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Among the scientific and policy highlights of 2018 were landmark reports on climate change and human health. These brought more insight and urgency to the reality that climate change is happening now and harming our lives in a host of ways. How the U.S. and the rest of the world respond in 2019 will chart the course for our future.

Both reports — one written by 13 federal agencies and released by the Trump administration, the other written by an international group of health experts and published in the prestigious journal the Lancet — specifically point to the fact that climate change is harming human health.


Here’s one of the summary conclusions from the U.S. report: “Impacts from climate change on extreme weather and climate-related events, air quality, and the transmission of disease through insects and pests, food, and water increasingly threaten the health and well-being of the American people, particularly populations that are already vulnerable.”

The effects of climate change are being felt around the world — rising sea levels are inundating parts of Micronesia and Vietnam, a “mega-drought” has plagued central Chile since 2010, and typhoons and other major storms have been growing in intensity and becoming deadlier.

It should come as no surprise, then, that climate change is also affecting the United States. Communities in coastal states are still working to recover from another dangerous hurricane season. No sooner had Hurricane Florence swept through Florida, Georgia, North Carolina and Virginia, killing 51 people, than Hurricane Michael hit the same area, leaving 36 people dead and destroying countless homes.


As two former U.S. surgeons general, one nominated by a Republican president and the other by a Democratic president, we see climate change as a growing threat to the health of all Americans.

Hurricanes appear to be getting worse, and we now know that climate change is driving this. In a report published in Nature, researchers with the Lawrence Berkeley National Laboratory showed that climate change caused rainfall during Hurricanes Katrina, Irma, and Maria, three of the worst storms in history, to be 4 to 9 percent worse than would have been expected without climate change. They also showed that Hurricane Harvey in 2017 dumped 20 percent more rain on the Houston area than would have been expected without climate change. Another study showed that global warming made 2018’s Hurricane Florence 50 percent worse, feeding the storm through warmer sea water and an altered atmosphere.

As the National Climate Assessment states, climate change is causing bigger, stronger, slower-moving, and more catastrophic storms.

In addition to immediate deaths and immense property damage, hurricanes that make landfall harm health in various ways in the months and years that follow. There’s the exposure to toxic substances, and mounting evidence indicates an increase in mental health issues. Many people exposed to extreme weather disasters experience severe stress and serious mental health harms, including depression, anxiety, post-traumatic stress disorder, substance abuse, and surges in suicidal thoughts and behavior.

After Hurricane Katrina devastated the Gulf Coast in 2005, the National Institutes of Health conducted screening for depression in New Orleans and Baton Rouge. The researchers found that depression had doubled in New Orleans and significantly increased in Baton Rouge, with a disproportionate impact on the mental health of those with the lowest incomes. Another post-Katrina study showed that children who lived through the storm were 4.5 times more likely to have serious emotional disturbances than those who were not affected by it.

When the surgeon general’s report on mental health was released in 1999, it stated that “mental health is fundamental to overall health and the public health of our nation.” That is no less true today.

Of course, health harms related to global warming are not limited to hurricanes. Global warming causes increases in heat waves, humidity, and air pollution; extends the length of wildfire seasons and makes fires more intense; and increases rainfall, leading to flooding and mudslides. Extreme heat can cause heat-related illness and death from heat stroke and dehydration. Poor air quality increases asthma and allergy attacks and can cause other respiratory problems leading to hospitalization and deaths. A rise in temperature can also extend the geographic range of disease-carrying mosquitos and ticks, resulting in faster and wider spread of diseases such as Zika.

As residents of Georgia and Arizona, we regularly see health threats from global warming firsthand: extreme heat in the East and increasing wildfires in the West.

Global warming can also poison the food we eat and the water we drink. Rising temperatures and extreme weather conditions make it easier for food and water to become contaminated by bacteria, viruses, parasites, and other toxins. For example, heavy downpours and flooding can spread bacteria from animal and human feces into waterways and fields where crops are growing. NASA released a stunning satellite image showing this kind of runoff in the wake of Hurricane Florence.

Calls to address climate change continue to grow. The recent report from the Intergovernmental Panel on Climate Change warning that we must act within the next 12 years to reduce greenhouse gas emissions by 45 percent has increased the urgency to transition from fossil fuels that contribute to global warming.

We aren’t alone in sounding the alarms of the medical community. Global warming has activated physicians to speak out about how it is affecting their patients. The Medical Society Consortium on Climate and Health, an organization of 22 major medical societies representing more than half the nation’s doctors, along with many other medical groups, are working to alert Americans to the harm from climate change.

While anyone can be harmed by dirty air, extreme weather, and contaminated food and water, those most vulnerable are infants, young children, pregnant women, the elderly, the poor, people of color, and those with chronic illnesses. In New Orleans’ Lower Ninth Ward, which was 98 percent black prior before Hurricane Katrina, 30 percent of people could not evacuate because they didn’t own a car, and were most likely to die in the storm.

Some politicians are standing in the way of — or actively undoing — national efforts to reduce the emissions that cause global warming. Failing to act will hasten the spread of harmful health effects, putting all Americans at increased risk. Now is the time to act by urging elected officials to develop robust plans to lessen the impact of global warming and start improving health conditions in the United States.

If the string of milestone reports isn’t enough, deadly hurricanes and wildfires serve as brutal warnings. No matter where Americans live, climate change — through hurricanes, wildfires, heat, flooding, and the spread of disease — is harming our health, just as it is harming the health of people around the globe.

We’re all at risk and our leaders must lead on global warming. Now.

Richard Carmona, M.D., was the 17th surgeon general of the United States. He is a volunteer member of the Medical Society Consortium on Climate and Health. David Satcher, M.D., was the 16th surgeon general of the United States.

  • ” brought more insight and urgency to the reality that climate change is happening now”

    Yes the climate changes, what a shock. Please let me know when it stops changing, since that would actually be worrisome.

  • Thank you for the article, need to also acknowledge the wild fires in California and other western states. The prolonged drought has made trees weaker and more susceptible to disease and first. Not only have lives, homes and communities been lost, first responders have been exposed to harmful chemicals both during the fire and during recovery including PFAS from air drops, and dangerous fumes and participate matter from combustion. Populations living even 100 miles away experienced weeks of smoke and particulate matter compounding asthma and COPD. Thanks

  • Climates change – no matter what we do. To think that humans cause floods, wildfires, hurricanes etc is preposterously cocky: we are pitifully powerless ants in the big scheme of immeasurably super-powered events like solar flares and the de-stabilizing protective magnetic shield around our planet. These are events we have zero control over, and they happen like it or not. All we can do (if we are smart) is adapt, and address damage reduction: curb construction in hot zones/flood zones, give rivers birth (don’t put the mighty Mississippi in a straight-jacket at its Delta), have more fresh water (shore-side desalination plants), step up organized evacuation assistance, and fund R&D for the new bugs that logically will evolve on a warmer Planet Earth.
    Of course we should not be a pig-headed over-polluting nation (like so many others), but we should accept the inevitability of changes in climate, and be creative in finding solutions. A new Ice Age would be much worse …….

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