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