How Climate Change Affects Your Health Now and in the Coming Years


We've been hearing about rising oceans and destroyed vegetation as a result of increasing global temperatures for decades. And while the warnings have only gotten more dire and urgent, we often overlook that climate change affects the health of not just the earth, but also those who inhabit it.

If you thought climate change wasn't hurting humans in the here and now, consider that some parts of the world (like Australia and Scandinavia, and even stateside in Texas) continue to see record-breaking heat waves, along with heat-related illnesses, which can be deadly. In Australia, for example, the number of heat-related deaths from 2000 to 2009 was 532, nearly as many as the country experienced in the three prior decades combined.

These environmental dangers are directly affecting our ability to live, breathe, and thrive in the present—and will only continue to do so. Read on to find out how climate change is currently affecting our health, and how it will affect our health in the future.

Now: We're having trouble breathing.


Climate change leads to shifts in the quality of the air, both from human-made pollutants and changes in natural allergens, like pollen. And people with breathing problems are especially sensitive to changes in air quality and temperature, which is already becoming a problem.

A 2018 study published in the American Journal of Respiratory and Critical Care Medicine found that air pollution has already resulted in more ER visits for those with these breathing issues across the U.S.

With every 20 parts per billion (ppb) increase in ozone, the rate of ER visits for respiratory problems increased 1.7 percent among children, 5.1 percent among adults under 65, and 3.3 percent among adults over 65.

Now: Disease is spreading more widely.


Increased hot and wet conditions—which climate change has created—mean more mosquitoes, creatures who are notorious for spreading illnesses like West Nile virus and Lyme disease. These are called vector-borne diseases (VBD), and the vectors can include fleas, ticks, lice, and rodents, in addition to mosquitoes.

When a disease is primarily spread by an animal or insect, it's usually limited to a geographic area where that animal or insect can live. But as temperatures rise, so do the populations of certain animals and insects. Mosquitos can now live at higher altitudes that have traditionally been malaria-free because the insects couldn't survive there. A 2014 study published in the journal Science looked at malaria cases in the Antioquia region of western Colombia from 1990 to 2005, and the Debre Zeyit area of central Ethiopia from 1993 to 2005. The researchers saw a correlation between malaria outbreaks and rising temperatures in these formerly malaria-free environments.

Now: Our contaminated water is making us sick.


Hurricanes and rising temperatures go hand-in-hand. According to the journal Health Affairs, "the devastation caused by Hurricane Harvey was in part the result of Gulf surface temperatures for the first time on record never falling below 23°C." Over the past two to three decades, the United States has seen a 45-87 percent increase in the frequency of Category 4 and 5 hurricanes as a result of climate change, according to a 2012 study published in the Journal of Climate.

These storms in turn affect the quality of drinking water, and consequently do damage to our health. Flooding and runoff can contaminate water with bacteria, viruses, and parasites, which lead to diarrheal diseases that cause dehydration. And without clean water to rehydrate, the problem becomes even worse. For example, a significant 2008 study published in the journal Emerging Infection Diseases found that after Hurricane Katrina, the number of reported cases of West Nile sharply increased in the hurricane-affected regions of Louisiana and Mississippi.

Contaminated water can also grow toxic algae blooms that can make people even sicker. And if that wasn't bad enough, the sheer amount of water from a flood can cause sewage systems to overflow and mix with drinking water. 

Now: We're more at risk for skin cancer.


Climate change and the depletion of ozone are two separate—but linked—issues. The rising level of carbon dioxide and CFC gases (chlorofluorocarbons) in the atmosphere has both fueled climate change and resulted in the depletion of the ozone layer, according to a 2012 Harvard study published in the journal Science. Climate change also does damage to the layer of the atmosphere that protects humans from damaging UV rays. And when UV radiation gets through, our risk of skin cancer increases significantly.

A notable 2009 study published in the Journal of the Royal Society of Medicine looked at the connection between climate change and skin cancer. The researchers noted that, "Ozone depletion has lead to an increase in skin cancers and worryingly this is still rising." And an oft-cited 2002 study published in the journal The Lancet found that an increase in skin cancer cases in Chile among people under 50—from 12 percent to 20 percent of the population—was directly related to the depletion of the ozone layer.

Now: Our allergies are worse and longer lasting.


Sure, compared to skin cancer, allergies may seem less worrisome, but more and more people are suffering from allergies every year—and climate change appears to be the culprit.

A pivotal 2005 Harvard study found that rising temperatures and the increase in carbon dioxide in the atmosphere are causing plants to flower earlier in the year (kickstarting allergy season) and encouraging them to produce more total pollen and fungi than they had in the last several decades. A 2014 paper published in the European Respiratory Review explained that environmental conditions such as extreme heat, high humidity, and cyclones—all of which are consequences of climate change—have been associated with a rise in allergies.

In the future: Our air and food will be contaminated with mercury.


The Arctic Ocean is loaded with mercury, lurking under permafrost where it's been trapped since the Ice Age. Usually the element binds only with living matter. But because of the Arctic's low temperatures, plants there have not fully decomposed, meaning their roots have frozen and still contain poisonous mercury. The substance is extremely toxic, causing visual and verbal impairment, weakness, poor coordination, and all kinds of other health issues in humans that come into contact with even small amounts of it.

The bad news is, according to a 2018 study in the journal Geophysical Research Letters, about 32 million gallons of mercury have built up in the Arctic, poised to be released if, or more likely when, the permafrost thaws. That's the equivalent of 50 Olympic swimming pools—"twice as much mercury as the rest of all soils, the atmosphere, and ocean combined," as the study's authors put it—that could be released into the Arctic and from there, into the atmosphere.

And it gets worse: Mercury continues to build as it moves through the food chain (a process called biomagnification). It's hard to say how damaging the release of even a fraction of that 32 million gallons would be, but it will likely first hit the wetland and aquatic ecosystems in the Arctic, then soon contaminate humans' food supply from there. 

In the future: We'll suffer from more heart attacks.


Cardiovascular disease is already the leading cause of death in the United States, and climate change is only going to make it more deadly. Rising temperatures aren't just bad for your lungs—they're bad for your heart, too.

A 2011 study published in the American Journal of Epidemiology found that increased temperature levels can be bad for a person's heart. According to the study, high temperatures in the summer months in the U.S. were associated with a decrease in the regularity of subjects' heartbeats. And a drop in heart-rate variability is linked to an increased risk of death following a heart attack.

And then, of course, there's the issue of air pollution, which increases as a result of climate change, according to the Centers for Disease Control and Prevention (CDC). Pollution has also been associated with an increased risk of heart attacks. In fact, a 2013 meta analysis published in the journal The Lancet found that air pollution increases a person's risk of suffering a heart attack by 4.8 percent. This greater risk is partly because the pollutants encourage inflammation of the lungs, which causes inflammation of the heart.

In the future: We won't be getting enough nutrients.


One of the biggest dangers presented by climate change is the damage it's expected to do to our food supply because of droughts, soil erosion, and greenhouse emissions.

A 2010 study published in the International Journal of Life Cycle Assessment found that more than one-third of the planet's land surface is at risk of desertification, meaning that a serious drought could be the difference between crop-friendly soil and land that's too degraded to grow anything on. For example, National Geographic points out that most of Egypt's crops are cultivated in the Nile Delta, but the erosion and saltwater intrusion that would result from a drought could leave the entire region with little arable land.

Another 2018 study published in the Proceedings of the National Academy of Sciences of the United States of America found that if greenhouse gas emissions continue on their current trajectory, the global production of vegetables and legumes could fall by 35 percent, due to lack of water and increased salinity. In fact, according to the study, just a 4-degree increase in temperature would result in 86 percent probability that the top 4 corn-producing countries on the planet would experience simultaneous production losses of more than 10 percent a year.

That's a huge portion of the globe that could be without a sustainable food source, considering corn is also the main source of nutrition for cows. Malnutrition is a problem in itself, but it also increases a person's susceptibility to disease. And speaking of that, droughts spread mold that produces aflatoxin—which is believed to contribute to the development of liver disease in people who eat contaminated crops, according to a notable 2008 study in the Journal of Integrative Plant Biology.

And if that all wasn't bad enough, one of climate change's many documented effects has been an increase in crop pests, such as aphids and locusts, according to the National Institute of Environmental Health Sciences.

In the future: The summers will be lethally hot.


One of the most obvious results of global warming is that warm months will become unbearably hot. For some, that might seem like the minor inconvenience of dealing with sweat stains and indoor Fourth of July barbecues. But for many, it could mean a life-or-death situation. Research published in the journal EcoHealth in 2018 predicts that the eastern U.S. could see minimum summer temperatures could rise by 3.3°C. By the researchers' predictions, that means that by the middle of the 21st century, 11,500 Americans could die annually as a result of heat exposure.  

This is likely to be even worse in urban areas. According to 2014 research from the Natural Resources Defense Council, the so-called "Urban Heat Island effect" will cause average summer temperatures to increase about 1°C more on average, compared to rural counties. 

In the future: We won't be getting enough sleep.

Climate change is likely to make it harder for people to sleep. That's not just due to worries about extreme weather events or all the other health risks outlined here so far. In a 2017 paper published by the journal Science Advances, researchers predicted that if temperatures continue to rise at the rates they have been, by 2050, we can expect an extra six nights of sleeplessness every month—and fourteen (which is nearly half the month) by 2099.

That's because the internal temperature drop that occurs when you lay down at night is a precondition of sleep. In fact, insomniacs often find that a lower ambient temperature helps them fall asleep and stay asleep. As global temperatures rise, we can expect sleeplessness—and the many repercussions of it, including fatigue, anxiety, forgetfulness, and decreased immune system response—to only increase.