No, Climate Change Does Not Cause Cancer

Among the top articles in a May 19 Google News search for “climate change” were a slew of articles claiming climate change causes cancer. CNBC and several other major news outlets published the claims, citing American Cancer Society (ACS) activists making the assertion. The line of reasoning is preposterous. And even if the ACS’s line of reasoning were sound, the line of reasoning would indicate that climate change is reducing cancer incidence and mortality.

The CNBC article is titled “Climate change is fueling extreme weather that lowers cancer survival rate and threatens prevention.” The article points out ACS’s line of reasoning as “[1] Climate change has triggered more frequent weather disasters like hurricanes and wildfires that [2] release deadly carcinogens into communities and [3] delay access to cancer treatment.” Each of the three prongs of the argument is ridiculous, and the three in combination give new meaning to the term “far-fetched.”

Examining the first prong, climate change has clearly not “triggered more frequent weather disasters like hurricanes and wildfires.” As documented in Climate at a Glance: Hurricanes, hurricane impacts in the United States are at an all-time low. The United States recently went more than a decade (2005 through 2017) without a major hurricane measuring Category 3 or higher, which is the longest such period in recorded history. The United States also recently experienced the fewest number of hurricane strikes in any eight-year period (2009 through 2017) in recorded history. Even the U.N. Intergovernmental Panel on Climate Change 2018 “Interim Report” observes there is “only low confidence for the attribution of any detectable changes in tropical cyclone activity to anthropogenic influences.” And, as shown in the chart below (see climatlas.com/tropical/frequency_12months.png), there has been a declining number of hurricanes during the past 30 years, not an increase as ACS claims.

Also, drought is the climate component that would impact wildfires. As documented in Climate at a Glance: Drought, the United States is benefiting from fewer and less extreme drought events as the climate modestly warms. In 2017 and 2019 successively, the United States registered its smallest percentage of land area experiencing drought in recorded history. Also, the United States is undergoing its longest period in recorded history with fewer than 40 percent of the country experiencing “very dry” conditions. Moreover, the U.N. IPCC reports with “high confidence” that precipitation has increased over mid-latitude land areas of the Northern Hemisphere (including the United States) during the past 70 years, while IPCC has “low confidence” about any negative trends globally. (See https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf, p. 191.)

The entirety of ACS’s claim that climate change causes cancer rests on the notion that climate change causes more hurricanes and wildfires. With those assertions convincingly debunked, ACS’s entire argument fails. If anything, ACS shows that climate change causes less cancer.

Let’s nevertheless look at the remaining two prongs of ACS’s claim.

The second prong, that a modest increase in wildfires would release more cancer-causing carcinogens into the air, would be marginal, at worst. Very few, if any, cancer cases and cancer deaths are linked to a person being exposed to forest fire smoke. And, again, even if that were the case, we see that climate change is reducing the drought that causes forest fires.

The third prong, that hurricanes and forest fires delay people’s access to cancer treatment, would also be marginal, at worst. Very few, if any, regularly scheduled cancer treatments are missed because someone is caught in a hurricane or wildfire. And, again, even if that were the case, we see that climate change is reducing the frequency of hurricanes and wildfires that would force somebody to miss a cancer treatment.

In summary, activists at the American Cancer Society, together with their willing media puppets, have gotten the entire issue backwards, if there is any link at all. Climate change is not causing more cancer, but it apparently is causing more ridiculous claims from activist groups.