A prescription for better public health: fighting climate change

If you flipped past the Weather Channel this summer, you might have thought you accidentally turned on a disaster movie — with footage of New York City’s skyline blanketed in wildfire smoke, picturesque Hawaiian towns engulfed in flames and quaint Vermont villages underwater. 

But these images weren’t special effects — simply the product of the hottest summer on record. 

This recent string of calamities is just the tip of the melting iceberg. At this moment, people across the planet face a higher risk of injury, illness or death due to climate change — not only from extreme weather events causing mass casualties but also from increases in air pollution, heightened threats of disease after major catastrophes and other downstream effects. 

Clearly, climate change is no longer a looming concern — it is here, and it is already wreaking havoc on our health.

To address climate change’s deadly impact on global public health, world leaders must marshal a massive international collaboration. Tomorrow marks a welcome — and long overdue — step in the right direction: on Dec. 3, the United Nations Climate Conference (COP28) will host a “Day of Health” specifically focused on this crisis.

This historic convening must produce more than soundbites. 

First, we need more government action. There are promising models here: The Inflation Reduction Act directed significant funding to support green energy and the European Union recently required trucks to cut emissions by 90 percent by 2040. These two approaches to mitigation — one a carrot, the other a stick — can be important models for future efforts. To be clear, these acts alone are not nearly enough, but they’re a start. The Day of Health must build on them.

COP28 must also demand real commitments from industry, and our health care sector ought to lead the way. Strong action could make a real difference; the health care sector was responsible for 5.2 percent of net global emissions in 2019 — a number that could triple by 2050.

Without action, we risk a cascade of escalating health impacts from climate change, which drives escalating health care use, which then drives further air pollution and greenhouse gas emissions. Such a future would leave our planet warmer and our people sicker. We must move urgently to net zero emissions across the sector and set an example that other industries — including those with even larger contributions to climate change — can follow. 

Critically, these changes can and must be made without impacting the quality of patient care. For example, research shows that anesthesiologists could reduce the amount of anesthetic gas used during surgical procedures without increasing patients’ risks. Significant reductions would have a real impact on emissions; one study found that using these gases for one hour of surgery is equivalent to driving 470 miles.

Obviously, this one change is not a silver bullet that will solve our problems — but if we can make many changes on the same scale, the effects will compound and make a real impact. Health systems (and all industries) should constantly challenge the status quo in a search for opportunities to reduce emissions without causing harm. As we enter this new reality, we cannot simply stick with processes because “we’ve always done it this way.”

The Harvard T.H. Chan School of Public Health— where I serve as chair of the Department of Environmental Health — is pursuing that work through our Center for Climate, Health and the Global Environment (C-CHANGE). The program offers a strong model for building more resilient clinics; we need more such action in every region at risk.

Internationally, world leadership must provide significant support to the Global South. The region’s low- and middle-income nations are disproportionately vulnerable to climate change’s harms despite emitting very little greenhouse gases, and they lack the capital to respond. Wealthy countries have committed to provide $100 billion per year in climate financing– but that figure is both unmet and insufficient. Developed nations are falling tens of billions of dollars short on their promises, and hundreds of billions of dollars short on actual need.

I’m encouraged that health is finally in the spotlight at a UN Climate Conference. But it won’t mean a thing unless COP28’s Day of Health is also a day of action. 

Global leaders owe it to their nations — and all of humanity — to take strong measures to reduce emissions and mitigate climate-driven health risks. Because this much is clear: Climate change’s health hazards don’t end at borders, and neither should our response.

Kari Nadeau is chair of the Department of Environmental Health at the Harvard T.H. Chan School of Public Health.