“People are already suffering and dying from climate change [and] the current estimates are certainly significant underestimates of the people being affected,” says Kristie Ebi, a professor in the Center for Health and the Global Environment at the University of Washington. “These are preventable deaths.”

How global warming and climate change hurt your health

Global warming and climate change are often used interchangeably, but they are different. Global warming, the long-term heating of Earth’s surface as a result of human activity, is just one aspect of climate change. The long-term changes in Earth’s temperature, sea levels, wind, and precipitation patterns are known as climate change.

Climate change has been called “the greatest global health threat,” increasing the risk of a number of potentially life-threatening conditions.

1. Heart disease 

Extreme heat has been linked to an increase in heart attacks, strokes, and other cardiovascular events.

Sweating, dehydration, and loss of salt in your system make your blood thicker and cause your heart to work harder. Heat also triggers inflammation, which can have an adverse impact on your heart, according to Kai Chen, Ph.D., assistant professor at Yale School of Public Health and director of research at the Yale Center on Climate Change and Health.

2. Infectious disease

A changing climate means the earlier arrival of spring and later onset of fall, and those shifts have increased risk of infectious diseases by 58%.

Chen notes that a warming climate has allowed mosquitoes, ticks, and other disease-carrying insects to expand their geographic range, adding, “In the winter, it’s not cold enough to kill the insects, so there is more chance to transmit viruses.”

In addition to higher rates of Lyme disease, dengue, and other vector-borne diseases, an increase in hurricanes, floods, and other extreme weather events has increased the global risk of other pathogens, including hantavirus, adenovirus, encephalitis, and COVID-19.

3. Dementia 

Climate change has made wildfires more frequent and severe, and the fine particulate matter that pollutes that fills the air (and your lungs) when wildfires burn could have an impact on your cognitive health.

“When you look at the types of air pollution that increase the risk of dementia, wildfires are number one,” says Dr. Dale Bredesen, professor at University of California, Los Angeles.

The particulate matter from wildfires has been linked to a higher risk of developing dementia, with some estimates showing that it could cause up to 188,000 cases of dementia annually. Research is still needed to determine the exact connection but there are several theories, including the potential for air pollution to increase inflammation and contribute to the development of plaques in the brain.

“Anything that decreases the blood flow, oxygen, and mitochondria and increases inflammation can increase the risk of dementia,” says Bredesen.

4. Chronic kidney disease

For those working outdoors, high heat and humidity could have an irreversible toll on the kidneys. On days with extreme heat, there was an uptick in the number of emergency room visits for urinary tract infections, kidney stones, and acute kidney injury.

“Most people don’t understand that heat is a serious health risk,” says Ebi.

Heat stress is the main risk factor for developing chronic kidney disease of nontraditional origin, which is a fatal condition that is unrelated to diabetes, hypertension or other causes of kidney disease. It’s more common in workers who perform manual labor in hot environments.

The condition, which is believed to be a result of dehydration, physical exertion, drinking sugar-sweetened beverages, and other stressors on the kidneys, has been called an “epidemic” in Central America, and some data shows that it affects 15% of those who frequently work in hot environments, including laborers in the U.S..

5. Respiratory disease

Warmer temperatures mean more allergens; droughts increase wildfire risk; and climate change increases the amount of ground-level ozone. Currently, 99% of the global population breathes air that exceeds the World Health Organization guidelines for pollution limits.

“Particles of a particular size embed themselves deep in the lung, get absorbed by the lung tissue, get into our bodies, and lead to respiratory issues,” Ebi says.

Air pollution has been linked to numerous respiratory illnesses from pneumonia and chronic obstructive pulmonary disease (COPD) to lung cancer; it’s responsible for 6.4 million deaths every year, making air pollution that leading global environmental cause of illness and premature death.

6. Mental health issues

The term “eco anxiety” has become part of the lexicon with 68% of adults admitting to feeling anxious or worried about the impact of climate change, according to an American Psychological Association (APA) survey.

Climate change does have a very real impact on well-being. Studies have found that post-traumatic stress disorder (PTSD) is common after experiencing extreme weather events such as hurricanes and wildfires. Survivors of the 2018 Camp Fire in California had rates of PTSD similar to those of war veterans.

Hospitalization for psychiatric disorders and suicide rates also appear to be higher during heat waves. Chen points to sleep issues as a potential cause for the mental health impacts of climate change.

“When we have very hot days, you probably won’t get a good sleep if you don’t have air conditioning,” he says. “Sleep disturbances can also lead to mental disorders.”

Protect your health

It might not be possible to turn down the thermostat on the planet overnight, but there are things you can do to reduce the health impacts of climate change on your health. 

During heat waves:

• Turn on electric fans
• Soak your feet in cold water
• Apply ice towels 
• Drink lots of cold water 

When the air quality index is poor:

• Avoid outdoor activities
• Keep windows and door closed
• Wear N95 or KN95 masks 

During times when ticks are common in your area:

Wear long sleeves and long pants and apply insect repellent to protect against flea and tick bites that can spread infectious disease.

Combatting climate change is essential

In the APA survey, six out of 10 adults had changed behaviors to reduce their contributions to climate change.

You can reduce greenhouse gas emissions by walking, biking, or driving an electric vehicle, eating less meat and dairy, reducing food waste and shopping local to minimize carbon emissions created during shipping. These individual actions can have a collective impact, notes Chen.

“In the first year of COVID-19, we had lockdowns [and] at home quarantine…and in major cities across the world, we saw reductions in the traffic emissions…and much cleaner air [because] when you reduce the fossil fuel emissions, you will reduce air pollution,” he says. “It shows that when people act together to reduce the fossil fuel emissions, there are immediate benefits to the environment that can translate into direct health benefits.”