Understanding the Impact of Climate Change on Mental Health
ANNIKA HESSE
Climate change is without a doubt one of the greatest challenges of our time. As such, scientists have spent much time researching its negative effects on our environment such as rising temperature, floods, droughts, along with a host of many other natural disasters. These extreme climatic events have been observed to have both direct and indirect effects on human pathologies. For instance, heat waves and prolonged exposure to increased temperatures lead to temperature-related illness such as dehydration and heat stroke as well as accelerated death from chronic diseases. Indirectly, rising temperatures can adversely affect the human experience by disrupting critical social infrastructures such as energy, transport, and water and by overwhelming health services.
While many people are aware of the detrimental effects of climate change on the physical health of humans, most do not realize that the mental health of humans is equally impacted by climate change. This can be partially attributed to the fact that specific literature exploring this concept is still lacking and relatively undefined. However, as the fight against climate change continues to rapidly evolve, we must incorporate its impacts on mental health into discussions surrounding climate change in order to holistically address its effect on all facets of the human experience. Additionally, we must investigate how the effects of climate change, specifically those related to mental health, disproportionately affect communities that are already disadvantaged as a result of social, economic, and political expression.
Broadly speaking, there are two different ways climate change impacts mental health. The first is through acute climate fueled disasters, specifically severe weather and disaster events. The second is through the slow-onset impacts of climate change such as higher temperatures and drought. Although they are distinct in the specific effects they have on the psychological well being of people, the implications for mental health of both categories are equally significant.
Climate change has been proven to cause or exacerbate severe weather and disaster events. Although some argue that scientists have not yet been able to fully link climate change to the increase of extreme weather events, there are specific examples to support how the effects of climate change such as increases in temperature intensify natural disasters. As temperatures rise, evaporation intensifies and the transfer of heat from oceans to the air increases. So as storms, specifically hurricanes, travel across warm oceans they pull in more water vapor and heat meaning stronger wind, heavier rainfall, and more flooding when they hit land.
The intensification of these weather events has detrimental effects on the mental health of those affected by them. Post-Traumatic Stress Disorder or PTSD is one of the most widespread forms of post-disaster mental health outcomes. Its symptoms include flashbacks, nightmares and severe anxiety, as well as uncontrollable thoughts about the event. After Hurricane Harvey hit Houston in 2017, at least a quarter of residents reported symptoms meeting the diagnostic criteria for PTSD three months after the event. PTSD is also linked to a host of other mental health problems, including higher levels of suicide, depression, anxiety, and substance abuse. Communities affected by Hurricane Katrina reported a doubling in suicide and suicidal ideation within two years of the hurricane along with 49% of people in the affected area developing an anxiety or mood disorder such as depression. Higher rates of substance abuse were also observed in survivors of Hurricane Katrina. The mental health symptoms that arise as a result of disasters can linger for months or even longer. Research has shown that 5-7 months after a disaster event are typical, but some studies have found that the impacts on mental health last longer than a year or longer. Clearly, the impacts of climate change fueled severe weather and disaster events have a drastic effect on the mental health of those affected by them.
Although not as dramatic as acute events, the incremental impacts of climate change also have drastic effects on mental health. As briefly mentioned above, climate change is resulting in an accelerated increase of Earth’s surface temperature. Since 1880, Earth's temperature has risen by 0.14° Fahrenheit (0.08° Celsius) per decade, but the rate of warming since 1981 is more than twice that: 0.32° F (0.18° C) per decade. The reason for this exponential temperature increase is that the atmosphere today contains more greenhouse gas molecules as a result of human activities such as burning fossil fuels for electricity, heat, and transportation. These greenhouse gasses let visible light from the sun pass through, but they absorb the infrared wavelengths emitted by Earth. As a result of more infrared energy being absorbed by the atmosphere, more energy radiates back down to the surface, increasing Earth's surface temperature rises.
Heat is known to be a physiological and psychological stressor for humans. There is an overwhelming amount of research evidence that establishes a link between increased temperatures and negative mental health outcomes such as mood and anxiety disorders, schizophrenia, and vascular dementia. However, heat can also have less obvious effects on mental health. Specifically, heat creates a low-level stress burden which can manifest itself in ways other than clinically diagnosable mental health problems. For instance, a survey of United States residents found that people felt greater negative emotions and fatigue when temperatures in their area exceeded 70 degrees Fahrenheit. Additionally, extensive research into the psychological impacts of warmer weather on interpersonal aggression has found a casual relationship between the two.
Drought is another slow on-set effect of climate change as warmer temperatures increase evaporation, which dries out soils and vegetation. Farmers are especially affected by droughts as they become threatened by an increased workload, risk of financial hardship, and uncertainty about the future. The degradation of land caused by droughts not only decreases the availability of food and water, but it also creates a sense of shame and humiliation for farmers. This has manifested itself in an increase of farmers’ suicides linked to prolonged droughts.
While the short and long term effects are representative of the psychological changes found in those directly impacted by climate change, there is an additional scope that covers how climate change can indirectly harm mental health. Many people who have not experienced the direct impacts of climate change still suffer from negative emotions surrounding the subject. Although these negative emotions don’t necessarily constitute mental illness, the stress and sadness caused by watching the slow and seemingly never ending impacts of climate change unfold are still a matter of concern. Using a measure developed to look for clinically significant impacts of climate change concerns such as diminished capacity to work or sleep, researchers found that 5-9% of people in the United States described themselves as “often” or “almost always” experiencing such symptoms. A national poll from the summer of 2019 found that 57% of United States teens say that climate change makes them feel afraid. A similar survey emphasized these findings by noting that incidences of disaster events result in a spike of anxiety, stress, and depression in college students. It can be argued that this increase of anxiety is beneficial for the fight against climate change because as an emotional signal that warns us of threats, anxiety has the potential to encourage action. However, the anxiety caused by climate change can easily become greater in proportion to one’s ability to make a difference, meaning that its effects are purely negative.
While the mental health of all individuals can be negatively impacted by climate change, it is important to note that the disastrous effects of climate change on mental health are more likely to affect communities that have been disadvantaged by past and current social, political, and economic oppression. This is due to the fact that disadvantaged communities are more likely to live in disaster prone areas. The economically disadvantaged are more likely to experience
high levels of stress, depression, and anxiety after a disaster for two reasons. First, they are more likely to be exposed because poverty inherently pushes people to higher-risk areas. Second, they face the additional pressure of lacking the financial resources to make their homes more resistant to extreme weather events or to evacuate if a disaster is approaching.
Communities of color are also more likely to live in risk-prone areas as a result of historical discriminatory housing policies, such as redlining and racially-restrictive covenants. These formerly red-lined neighborhoods have been found to be on average, about 2.6 degrees Celsius warmer than non-red-lined areas as a result of lower tree cover and more concrete. The same areas are also often located near polluting facilities such as toxic waste dumps which pose a greater risk of exposure during acute events such as hurricanes.
Indigenous people face an even greater threat to their mental health as a result of climate change because it can not only affect their physical home but also their ways of life. Their personal and cultural identity is often directly tied to the land they live on through history and lived experience, so the degradation of their land by climate change can have an amplified negative effect on their mental health.
The mental health implications of climate change and related inequities cannot be ignored. In order to effectively address climate change and all of its negative impacts, we must look at its effects at the individual, community and societal levels. This starts with understanding the extent to which it impacts the mental health of the human population as a whole as well as how it disproportionately affects certain communities. Although other effects of climate change seem more pressing, it is important to recognize that psychology, as the science of behavior, is integral to the efforts of humans to take specific actions to slow, and hopefully eventually halt climate change. Thus, including mental health in the narrative surrounding climate change is imperative if we as a society are going to protect our climate and our future.