What are the psychological impacts of climate change?

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.” 

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. 

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 8^th-26^th 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.

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. 

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