It’s safe to say that some aspects of climate change have been engrained in the minds of many by basic science and the media. Even those who are minimally informed—or don’t believe in climate change to begin with—have most likely heard the same murmurs: ozone levels are rising, storms are becoming irregularly common and intense, and polar bears have been rendered homeless as glaciers melt at unprecedented rates.

Indeed, there is a certain set of attention-grabbing information that typically accompanies climate change talk. We see headlines about the latest tropical storm in Florida streaming across the bottom of the televised weather update, we watch doomful movies about erased ecosystems, and over the radio we hear again and again that “Today is another record high, folks!” While it’s important—and essential to environmental awareness—that this general knowledge exists, many less tangible realities of climate change don’t come up in the news and probably aren’t taught in most Introduction to Environmental Studies courses.

One such reality is the impact that climate change has on mental health and the brain. Through case studies and empirical studies, scholars and scientists from all over the academic spectrum have pinpointed countless ways that climate change may be profoundly related to both negative mental health outcomes and neurological damage.

From the beginning of climate change conversations in the late 19^th century, scientists examined the potential effects of global warming and greenhouse gases on physical human health; conversely, it wasn’t until around 2010 that the health conversation expanded to encompass full body wellbeing (BBC, 2013). By this time, data undoubtedly determined that global temperatures were rising thanks, in large part, to human pollution that caused the atmosphere to trap the sun’s hot rays (EPA, 2016).

Now, climate change has been deemed one of the greatest threats to human health in the 21^st century, and you better believe that brains and behavior are suffering big time (Bourque, 2014).

Climate change can affect people both directly and indirectly (Berry, Bowen & Kjellstrom, 2010). Indirect impact, for instance, may occur when physical problems, like respiratory distress, caused by climate change lead to psychological problems, like depression. Also indirect is the connection between changes to social environment and mental health: drought may change an agricultural landscape, which in turn could heighten economic pressure on farmers and result in severe stress.

On the other hand, there are the in-your-face-once-you-know-to-look-for-them direct links. For example, someone may directly feel the impact of climate change on her mental health if she experiences severe anxiety in response to an unexpected, catastrophic natural disaster. Likewise, if a family has to be displaced from their home because of land degradation, the mental impact may be hopeless depression. Third, a slew of behavioral reactions—distress, confusion, helplessness—may arise when one simply acknowledges that climate change truly is a “global environmental threat” (Berry, Bowen & Kjellstrom, 2010).

Evidence of such direct connections abounds in the literature. After Hurricane Sandy barreled into New Jersey on October 29, 2012, there were 113 deaths, 200,000 damaged homes, and $50 billion worth of destruction, as well as $2 billion in damages in Cuba and $5 million of economic loss on Jamaica (Neria & Shultz, 2012). As the researchers in this study pointed out, most who experienced this disaster had minimal mental health problems afterwards, instead employing positive coping mechanisms, resilience, and effective adaptation. However, others who were not so fortunate continued their lives post-hurricane with heavy burdens like Post Traumatic Stress Disorder (PTSD), an overwhelming flow of thoughts and emotions related to a traumatic event that develops when people are “unable to process information and feelings in a normal way” (Cohen, 2016). When the unexpected comes—like a super powered storm fueled by overheated arctic jet-streams—there is understandably much to process but little precedence by which to do so.

To follow up on the idea of displacement, researchers have sought out populations whose homes are slowly disappearing. One study, which took place in the shrinking Solomon Islands, asked citizens of this small low-lying country between Papua New Guinea and Fiji what they thought about climate change’s toll on mental health (Asugeni et al., 2015). The vast majority (89%) of the 57 people who were interviewed affirmed that they had “seen the patterns of the weather change,” and 95% of these participants followed up by agreeing that “sea-level rise experience” can lead to mental health effects. Others have followed up on these sorts of feelings by uncovering that the mental health effects most often felt after displacement are rooted in Solastalgia, which is the “loss of solace” that accompanies degradation of something loved (Padhy et al., 2015; Letter to the Editor, 2016).

Acknowledging the rather grim trajectory of climate change also often comes with Solastalgia-esque powerlessness and lack of control. In extreme cases, the anxiety and mood irregularities spurred by climate change awareness can manifest themselves in disorders like Obsessive Compulsive Disorder (OCD), in which people perform behaviors to quell anxiety-driven obsessive compulsions that they have. In one study that looked at the impact of climate change on people who were already identified as having obsessive compulsive checking concerns, 14 out of 50 participants “identified as having OCD concerns directly related to climate change” (Jones et al., 2012).

To give a picture of what these sorts of concerns look like, participants reported obsessively checking light switches for fear that they were wasting electricity and further harming the environment. Others were convinced that sitting water in their homes—like the water in dog bowls—would evaporate because of rising air temperatures (Jones et al., 2012). All in all, climate change’s looming threat amplified the guilt complexes of these already anxiety-ridden participants.

While people with disorders that are promoted, in part, by climate change, are likely aware of the hold that climate change has on them, others who are neurologically affected by aspects environmental change may not be as cognizant. In a vast review of studies that have examined the connection between environmental risk factors and neurological change, the major consistent findings are of “brain-volume alterations” in response to pollution exposure (Calderón-Garcidueñas et al., 2016).

Thus far, these volume alterations have taken the form of either inflammation of brain regions or lesions (small pockets of tissue degradation/damage) in the brain. In one animal model study, mice were exposed to concentrated airborne particle matter for four hours five days a week over the span of two weeks (Campbell et al., 2005). What researchers found was an increase in pro-inflammatory cell secretions in the brain tissue of mice that were exposed to particle matter, compared to controls that did not experience such exposure. Basically, when the mice were exposed to pollutant particles, their nervous systems tried to kick into defense, but this resulted in swelling of immune-related brain cells. Researchers worry that the human response to these same sort of pollutants—the ones that float up into the atmosphere from cars, cigarettes, aerosols, etc., and cause our earth to warm—is also brain tissue inflammation, which over time can lead to the brain physically and functionally breaking down, or “degenerating” (Campbell et al., 2005).

Another striking study compared children and dogs who lived in ultra-polluted Mexico City to counterparts who lived in a less polluted small city, Polotitlán. After undergoing magnetic resonance imaging (MRI) scans, researchers concluded that 56% of the 55 kids living in Mexico City had lesions in their prefrontal cortices, which is part of the brain dedicated to executive functioning tasks like planning, decision making, and managing social encounters (Calderón-Garcidueñas et al., 2008). Only one child from the less polluted town had a similar lesion. Meanwhile, four of the seven dogs (57%) also showed frontal lesions.

So, clearly pollution is not our friend just as much as it’s not Mother Nature’s friend. Though it may have taken us a while to arrive at the conclusion that the brains and behavior of humans are affected by climate change on many levels (factors that contribute to climate change, events that result from climate change, and even the idea of climate change itself), we are now better positioned to address environmental degradation and human health moving forward. That the studies I have pulled from range so widely in discipline (public health, neurology, psychology, environmental studies) and country of origin (Australia, India, Mexico, the US) indicates to me that academia and the public are finally giving this topic the attention that it deserves and so desperately needs. If fruitful studies of all sorts of populations from all corners of the world continue, continue to explore the psychologically- and neurologically-grounded affects of climate change, we can only hope that humans’ drastic harm to our environment—and, subsequently, harm to ourselves—subsides.

 

References

A brief history of climate change. (2013). BBC. Retrieved from http://www.bbc.com/news/science-environment-15874560

Asugeni, J., MacLaren, D., Massey, P. D., & Speare, R. (2015). Mental health issues from rising sea level in a remote coastal region of the solomon islands: Current and future. Australasian Psychiatry: Bulletin of Royal Australian and New Zealand College of Psychiatrists, 23(6), 22-25.

Berry, H. L., Bowen, K., & Kjellstrom, T. (2010). Climate change and mental health: A causal pathways framework. International Journal of Public Health, 55(2), 123-132.

Calderón-Garcidueñas, L., Leray, E., Heydarpour, P., Torres-Jardón, R., & Reis, J. (2016). Air pollution, a rising environmental risk factor for cognition, neuroinflammation and neurodegeneration: The clinical impact on children and beyond. Revue Neurologique, 172(1), 69-80.

Calderón-Garcidueñas, L., Mora-Tiscareño, A., Ontiveros, E., Gómez-Garza, G., Barragán-Mejía, G., Broadway, J., . . . Engle, R. W. (2008). Air pollution, cognitive deficits and brain abnormalities: A pilot study with children and dogs. Brain and Cognition, 68(2), 117-127.

Campbell, A., Oldham, M., Becaria, A., Bondy, S. C., Meacher, D., Sioutas, C., . . . Kleinman, M. (2005). Particulate matter in polluted air may increase biomarkers of inflammation in mouse brain. Neurotoxicology, 26(1), 133-140.

Climate Concepts. (2016). Environmental Protection Agency. Retrieved from https://www3.epa.gov/climatechange/kids/basics/concepts.html

Cohen, H. (2016). What Causes PTSD?. Psych Central. Retrieved from https://psychcentral.com/lib/what-causes-ptsd/

Jones, M. K., Wootton, B. M., Vaccaro, L. D., & Menzies, R. G. (2012). The impact of climate change on obsessive compulsive checking concerns. Australian and New Zealand Journal of Psychiatry, 46(3), 265-270.

Letter to the Editor. “Climate change and mental health: Rationale for research and intervention planning.” (2016). Asian Journal of Psychiatry, 20, 1-2.

Neria, Y., & Shultz, J. M. (2012). Mental Health Effects of Hurricane Sandy: Characteristics, Potential Aftermath, and Response. JAMA: The Journal of the American Medical Association, 308(24), 2571–2572.

Padhy, S. K., Sarkar, S., Panigrahi, M., & Paul, S. (2015). Mental health effects of climate change. Indian Journal of Occupational and Environmental Medicine, 19(1), 3–7.