Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Impact of climate change on mortality underlined by global study

Key clinical point: Inhalable particulate matter (PM) is associated with daily increases in cardiovascular, respiratory, and all-cause mortality worldwide.

Major finding: Each 10-mcg/m3 increase of 2-day moving average of particulate matter with an aerodynamic diameter of 10 mcg (PM10) was linked to 0.44% greater daily all-cause mortality.

Study details: The findings are based on a time-series analysis of PM10 and PM2.5 averages and 59.6 million deaths from 652 cities across 24 countries during 1986-2015.

Disclosures: The research was funded by grants from research institutes and ministries in China, the United Kingdom, Australia, Spain, the European Union, South Korea, Finland, Estonia, Czech Republic, and the Health Effects Institute. The authors had no conflicts of interest.


Liu C et al. N Engl J Med. 2019;381:705-15.


The negative effects of climate change on global public health are already playing out around us, but scientific research shows that they will only get worse – unless we begin addressing the issue in earnest now.

At the macro level nationally, effective policy is actually being stripped away right now. “[While] scientists tell us we have little time to wait if we hope to avoid the most devastating effects of climate change, leaders in Washington, D.C., are attacking science and rolling back Obama-era rules from the Environmental Protection Agency,” such as working to weaken vehicle fuel-efficiency standards, relaxing methane emissions rules, ending mercury emissions regulation and taking other actions that will only increase air pollution.

“If these EPA rollbacks are successful, they will diminish our ability to mitigate health effects and diseases related to the burning of fossil fuels and the immense toll they take on our families. ... If we stop supporting and listening to the best available science, if we allow more pollution to be emitted, and if we start limiting the EPA’s ability to monitor and enforce pollution standards, then we put at risk everyone’s health – and especially the health and future of our children.”

Engaging in advocacy and communicating to our representatives that we want stronger regulations is one way people can personally take action, but we can take immediate actions in our everyday lives too. Rather than dwelling on the despair of helplessness and hopelessness that grips many people when it comes to climate change, this moment can be reframed as an opportunity for people to make decisions that immediately begin improving their health — and also happen to be good for the planet.

“To me, the most urgent challenge when it comes to health and climate change is the reality that, when climate change comes up, in the U.S. audience, the first thing that should come into people’s minds is that we need to do this now because we need to protect our children’s health. ... Too many people either don’t get that it matters to help at all, or they don’t get that the actions we need to take are exactly what we need to do to address the health problems that have been nearly impossible to deal with.”

For example, problems like rising child obesity and type 2 diabetes rates have plagued public health, yet people can make changes that reduce obesity and diabetes risk that also decrease their carbon footprints, he said. “One of the best ways to deal with obesity is to eat more plants, and it turns out that’s really good for the climate” Additionally, getting people out of cars and walking and cycling can reduce individuals’ risk of diabetes – while simultaneously decreasing air pollution. “We need to be doing these things regardless of climate change, and if parents and children understood that the pathway to a healthier future was through tackling climate change, we would see a transformation.”

The value of local policy actions should be emphasized, such as ones that call for a reduction in a city’s use of concrete – which increases localized heat – and constructing more efficient buildings. Healthcare providers have an opportunity – and responsibility – not only to recognize this reality but to help their patients recognize it too.

“We can also use our roles as trusted advisers to inform and motivate actions that are increasingly necessary to protect the health of the communities we serve.” They also need to be vigilant about conditions that will worsen as the planet heats up: For example, medications such as diuretics carry more risks in higher temperatures, and patients taking them need to know that.

The need to address climate change matters because we face the challenge of protecting the world’s most vulnerable people.

“One of the great things about climate change is if it causes us to rethink about what we need to do to protect the future, it’s going to help our health today. ... If we can use that as the motivator, then maybe we can stop arguing and start thinking about climate as a positive issue, as a more personal issue we can all participate in and be willing to invest in.”

Gina McCarthy, MS, was administrator of the Environmental Protection Agency during 2013-2017, and Aaron Bernstein, MD, MPH, is a pediatrician at Boston Children’s Hospital. Both are from the Center for Climate, Health, and the Global Environment (Harvard C-CHANGE) at the Harvard T.H. Chan School of Public Health in Boston. Their comments came from their perspective (N Engl J Med. 2019 Aug 22. doi: 10.1056/NEJMp1909643) published in NEJM along with this article and editorial and a phone interview. They reported not having any disclosures.