(CNN) We know changes in the weather and seasons can affect mood, causing run-of-the-mill rainy-day blues and seasonal affective disorder. Now, it's also important to recognize the harmful mental and physical health effects of long-term climate change.
In her book "Taking the Heat: How Climate Change Is Affecting Your Mind, Body, and Spirit and What You Can Do About It," author and former CNN meteorologist Bonnie Schneider documents these challenges and shares experts' advice on how to cope.
Here, she offers insights about the impact of climate on health.
This conversation has been edited and condensed for clarity.
CNN: How can climate change lead to health problems?
Bonnie Schneider: Our environment affects the core drivers of health. Temperature changes, air and water quality, food safety and availability, and even our emotional well-being are tied up with our natural surroundings. Changes to these variables can impact both healthy people and those with preexisting conditions.
Take temperature, for example. Ever tried to sleep in a hot room with no air conditioning? Rising temperatures can disrupt sleep and diminish mental clarity and memory, research has shown.
A study of young, healthy college students showed that those who slept with no AC during a heat wave performed worse on cognitive tests the next day than those in rooms with artificial cooling.
Climate change has been linked to certain types of extreme weather events, including intensified floods, wildfires, severe thunderstorms and hurricanes that last longer and produce more rainfall. In 2021, 20 weather and climate disaster events in the US resulted in losses exceeding $1 billion each.
Overall, natural disasters now happen more frequently, impacting more people.
These can cause burns and smoke inhalation from wildfires, injuries from debris falling, and other kinds of harm. Mental health is impacted, too, whether as fallout from trauma, community loss or being displaced. Research shows these psychological consequences can last for years or even decades.
Also important to mention is that natural disasters can affect mental health, even among those who haven't been directly impacted. Upheaval in one's own community can, of course, prompt distress. But just seeing images of weather destruction on TV can trigger anxiety. That's the case even if the specific weather event is not actually linked to climate change.
CNN: What is "eco-anxiety," and how pervasive is it?
Schneider: Eco-anxiety refers to the anxiety and fear that people have over climate change and the future of the planet.
Of people ages 16 to 25, 84% expressed at least moderate worry about climate change in 2021 global survey of 10,000 people. More than 56% believed "humanity is doomed," and more than 45% said their feelings about climate change negatively affected their daily life and functioning.
Experts at the Climate Psychiatry Alliance and the Climate Psychology Alliance confirm the genuine struggles that individuals, especially young people, are having with this kind of anxiety. It can cause severe disruption in daily life, intrude upon people's thoughts and interfere with healthy sleep.
CNN: Do certain medical conditions make people more vulnerable to environmental changes?
Schneider: Yes. Most medical experts say weather extremes of any kind can stress the body. With the climate changing, we're getting hotter days for a longer period of time. This can lead to troubles for people with certain autoimmune diseases that flare up under particular environmental conditions. Lupus, for example, can be triggered by bright sunlight due to UV ray exposure, according to the medical experts I interviewed.
Some evidence suggests relationships between pain and relative humidity, pressure and wind speed. For those suffering from arthritis, more frequent powerful storms may mean more potential for pain. Yet other data negates these findings, such as the study that found no relation between rainfall and outpatient visits for joint or back pain. Still, even these researchers concede the weather-pain correlation may exist, and they urge additional study.
CNN: What does climate change have to do with infectious disease?
Schneider: The loss of biodiversity has become a huge problem. Even small, subtle shifts and disruptions to the natural habitats of wildlife affect humans. We're all part of the ecosystem.
In a September 2020 paper written by Dr. Anthony Fauci and Dr. David Morens, the two infectious disease specialists warn that pandemics are occurring more frequently. They call the Covid-19 pandemic "yet another reminder that human activities represent aggressive, damaging, and unbalanced interactions with wildlife and will increasingly provoke new disease emergencies."
Environmental shifts alter many types of vector-borne diseases -- lyme, for example. When temperatures rise, ticks become more of an issue at northern latitudes, which means we could start to see Lyme disease in places where people don't expect it. This could cause difficulties, given how challenging Lyme can be to diagnose.
Mosquitoes bring additional concerns. More flooding increases their prevalence and the risk of them transmitting diseases.
Then there are the waterborne flesh-eating bacteria.
Rising water temperatures are believed to have brought deadly bacteria to previously unaffected waters. The Vibrio species, for example, can invade the body through any tiny opening in the skin, rapidly causing severe illness and even death.
In June, NOAA scientists in Virginia and Maryland predicted that "as Chesapeake Bay waters warm, Vibrio vulnificus pathogens become more prevalent." (NOAA is the National Oceanic and Atmospheric Administration, an agency of the US Department of Commerce.)
As of August 5, 23 cases of Vibrio vulnificus infection have been reported in Florida alone -- four of them deadly.
Now, we need to add another type of bacteria to our list of concerns.
In 2020 and 2022, two unrelated individuals on the Gulf Coast in Mississippi became sick with melioidosis. This rare and serious infectious disease is caused by direct contact with soil and water contaminated with the bacteria Burkholderia pseudomallei. The CDC (US Centers for Disease Control and Prevention) now cautions people in the region who have health conditions that may put them at higher risk -- such as diabetes, chronic kidney disease, chronic lung disease or excessive alcohol use -- to avoid contact with soil or muddy water, particularly after heavy rains.
CNN: What impact does global warming have on allergies?
Schneider: Allergy season has gotten longer. More frost-free days mean more potentially irritating pollens. There's also a debate among scientists about whether increased carbon dioxide in the atmosphere has made pollen more intense.
Molds are other allergens affected by weather, exacerbated by more frequent storms, intense flooding and damp days.
Many asthma attacks are first triggered by allergies, too. Asthma can be triggered by thunderstorms and wildfire smoke. It's all connected.
CNN: No wonder people are experiencing climate anxiety. What helps them cope?
Schneider: Psychologists and psychiatrists I spoke with emphasized that we can't scoff at eco-anxiety. It's rooted in valid concerns, and people are genuinely troubled.
Experts recommend finding a community of like-minded people by joining groups like the "Climate Cafes" organized by the Climate Psychology Alliance, where you can talk about difficult feelings in a safe space held by trained facilitators. Youth-specific organizations provide other opportunities to connect.
For individual counseling, the Climate Psychiatry Alliance has a directory listing "climate aware" therapists.
Taking actions, large and small, helps, too. Experts advise getting involved with climate justice activism through taking part in events like Climate Week NYC, a global gathering in September with more than 500 events worldwide. Even participating in something local like a beach cleanup can ease worries.
Mindfulness meditation and gratitude are other tools for addressing eco-anxiety. On my website, I give instructions for short, simple mindfulness practices.
When it comes to anxiety, nature has therapeutic effects for both adults and children. Gardening or doing something constructive outdoors -- even during cold weather -- can turn a sense of helplessness into agency. In "Taking the Heat," I outline specific, age-based strategies for children and advice for adults.
Spending time in nature is even healing, interestingly enough, for those who've suffered from trauma at the hands of the elements. Researchers have found that humans have an intrinsic desire to connect with the outdoors after a natural disaster. It's part of the coping process.
For any of us, just 20 or 30 minutes walking or sitting in a place that connects us with nature can lower levels of the stress hormone cortisol.
That decrease is good for mind and body alike.