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What are the psychological impacts of climate change?

Susan Clayton
Professor of Psychology at the College of Wooster, Ohio
Jessica Newberry Le Vay
Climate Change and Health Junior Policy Fellow at Imperial College London
Jyoti Mishra
founder and director of the NEATLabs at UC San Diego
Key takeaways
  • Climate change can have consequences for mental health including negative emotions, stress, anxiety, depression, and post-traumatic stress.
  • Rising temperatures have serious psychological impacts, especially for people already suffering from mental health problems.
  • This phenomenon results in an increase in the suicide rate: for every 1°C increase, there is a 1% increase in suicides.
  • Exposure to a climate disaster, such as a fire, can lead to climate trauma.
  • Beyond depression or stress, these events also affect the functioning of our brain and its ability to concentrate.

Increased fre­quen­cy and inten­si­ty of nat­ur­al dis­as­ters, extreme weath­er events, dam­age to bio­di­ver­si­ty and ecosys­tems… The phys­i­cal effects of cli­mate change are now being felt in every coun­try in the world. In its 2022 report “Impacts, Adap­ta­tion and Vul­ner­a­bil­i­ty”, the IPCC high­light­ed for the first time anoth­er impor­tant aspect of cli­mate change: its adverse effect on the well-being and men­tal health of pop­u­la­tions. The cli­mate emer­gency is also a men­tal health emer­gency. For every per­son phys­i­cal­ly affect­ed by a cli­mate dis­as­ter, 40 are affect­ed psy­cho­log­i­cal­ly, says the report from the Grantham Insti­tute at Impe­r­i­al Col­lege Lon­don, UK. But what are the prac­ti­cal psy­cho­log­i­cal effects of cli­mate change? 

In recent years, there has been a lot of talk about eco-anx­i­ety as a way of refer­ring to the neg­a­tive emo­tions gen­er­at­ed by the cli­mate sit­u­a­tion. Susan Clay­ton, Chair of Psy­chol­o­gy at the Uni­ver­si­ty of Woost­er in the Unit­ed States, is one of the authors of the IPCC report. This spe­cial­ist in the rela­tion­ship between humans and nature points out that “eco-anx­i­ety is not in itself a sign of men­tal ill­ness; it is a nor­mal response to a very wor­ry­ing sit­u­a­tion. How­ev­er, some peo­ple reach a lev­el of anx­i­ety that threat­ens their men­tal health. This can affect their sleep, their abil­i­ty to con­cen­trate and work, or to relax and have fun.” 

Eco-anxiety and “solastagy”

The psy­chol­o­gist stud­ied eco-anx­i­ety to deter­mine whether this phe­nom­e­non had real impli­ca­tions for men­tal health, or whether it was just a word for cli­mate “woes”. With her col­league Bryan T. Karazsia, Susan Clay­ton devel­oped a scale based on men­tal health mea­sures. The aim was to check whether mea­sures of eco-anx­i­ety were cor­re­lat­ed with estab­lished mea­sures of psy­cho­log­i­cal prob­lems. And this was indeed the case: eco-anx­i­ety can there­fore, in some cas­es, have a sig­nif­i­cant psy­cho­log­i­cal impact. 

Anoth­er emo­tion is also cit­ed in the report from the Grantham Insti­tute at Impe­r­i­al Col­lege Lon­don, solasta­gia. “It is a feel­ing of home­sick­ness for a place in which you are actu­al­ly liv­ing. It’s see­ing changes in your ter­ri­to­ry, and hav­ing a sense of grief, of loss as a result,” says Jes­si­ca New­ber­ry Le Vay, a fel­low at the Insti­tute for Glob­al Health Inno­va­tion at Impe­r­i­al Col­lege Lon­don. The pop­u­la­tions most affect­ed are chil­dren, peo­ple work­ing on the land, and indige­nous com­mu­ni­ties, who wit­ness first-hand the changes in the land­scape around them. 

The report states that there is a 1% increase in sui­cide rates for every 1°C increase in temperature.

Cli­mate change involves slow and grad­ual changes in our envi­ron­ments. One of these is ris­ing tem­per­a­tures. In addi­tion to its impact on the ecosys­tem, this phe­nom­e­non has seri­ous con­se­quences for men­tal health. High tem­per­a­tures are asso­ci­at­ed with high­er rates of sui­cide, but also of psy­chi­atric hos­pi­tal­i­sa­tion. “There is an approx­i­mate 1% increase in sui­cide rates for every 1°C increase in tem­per­a­ture above a spe­cif­ic thresh­old for each geo­graph­i­cal area,” says Jes­si­ca New­ber­ry Le Vay. Peo­ple who suf­fer from men­tal ill­ness, par­tic­u­lar­ly psy­chosis, demen­tia, or addic­tion, are two to three times more like­ly to die dur­ing heat­waves than peo­ple with­out men­tal health prob­lems, the Grantham Insti­tute report says. In addi­tion, there is also an increase in con­flict, vio­lence – espe­cial­ly domes­tic vio­lence – and assaults. “The gen­er­al lev­el of well-being is falling,” says Susan Clayton.

While we don’t yet know exact­ly why heat has these effects, there are some pos­si­ble expla­na­tions. High tem­per­a­tures dis­rupt sleep, which is an essen­tial com­po­nent of men­tal health. Tem­per­a­ture changes can also cre­ate phys­i­o­log­i­cal changes, affect­ing blood flow and the ner­vous sys­tem, which will have cog­ni­tive and emo­tion­al impacts, the Grantham Insti­tute argues. 

Extreme weather events cause climate “trauma”

Cli­mate change affects pop­u­la­tions indi­rect­ly, through aware­ness of its effects, through the con­se­quences on ter­ri­to­ries, through the threat to food, eco­nom­ic or hous­ing secu­ri­ty. “These are stress fac­tors that can lead to psy­cho­log­i­cal prob­lems,” says psy­chol­o­gist Susan Clay­ton. Cli­mate change also dam­ages peo­ple’s phys­i­cal and men­tal health direct­ly, through extreme weath­er events, which are observed in all regions of the world. Fires, hur­ri­canes, and floods are on the rise, and the IPCC expects these events to increase as warm­ing pro­gress­es. Many researchers have looked at the psy­cho­log­i­cal effects of these dis­as­ters. Susan Clay­ton reviewed this lit­er­a­ture for the IPCC report. The most com­mon symp­toms are post-trau­mat­ic stress, anx­i­ety, depres­sion, increased stress, feel­ings of grief, bereave­ment, and uncer­tain­ty about the future. 

As of 2019, the term cli­mate trau­ma refers to the psy­cho­log­i­cal dis­tress caused by envi­ron­men­tal destruc­tion. Jyoti Mishra, a pro­fes­sor of psy­chi­a­try at the Uni­ver­si­ty of Cal­i­for­nia San Diego, spe­cial­is­ing in neu­ro­science and men­tal health, is work­ing on the dead­liest fire in California’s his­to­ry, the Camp Fire. Occur­ring from 8th-26th Novem­ber 2018, the fire rav­aged 620 km2 of for­est, and destroyed the town of Par­adise. Its first study quan­ti­fied the num­ber of peo­ple who report­ed trau­ma. The num­ber of symp­toms such as post-trau­mat­ic stress, depres­sion or anx­i­ety was two to three times high­er in peo­ple who had expe­ri­enced the fire, com­pared to those who had not been exposed to it.

Cognitive damage 

In Jan­u­ary this year, Jyoti Mishra pub­lished the first study to exam­ine the neu­ro­log­i­cal and cog­ni­tive impacts of weath­er-relat­ed trau­ma. The aim is to deter­mine whether brain func­tion is affect­ed by expo­sure to an extreme weath­er event. 75 peo­ple took part in the study six to twelve months after the fire. Of these, 27 were direct­ly exposed to the fire either through the destruc­tion of their home or the loss of a loved one; 21 were indi­rect­ly exposed as they wit­nessed the fire but were not per­son­al­ly affect­ed; and 27 were not exposed at all. 

Cog­ni­tive tests were devel­oped to analyse the men­tal process­es involved in mem­o­ry, learn­ing, think­ing and inter­fer­ence pro­cess­ing, i.e. the abil­i­ty to ignore dis­trac­tions. “For an hour, indi­vid­u­als were giv­en these tests to focus their atten­tion on some­thing, to make their mem­o­ry work. All brain activ­i­ty was record­ed with an elec­troen­cephalo­gram,” the psy­chi­a­trist explains. “These tests were cho­sen because they are at the heart of human cog­ni­tive abil­i­ties, and they have been shown to be impor­tant abil­i­ties in the con­text of trau­ma, depres­sion or men­tal health problems.”

To observe inter­fer­ence pro­cess­ing, par­tic­i­pants were asked to focus on an object in the mid­dle of a screen, such as a fish, and say whether it was point­ing left or right. Mean­while, oth­er objects appeared on the screen. Those exposed to the fires, both direct­ly and indi­rect­ly, had 20% less accu­rate respons­es than the con­trol group. This meant that they were more dis­tract­ed and had more dif­fi­cul­ty con­cen­trat­ing on a task.

Peo­ple exposed to fire have more dif­fi­cul­ty con­cen­trat­ing on a task.

“In addi­tion, we found greater frontal and pari­etal brain activ­i­ty for the direct­ly exposed group. This means that the brain is mak­ing more effort to func­tion, to stay focused and atten­tive,” says the study author. “This can be com­pared to the expe­ri­ence of peo­ple suf­fer­ing from post-trau­mat­ic stress dis­or­der, who become very aware and atten­tive to their envi­ron­ment, and pay atten­tion to every­thing because every­thing seems like a threat.”

For Jyoti Mishra, it is very impor­tant to devel­op sim­i­lar research to under­stand the effects of cli­mate trau­ma on our brain, on our biol­o­gy. These results can help nor­malise these symp­toms and devel­op more appro­pri­ate treat­ments. But are these cli­mate-relat­ed psy­cho­log­i­cal expe­ri­ences spe­cif­ic to oth­er prob­lems already iden­ti­fied, such as post-trau­mat­ic stress dis­or­der? “We don’t know at the moment. It seems that there are dif­fer­ences in the symp­toms, but also in the best way to treat them ther­a­peu­ti­cal­ly. We are still in the ear­ly stages, and we need more research,” says Susan Clayton. 

Inequalities in the psychological impacts of climate change

What has been wide­ly doc­u­ment­ed by research is that we are not all equal when it comes to cli­mate change-relat­ed men­tal health prob­lems. Peo­ple who are already vul­ner­a­ble in soci­ety are even more like­ly to devel­op prob­lems. “This is because of the resources avail­able to cope with these events, includ­ing prac­ti­cal resources such as air con­di­tion­ing, shel­ter, and eco­nom­ic and social resources,” says the Amer­i­can psy­chol­o­gist. Some groups are more affect­ed, such as the eco­nom­i­cal­ly dis­ad­van­taged, chil­dren, the elder­ly and women. 

So, what can be done to mit­i­gate these psy­cho­log­i­cal impacts? In addi­tion to devel­op­ing research on these sub­jects, to refine treat­ments, spe­cial­ists agree on the need to increase the resources allo­cat­ed to men­tal health. “We need to pro­vide peo­ple with emo­tion­al tools and cre­ate sup­port and assis­tance net­works for peo­ple who have expe­ri­enced dis­as­ters,” say Susan Clay­ton and Jes­si­ca New­ber­ry Le Vay. It is also pos­si­ble to act upstream to avoid these impacts, by devel­op­ing eas­i­er access to nature and safe hous­ing, and by strength­en­ing safe social ties.

Sirine Azouaoui 

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