Among the top items Google is promoting today under the search term “climate change” is a paper out of the University of California at San Francisco (UCSF) titled, “Climate Change Will Give Rise to More Cancers.” As the title implies, the study claims climate change will contribute to “higher rates of cancer, especially lung, skin and gastrointestinal cancers,” because climate change will cause poor air quality and disruptions in the food supply. However, there is no evidence climate change has had or will have any impact on cancer rates or treatment. In fact, scientific evidence shows that, by UCSF’s logic, climate change will reduce the number of people getting cancer. Playing on the public’s justified fear of cancer to hype action against climate change alarm is shameful.
In particular, the study asserts climate change will cause an increase in cancer rates and a decline in cancer treatment for three main reasons:
- Climate change will cause an increase in wildfires, putting particulate matter and soot into the air, which, when breathed in will contribute to an increase in lung cancers.
- Climate change will disrupt food supplies resulting in malnutrition, which will contribute to increasing numbers of gastrointestinal cancers.
- Climate change will cause more “[e]xtreme weather events such as storms and flooding [that] can destroy or damage health-care infrastructure, reducing health care quality and availability … [as well as] interrupting service delivery by causing power shortages, disrupting supply chains, transportation, and communication, and resulting in staff shortages.”
Tackling each of these claims in turn, the evidence shows wildfires have declined over the past century even as the earth has experienced a modest warming. As documented in Climate at a Glance: Wildfires, long-term data from the U.S. National Interagency Fire Center (NIFC) show wildfires have dramatically declined in number and severity in recent decades. Reporting data on U.S. wildfires from as far back as 1926, NIFC documents that the number of acres annually burned recently is only1/4th to 1/5th of the annual acres burned in the 1930s.
Globally, the data on wildfires are just as clear. In his book False Alarm, Bjorn Lomborg observes:
“There is plenty of evidence for a reduction in the level of devastation caused by fire, with satellites showing a 25 percent reduction globally in burned area just over the past 18 years … In total, the global amount of area burned has declined by more than 540,000 square miles, from 1.9 million square miles in the early part of last century to 1.4 million square miles today.”
Because there is no evidence climate change is causing an increase in wildfires or the air pollution they emit, there is equally no evidence climate change is causing more incidences of lung cancer.
Real-world data concerning crop production directly contradict the UCSF study’s claim that food supply disruptions will lead to more gastrointestinal cancers. The evidence is clear food production is improving with modest warming and higher carbon dioxide concentrations.
Data from the United Nations Food and Agriculture Organization (FAO) show yields of the most important cereal crops have increased dramatically over the past few decades, repeatedly setting new records. As shown in the chart below, the FAO’s recent “Cereal Supply and Demand Brief” reports new global records are being set nearly every year for production of the cereal crops (corn, wheat, rice, and similar crop staples) that comprise most of global food consumption.
FAO Cereal Supply and Demand Brief, August 10, 2020.
Cereal grains include the Big Three food staples of corn, rice, wheat and similar crops. Corn, rice, and wheat by themselves comprise 66 percent of global human food consumption. Cereal crops alone make up nine of the 15 crops that provide 90 percent of the humanity’s food energy intake. As shown above, the FAO reports cereal grain production set new records seven of the past 10 years.
Global warming lengthens growing seasons, reduces frost events, and makes more land suitable for crop production. Also, carbon dioxide is an aerial fertilizer for plant life. Fruits and vegetables also benefit from longer growing seasons, fewer frost events, and from the fertilization effect of increased levels of carbon dioxide. As a result, climate change-induced crop abundance has resulted in the largest decline in hunger, malnutrition, and starvation in human history.
Increasing amounts of nutritious food means cancers related to diet and nutrition should decline as well.
Finally, data recorded by the U.S. government and the International Panel on Climate Change (IPCC) presented in Climate at a Glance: Drought, Climate at a Glance: Floods, and Climate at a Glance Hurricanes, show that the number and severity of droughts, floods, and hurricanes have not increased during the past few decades of modest warming.
Concerning floods, the IPCC has said it has “low confidence” in any climate change impact regarding the frequency or severity of floods.
Concerning drought, the 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, and it has “low confidence” about any negative trends globally. Data also show, the United States is undergoing its longest period in recorded history with fewer than 40 percent of the country experiencing “very dry” conditions, and in 2017 and 2019 America registered its smallest percentage of land area experiencing drought in recorded history.
Data from the IPCC and the National Oceanic and Atmospheric Administration (NOAA) show no increase in the number or severity of hurricanes in recent decades. Indeed, NOAA reports, the United States recently went through its longest period in recorded history without a major hurricane strike. American also recently experienced its fewest total hurricanes in any eight-year period.
Since the evidence is clear that climate change is not causing more extreme weather events, it must also be true climate change isn’t making it more difficult to treat people for cancer by disrupting medical supplies or disrupting travel to hospitals and clinics for cancer treatment.
The UCSF study is filled with alarming claims and speculation but short on facts. The available evidence indicates people have no reason to fear climate change is making or will make cancer more common or more difficult to treat. People who fear cancer should instead fear that climate hucksters will try and use fear of climate change and false cancer links to divert money and resources away from direct cancer treatment and research, steering it instead toward climate research.