Changing Climate, Changing Brains

June 10, 2025

Written by Margaret Gardner

When you think about the negative consequences of climate change¹, you probably see lonely polar bears floating on tiny icebergs or time-lapse footage of plants dying in a drought. Well, I’ve got some more bad news for you: neuroscientists are becoming increasingly concerned about the heating planet’s impact on our brains. Some good news, though: they’re also starting to explore why some people behave in more environmentally friendly ways and how best to encourage others to do the same. Bear with me as we unpack the ways climate change is harming our brains, both directly and indirectly. And stay tuned for my next article in November, where I’ll talk about how neuroscientists are fighting back.

Rising Temperatures

The brain is responsible for keeping itself (and the rest of the body) within a safe temperature range; and usually, it does a very good job. However, climate change is causing more frequent and serious heatwaves^2,3 – as well an overall temperature increase worldwide⁴ –  putting pressure on this temperature-regulating system. This increases the risk for developing neurological and psychiatric disorders and may make symptoms of existing conditions – everything from multiple sclerosis and epilepsy to schizophrenia and Alzheimer’s – more likely to flare up^5–7. For example, evidence suggests that when your cooling system is on overdrive from excessive sweating or changes in blood flow, risk for stroke increases⁵. Meanwhile, higher brain temperatures also disrupt communication between cells, which can trigger seizures⁵. Finally, anyone who’s camped outside on a humid summer’s night can tell you that heat makes it harder to get a good night’s sleep. Your brain needs sleep to do important maintenance, clearing waste and lock-in memories. Therefore, sleep deprivation is another way that unusually high temperatures increase the risk for chronic conditions like Alzheimer’s⁵. We still don’t know all the ways that temperature spikes above what people in a given climate are used to put stress on – and ultimately harm – brain function. However, a growing number of studies are showing a link between hotter temperatures and an increased risk and severity of neurological and psychiatric diseases^6,8,9.

Extreme weather

In addition to raising temperatures overall, climate change is making weather patterns more drastic and unpredictable, triggering more devastating natural disasters. Climate-change-induced catastrophes, like living through a tornado or having your home destroyed by a flood, sharply increase one’s risk of post-traumatic stress disorder (PTSD) and depression^8,10. The negative impact of these traumatic experiences can even echo into future generations. People who were exposed to trauma in utero (as a fetus) may be more likely to suffer a range of difficulties with mood, problem-solving, and attention¹¹. Even far-future generations could be impacted, since recent research shows people who’ve experienced trauma can pass down genetic changes that put their descendants at higher risk for unhealthy stress responses and PTSD^12,13. Unfortunately, less serious weather events can still have harmful effects. Scientists have already recognized that drastic changes in weather, such as changing seasons, affect our moods. Bad weather can cause people to stay indoors, where they’re more likely to be isolated and miss out on the brain- and mood-boosting benefits of nature and social connections¹⁰. Therefore, by causing extreme weather, climate change increases the risk that any given person is exposed to trauma and all its unpleasant neuropsychiatric damage, both directly and by way of their ancestors.

Changing habitats

When it comes to wildlife, many of us worry about climate change causing extinction. Unfortunately, neuroscientists are also worried about creatures that are able to adapt to global temperature shifts and thrive under these conditions, because many of them carry viruses with serious neurological symptoms. Higher temperatures and humidity have already allowed ticks to start spreading beyond their traditional habitats, bringing Lyme disease with them⁹; similar outcomes are expected for mosquito-borne diseases like Zika and West Nile virus⁹. All in all, scientists expect global warming to change the habitats of virus-carrying creatures, making pandemics more common and geographically widespread⁶.

Air pollution

Climate change and air pollution are strongly linked: climate change makes air pollution worse, while many activities that drive climate change, like burning coal, create air pollution^14,15. While many of us know that poor air quality can damage our health, you might be surprised to learn just how much it can harm the brain. Studies using MRI to scan the brain found that people exposed to poor air quality tended to have a less brain tissue in the brain area responsible for memory, which is called hippocampus⁸. They also had sharper decreases in the insulation that allows neurons to send electrical signals to one another⁶, Research tracking health across large groups of people has linked common air pollutants to strokes, headaches, Parkinson’s disease, and even problems with cognition and social function^6,8. Overall, the current research suggests that air pollution will worsen both climate change and its effects on our brains.

Stress and anxiety

How do you feel reading this article? Stressed? Hopeless?* Doctors and scientists have recently started to use the term ‘climate anxiety’ to refer to the chronic stress, fear, and helplessness many feel when considering climate change and little society seems to be doing about it^9,16.  Feeling some degree of anxiety about climate change is common⁹, particularly among children and young adults¹⁷. Many psychologists agree that it makes sense to be anxious about climate change and all the destruction it will bring^17,18, but the trick is figuring out how to help individuals cope with their climate anxiety in a healthy way, without sticking one’s head in the sand. Currently, a strong approach seems to be channeling anxiety about climate change into environmental action that 1) helps the planet and 2) relieves anxiety by giving people a sense of empowerment^10,17,18. Like the rest of climate change and its consequences, however, this is still a very active area of research, which I’ll discuss more in my next article.

Each of the factors described above are bad enough on their own. However, they will be even more harmful to those who’s brains are already under stress from things like neurological diseases, mental illnesses, medications that impact temperature regulation, age, poverty, and/or pregnancy⁵.In addition to all the other bad stuff it’s doing, climate change will cause more people to experience more severe neurological and psychiatric conditions- and those already living with neuropsychiatric symptoms will be some of the hardest hit.

Clearly, it’s not looking good. However, humans created climate change and humans will have to stop it, which means that a better understanding of human cognition and behavior could go a long way in helping us get there. More and more neuroscientists are using their scientific resources to call attention to this under-explored field, and to push for more environmentally-friendly practices in every area of research¹⁰. Stay tuned for what I promise will be a much more uplifting article in November, and in the meantime, check out some of the resources below.

*Feeling anxious? Check out these resources:

• “Resources for Coping with Climate Anxiety” from Yale University’s Office of Sustainability: https://sustainability.yale.edu/blog/resources-coping-climate-anxiety
• “Actions for a healthy planet” recommended by the United Nations: https://www.un.org/en/actnow/ten-actions
• “Climate Justice Organizations” list curated by the Bentely University Library: https://libguides.bentley.edu/ClimateJustice/Organizations 
• A list of high-impact climate-activist organizations, curated by Vox: https://www.vox.com/future-perfect/2019/12/2/20976180/climate-change-best-charities-effective-philanthropy

References

1.             United Nations. What Is Climate Change? United Nations. Accessed June 1, 2025. https://www.un.org/en/climatechange/what-is-climate-change

2.             US EPA O. Climate Change Indicators: Heat Waves. February 4, 2021. Accessed June 8, 2025. https://www.epa.gov/climate-indicators/climate-change-indicators-heat-waves

3.             Marx W, Haunschild R, Bornmann L. Heat waves: a hot topic in climate change research. Theor Appl Climatol. 2021;146(1-2):781-800. doi:10.1007/s00704-021-03758-y

4.             Nations U. Causes and Effects of Climate Change. United Nations. Accessed June 8, 2025. https://www.un.org/en/climatechange/science/causes-effects-climate-change

5.             Gulcebi MI, Leddy S, Behl K, et al. Imperatives and co-benefits of research into climate change and neurological disease. Nat Rev Neurol. 2025;21(4):216-228. doi:10.1038/s41582-024-01055-6

6.             Louis S, Carlson AK, Suresh A, et al. Impacts of Climate Change and Air Pollution on Neurologic Health, Disease, and Practice. Neurology. 2023;100(10):474-483. doi:10.1212/WNL.0000000000201630

7.             Liu J, Varghese BM, Hansen A, et al. Is there an association between hot weather and poor mental health outcomes? A systematic review and meta-analysis. Environ Int. 2021;153:106533. doi:10.1016/j.envint.2021.106533

8.             Todorova B, Steininger MO, Lamm C, Doell KC. Neuroscience and climate action: intersecting pathways for brain and planetary health. Curr Opin Behav Sci. 2025;63:101522. doi:10.1016/j.cobeha.2025.101522

9.             Sisodiya SM, Gulcebi MI, Fortunato F, et al. Climate change and disorders of the nervous system. Lancet Neurol. 2024;23(6):636-648. doi:10.1016/S1474-4422(24)00087-5

10.          Doell KC, Berman MG, Bratman GN, et al. Leveraging neuroscience for climate change research. Nat Clim Change. 2023;13(12):1288-1297. doi:10.1038/s41558-023-01857-4

11.          Nomura Y, Newcorn JH, Ginalis C, et al. Prenatal exposure to a natural disaster and early development of psychiatric disorders during the preschool years: stress in pregnancy study. J Child Psychol Psychiatry. 2023;64(7):1080-1091. doi:10.1111/jcpp.13698

12.          Babenko O, Kovalchuk I, Metz GAS. Stress-induced perinatal and transgenerational epigenetic programming of brain development and mental health. Neurosci Biobehav Rev. 2015;48:70-91. doi:10.1016/j.neubiorev.2014.11.013

13.          Khan Z, Messiri NE, Iqbal E, et al. On the role of epigenetic modifications of HPA axis in posttraumatic stress disorder and resilience. J Neurophysiol. 2025;133(3):742-759. doi:10.1152/jn.00345.2024

14.          US EPA O. Climate Change Impacts on Air Quality. October 19, 2022. Accessed June 2, 2025. https://www.epa.gov/climateimpacts/climate-change-impacts-air-quality

15.          Air Quality and Climate Change | Center for Science Education. Accessed June 2, 2025. https://scied.ucar.edu/learning-zone/air-quality/air-quality-and-climate-change

16.          Hanife B, Cianconi P, Grillo F, Paulinich A, Janiri L. Climate anxiety as a call to global justice. Front Psychol. 2025;16:1547678. doi:10.3389/fpsyg.2025.1547678

17.          Clayton S. Climate anxiety: Psychological responses to climate change. J Anxiety Disord. 2020;74:102263. doi:10.1016/j.janxdis.2020.102263

18.          Boehme BAE, Kinsman LM, Norrie HJ, Tessier ED, Fleming SW, Asmundson GJG. Climate Anxiety: Current Evidence and Future Directions. Curr Psychiatry Rep. 2024;26(11):670-677. doi:10.1007/s11920-024-01538-9

 Cover image by HoAnneLo from Pixabay.