Tricky Science, Real Risk
Climate Change and Health
By Jessica Keralis
Earlier this summer, The New York Times published an article on the complicated scientific relationship between climate change and health outcomes. The article’s tone was cautious, and it acknowledged early on that public health initiatives based on climate risk are politically fraught, and, in some cases, the science is not as robust as some would like. Several health-effects that environmental advocates frequently link to climate, including vector-borne diseases (e.g., malaria and dengue), natural disasters, and temperature extremes were examined, along with the strength of the research behind each association. The central point of the article is that the science examining climate and its effects on health is, as most scientists will cheerfully admit, quite complicated, and the data that the scientific community has on the subject is incomplete and patchy for many countries and geographic regions.
Korea is certainly no stranger to climate-related health woes. I was warned about “yellow dust” almost as soon as I arrived in Korea in 2012. This spring phenomenon in which prevailing winds bring clouds of fine dust from the deserts of northern China and Mongolia, causes sore throats and respiratory distress in healthy people and can be fatal for those who already have asthma or other respiratory conditions, Pollution and desertification in recent years has made the problem worse. The country’s autumn haze also made headlines, not to mention Jen Lee’s “Dear Korea” comic, this year, with Greenpeace challenging the conventional wisdom that China is the primary culprit. According to the group’s analysis, Korea’s own coal-fired power plants could be responsible for up to 70% of the fine particle-laden smog, also known as PM2.5; at best, it is a 50-50 split. Greenpeace alleges that the air pollution generated by the country’s coal plants are responsible for up to 1,600 deaths.
The link between air pollution and health-effects is pretty clear-cut, but what about climate change itself? Are disease-carrying vectors like mosquitoes really expanding their range, and if so, does that directly result in more cases of mosquito-transmitted diseases? The US National Oceanic and Atmospheric Administration (NOAA) established that 2015 had the hottest summer ever recorded, but are heat waves and temperature extremes definitively linked to more deaths or hospitalizations? Alas, answers to these questions are less clear. “There’s a lot of evidence showing that extreme weather can hurt people, but what we don’t know is whether those effects are getting worse,” says Columbia University Climate and Health Program director Patrick L. Kinney, who points out that scientists do not yet have the long-term data needed to pinpoint how climate change is affecting health. Similarly, Mary H. Hayden, a scientist who studies climate and health, explains that it is difficult to establish with certainty that climate is directly driving vector-borne diseases. “I don’t think we can dismiss the role of climate. But can we say there is a direct causal link? No, we can’t. It’s more complex than that.”
This, of course, is the primary struggle with translating science into real political action: complexity is difficult to convey, and scientific research has an extremely high bar when it comes to making definitive statements. Findings are always open to challenge, research is always ongoing, and climate change in particular can be politically toxic because it is so closely intertwined with energy and economic policy. The upside to this, however, is that we now have much more data than we used to, in no small part, thanks to increased political will and a greater sense of urgency.
Waiting for the science to be indisputable carries its own costs. In the early years of the HIV epidemic, for example, many epidemiologists had a good idea of what was causing AIDS, but because the science of virology was not as developed as it is now, it took nearly seven years for the virus itself to be identified. As a result, they received pushback from politicians, business leaders, and blood banks demanding proof before they were willing to take action. The scientists’ warnings went unheeded, and many more died as a result. Climate change activists are facing a similar struggle now. As Dr. Kinney noted in the New York Times piece, “…if we wait for the health evidence to be ironclad, it may well be too late.”