The Link Between Cancer and Climate Change

According to a new study by public health experts, climate change increases the production of—and exposure to—known carcinogens. Global warming also threatens people’s access to effective cancer treatment following exposure.

The study was produced by researchers from the American Cancer Society and Harvard University and published in CA: A Cancer Journal for Clinicians. Cancer is currently the second-leading cause of death globally. According to the researchers, almost 10 million people worldwide will die from cancer in 2020.

Many cancers are now frequently preventable and potentially curable, thanks in part to increasingly effective cancer therapies. Early detection, and the identification and control of cancer risk factors, also support cancer prevention and cure.

“The prospects for further progress in cancer prevention and control in this century are bright, but face an easily overlooked threat from climate change,” explains the study’s authors, Leticia M. Nogueira Ph.D., MPH, K. Robin Yabroff Ph.D., and Aaron Bernstein MD, MPH.

“Climate change is already increasing cancer risk through increased exposure to carcinogens,” they continue. “After extreme weather events such as hurricanes and wildfires. In addition to increasing cancer risk, climate change is also impacting cancer survival.”

Extreme weather events expose people to carcinogens and simultaneously reduce their ability to seek support. These events can also severely impact the medical infrastructure that is essential for effective cancer care.

Mitigating the continuing impact of climate change will positively affect both planetary and human health. The reduction of air pollutants, in general, could help prevent additional global warming. It could also reduce people’s exposure to airborne carcinogens.

Cancer Care and Climate Change

According to the researchers, there is no data that estimates the overall impact of cancer care on the environment. Many indispensable facets of effective cancer care—including medical devices, radiotherapy, packaging, and transporting various resources—contribute significantly to greenhouse gas emissions.

However, many of the contributors to cancer care’s environmental footprint present opportunities to reduce emissions. For example, operating room ventilation can be optimized and energy efficiency improved. Reducing vehicle emissions and sourcing low-carbon food options could also dramatically cut cancer care’s contribution to climate change.

In a press release, the authors suggest that climate change and continuing reliance on fossil fuels push the “noble goal” of cancer eradication further from reach.

“While some may view these issues as beyond the scope of responsibility of the nation’s cancer treatment facilities, one need look no further than their mission statements, all of which speak to eradicating cancer,” they write.

“If all those whose life work is to care for those with cancer made clear to the communities they serve that actions to combat climate change and lessen our use of fossil fuels could prevent cancers and improve cancer outcomes, we might see actions that address climate change flourish, and the attainment of our missions to reduce suffering from cancer grow nearer,” continue the authors.

Animal agriculture is a significant contributor to climate change, while some experts link eating meat with an increased risk of cancer and other chronic diseases. Reducing meat consumption could help reduce cancer risk—both by improving health and mitigating climate change.

Meat and Health

Diet is a key factor in both cancer risk and climate change. In 2018, a major report from the World Cancer Research Fund and the American Institute for Cancer Research suggested that plant-based foods could help reduce cancer risk.

Researchers found evidence that red and processed meat increase the risk of colorectal cancer. They also revealed that dairy consumption may increase the risk of prostate cancer.

Cancer Research UK says: “Eating lots of processed and red meat can increase the risk of bowel cancer. If you’re eating lots, it’s a good idea to try and cut down.”

In 2015, The World Health Organization (WHO) classified processed meat as a Group 1 carcinogen. This places processed meat alongside known carcinogens tobacco and asbestos. The WHO also classified red meat as Group 2A, meaning that it “probably” causes cancer.

The WHO’s website indicates this is “based on sufficient evidence from epidemiological studies that eating processed meat causes colorectal cancer.”

“The strongest, but still limited, evidence for an association with eating red meat is for colorectal cancer. There is also evidence of links with pancreatic cancer and prostate cancer,” explained the WHO.

According to The Mayo Clinic, a nonprofit academic medical center, approximately a third of cancer cases could be prevented by swapping animal products for a plant-based diet. The high fiber and phytochemicals content of plants that may protect cells from damage.

“There is a lot more evidence to move towards a plant based diet,” says Mayo Clinic Healthy Living Program dietitian Angie Murad, RDN, LD. Other research finds that just 10 grams of daily fiber could lower the risk of colorectal cancer by 10 percent.

Meat and the Environment

In addition to increasing the risk of cancer, animal products have a significant impact on the environment. According to the creators of the 2014 documentary film “Cowspiracy,” animal agriculture causes 18 percent of global anthropogenic greenhouse gas emissions.

In 2018, the United Nations Environment Programme named meat “the world’s most urgent problem.”

Nuffield Council on Bioethics released a briefing note in 2019 highlighting the environmental impact of high-intensity farming. Nuffield Council directly compares animal agriculture to the sustainability and health of vegan alternatives and clean meat.

Animal agriculture is inefficient, and raising animals for protein uses up a disproportionate quantity of land, water, and other resources. In 2016, the top 10 most-cited reasons for buying vegan meat did not include the environment.

According to the Food and Agriculture Organization of the United Nations, nearly 50 percent of the world’s grain is fed to livestock, yet there are about 800 million people globally suffering from hunger and malnutrition.

In 2018, Oxford University researchers found that adopting a vegan diet is the “single biggest thing” an individual person can do to minimize their impact on the planet. By 2019, the environment became the third most popular motivator for those cutting down their meat consumption.

Animal welfare and health concerns—including the increased risk of cancers and other chronic health conditions—are also some of the most common factors in going meat-free.