rainfall and glacier melt have the bigger effect by washing soil nutrients down rivers to feed the plankton blooms.

Is the NY Times really unaware that global warming is not only linked directly to heavy rainfall but obviously to glacier melt?


It is embarrassingly bad stories like these that give credence to the claim by John Horgan, a former Scientific American staff writer who directs the Center for Science Writings at Stevens Institute of Technology:

Two sources at the Science Times section of the New York Times have told me that a majority of the section’s editorial staff doubts that human-induced global warming represents a serious threat to humanity.

The one thing we can say with very high confidence about human-induced global warming is that if we take no serious action to reduce greenhouse gas emissions in the foreseeable future — a do-nothing strategy advanced by fossil-fuel interests and supported by a complacent media — then global warming represents the most serious threat to humanity we have ever known.