Putting a human face on climate change

Rainer Sauerborn of the Institute of Public Health at Heidelberg University

December 22, 2016 – Focusing on the potential health impacts of climate change—such as malnutrition, an increase in infectious and chronic diseases, and more deaths from heat waves and cold snaps—may be the best way to communicate its dangers, according to speakers at a recent Harvard symposium.

“Health is the human face of climate change,” said Michelle Williams, Dean of Harvard T.H. Chan School of Public Health, in opening remarks at the event, which drew 150 to Harvard Law School’s Wasserstein Hall on December 13, 2016. The symposium, “Capturing the Carbon Dividend: The Health Benefits of Climate Mitigation,” was sponsored by the Harvard Global Health Institute (HGHI), and featured several experts from Harvard Chan School.

Climate change is often seen as “a remote, abstract problem expressed in parts per million, in terms of temperature change of mere degrees, or in sea-level rises predicted decades into the future,” Williams said. She said that public health experts should present another view, spelling out the dire health consequences that could occur both now and in the future if steps aren’t taken to reduce the carbon emissions that are raising the planet’s temperature.

Symposium moderator Ashish Jha, director of HGHI and K.T. Li Professor of Health Policy at Harvard Chan School, agreed. “If you look at all of the gains that we have made in human health over the last half-century, I think all of that is in some ways at risk if we don’t begin to address climate change,” he said.

Sobering predictions

Keynote speaker Rainer Sauerborn of the Institute of Public Health at Heidelberg University described various climate scenarios that could occur over the next century.

Even if the world was somehow able to immediately curb carbon emissions dramatically—a highly unlikely scenario—global temperatures would still increase by at least 2 degrees Celsius. That’s because the carbon dioxide already released from burning fossil fuels will remain in the atmosphere for thousands of years, leading to effects such as reduced yields of important food crops, more severe storms, and more floods and droughts, he said. If nothing is done to reduce carbon emissions—the worst-case scenario—there will be global warming of 4 degrees or more, a change that could make some parts of the world unlivable. In some coastal areas, rising waters would cover the land. In hot regions, manual labor would become difficult or impossible as the body’s ability to thermoregulate would be exceeded on a regular basis. Health impacts would be felt most strongly by poor countries, because they have the least capacity to deal with them.

While there are some system-wide efforts that could help mitigate these effects—such as developing new vaccines or drugs to combat an increase in disease—these sorts of efforts can only go so far, Sauerborn said. It’s just as important to convince individuals to reduce their “carbon footprint.”

“Households in rich countries—all of us—control 60% of national emissions,” said Sauerborn. “We buy air travel, we have a car, we eat red meat. It’s easy to point to the car industry or to other industries, but there are many things you and I can do to reduce our emissions. Changing individual behavior is key.”

Sauerborn also called for increased research on how reducing climate change could impact health. “There are very few studies that really quantify the health co-benefits of climate policy,” he said.

The future is now

Francesca Dominici, professor of biostatistics and senior associate dean for research at Harvard Chan School, said that while much research on climate change has focused on its harmful health effects in future decades, it’s affecting people right now by increasing cardiovascular disease and respiratory illnesses—and experts should try to get that message across. “Reducing air pollution today would save millions of lives immediately,” she said.

Harvard Chan’s Aaron Bernstein, associate director of the Center for Health and the Global Environment, acknowledged that it’s difficult for people to match cause with effect when the effect is portrayed as far in the future—as is often the case with global warming. “Our brains are simply ill-equipped to deal with climate change,” he said.

He also acknowledged that climate change is as much a political problem as it is a scientific problem. He said the fossil fuel industry “does not want us to understand what is going on” with climate change, and noted that several of President-elect Donald Trump’s Cabinet picks have questioned whether climate change is real.

“There are obviously obstacles,” said Bernstein. But he stressed how crucial it is for scientists to try to clearly show the health downside of climate change—and the upside of curbing it. “We can document the reality that when you deal with this potentially catastrophic problem for human health, you will also achieve the greatest public health intervention in the history of humanity,” he said.

Harvard Chan’s Francine Laden, professor of environmental epidemiology, and Marcia Castro, associate professor of demography, also spoke at the event.

— Karen Feldscher

photo: Andrew Iliff/HGHI