If any of my blog posts are bad, it’s because of climate change making my brain not think good.

Well, maybe not. Still, there’s been some research into how the changes we’re causing to the planet’s surface may affect our cognitive ability. The first stuff I saw on this had more to do with heat waves. Simply put, when the weather is hotter than we are used to or comfortable with, it impairs the function of our built-in meat computers:

Students who lived in dormitories without air conditioning (AC) during a heat wave performed worse on a series of cognitive tests compared with students who lived in air-conditioned dorms, according to new research led by Harvard T.H Chan School of Public Health. The field study, the first to demonstrate the detrimental cognitive effects of indoor temperatures during a heat wave in a group of young healthy individuals, highlights the need for sustainable design solutions in mitigating the health impacts of extreme heat.

Now to add to this, we have research indicating that by the end of the century, elevated global CO2 levels could combine with poorly designed buildings to result in high enough concentrations to impair cognitive function, in some enclosed spaces.

“It’s amazing how high CO2 levels get in enclosed spaces,” said Kris Karnauskas, CIRES Fellow, associate professor at CU Boulder and lead author of the new study published today in the AGU journal GeoHealth. “It affects everybody — from little kids packed into classrooms to scientists, business people and decision makers to regular folks in their houses and apartments.”

Shelly Miller, professor in CU Boulder’s school of engineering and coauthor adds that “building ventilation typically modulates CO2 levels in buildings, but there are situations when there are too many people and not enough fresh air to dilute the CO2.” CO2 can also build up in poorly ventilated spaces over longer periods of time, such as overnight while sleeping in bedrooms, she said.

Put simply, when we breathe air with high CO2 levels, the CO2 levels in our blood rise, reducing the amount of oxygen that reaches our brains. Studies show that this can increase sleepiness and anxiety, and impair cognitive function.

We all know the feeling: Sit too long in a stuffy, crowded lecture hall or conference room and many of us begin to feel drowsy or dull. In general, CO2 concentrations are higher indoors than outdoors, the authors wrote. And outdoor CO2 in urban areas is higher than in pristine locations. The CO2 concentrations in buildings are a result of both the gas that is otherwise in equilibrium with the outdoors, but also the CO2 generated by building occupants as they exhale.

Atmospheric CO2 levels have been rising since the Industrial Revolution, reaching a 414 ppm peak at NOAA’s Mauna Loa Observatory in Hawaii in 2019. In the ongoing scenario in which people on Earth do not reduce greenhouse gas emissions, the Intergovernmental Panel on Climate Change predicts outdoor CO2 levels could climb to 930 ppm by 2100. And urban areas typically have around 100 ppm CO2 higher than this background.

Karnauskas and his colleagues developed a comprehensive approach that considers predicted future outdoor CO2 concentrations and the impact of localized urban emissions, a model of the relationship between indoor and outdoor CO2 levels and the impact on human cognition. They found that if the outdoor CO2 concentrations do rise to 930 ppm, that would nudge the indoor concentrations to a harmful level of 1400 ppm.

The idea that we could end up with outdoor CO2 levels at 930ppm is, frankly, horrifying, and seems over the top, at a gut level. That said, the current level is 414ppm, and while the rate of human CO2 emissions has slowed a bit, we’re still adding HUGE amounts to the atmosphere every year, and the warming we’ve seen so far is both interfering with natural CO2 sinks’ ability to pull the stuff out of the air, and is causing the permafrost to thaw, rot, and release even more CO2 and methane.

930ppm, unfortunately, is not out of the question, and with the general consensus that 350ppm is the “safe” maximum we should be aiming for, it’s not good news that by the end of the century, we could be facing not just apocalyptic levels of warming, but also changes to the atmosphere sufficient to mess with our ability to think, which is the primary tool we have to survive in an increasingly hostile world.

At this point I think it’s unlikely that we’ll stop warming in that time frame, partly because of what has already been set in motion, and partly because while some countries are starting to take the issue seriously, it’s nothing like the scale we need to actually deal with the problem. That means that as we work to mitigate this threat, we also need to be working to redesign our society to be better able to cope with it. No adaptation strategy will be effective or sufficient without dealing with greenhouse gas emissions, but making massive, global, systemic changes to how our societies operate will be a lot harder if we’re constantly recovering from one avoidable catastrophe after another.

My regular readers will be shocked to hear that I don’t see how we’re going to be able to take the action needed while the global economy is still almost entirely centered around generating profits for a vanishingly tiny fragment of the population. Relocating cities or redesigning them to function as sea levels rise will not be profitable. Ensuring that everyone, regardless of personal wealth, has access to air conditioning not powered by fossil fuels will not be profitable. Building nuclear power that is both able to withstand unprecedented heat waves, droughts, floods, and storms, and that won’t be mismanaged for the sake of cutting costs and increasing profits, will not be profitable. Building widespread renewable power, and widespread power storage that meets our needs will not be profitable. Re-designing the global agricultural system to continue producing food in a rapidly warming climate will not be profitable.

Or if any of these are profitable, those profits will come at the cost hundreds of millions of lives – a cost I think is far too high to justify. Just as placing profits over human life is resulting in disaster as we try to cope with the COVID-19 pandemic, doing so is already causing huge amounts of damage through environmental destruction and a warming climate. We need to change how we operate, and we need to do it fast.

Hey everybody, I am once again asking for your assistance. I really need help paying my bills and keeping a roof over my head. Patreon.com is a way for you to help with that, even if it’s just a little bit, and get some perks and extra content in return. You control how much you give, and how long you give it, and every little bit really does help. When lots of people pitch in, it can make a huge difference. Please help if you’re able, and share my work with others. Thank you!


  1. StevoR says

    Tangential but I gather that hotter conditions cause or contribute to more aggression and poorer judgement generally – see :


    Excerpt :

    A growing body of evidence shows that rapid global warming can (and is) increasing violent behavior in three different ways. When people get uncomfortably hot, their tempers, irritability, and likelihood of physical aggression and violence increase. This is perhaps best demonstrated in a series of laboratory studies conducted by APS Fellow Craig A. Anderson and his colleagues .. (snip) .. he researchers conclude, based on the collection of studies, that uncomfortably hot temperatures increase aggression. Although laboratory forms of aggression may seem trivial, other studies illustrate the deadly implications of these findings. ..(snip) .. Numerous cross-sectional and time-series studies using real-world heat and violence data provide converging evidence. Cities and regions with higher temperatures tend to experience more violent crime than cooler regions, even after controlling for a dozen sociocultural factors such as age, race, poverty, and culture of honor. Further ruling out alternative explanations, some studies have assessed temperature and violence within the same geographic region over time. Across hours, days, months, and even years, similar trends emerge: When it is hotter, violence increases. From Chicago to Brisbane to Vancouver to Dallas, whether looking at domestic violence or physical assault, the same relationship emerges.

    Plus a study here from my own home town (no I wasn’t one of the subjects!) :


    Above a threshold of 26.7 degrees C, ( 80.06 F -Ed) we observed a positive association between ambient temperature and hospital admissions for mental and behavioral disorders. Compared with non-heat-wave periods, hospital admissions increased by 7.3% during heat waves. Specific illnesses for which admissions increased included organic illnesses, including symptomatic mental disorders; dementia; mood (affective) disorders; neurotic, stress related, and somatoform disorders; disorders of psychological development; and senility. Mortalities attributed to mental and behavioral disorders increased during heat waves in the 65- to 74-year age group and in persons with schizophrenia, schizotypal, and delusional disorders. Dementia deaths increased in those up to 65 years of age.

    In addition to :


    In fact, hot and especially humid weather is known to be associated with increases in aggression and violence, as well as a lower general mood, Molitor said.

    That’s because trouble sleeping, dehydration and restrictions on our daily actives — such as being cooped up inside all day to avoid the sweltering heat — may all contribute to a worsening mood in warm weather, Molitor said. And a lack of control over the situation may further irritate some people, she said.

    Amiong other similar studies and articles. basically, hotter weather esp and increasing post about 27 Celsius (80 F) is really bad for us mentally and, of course, we’re going to expect more prolonged and more extreme periods of such temperatures.

  2. says

    Thanks for the additions!

    Yeah, there are a lot of ways in which the rise in temperature is going to cause mental health problems.

    It’s also going to make air pollution more aggressive, which in turn also affects mental health:

    I’ll be writing more about this soon, but it really does seem like the only way to avoid a hellish future is to embrace some form of democratic socialism centered around human and environmental health.

    Things like reducing pollution, increasing greenery, and reducing workloads from their current profit-driven highs will be necessary to avoid serious, escalating societal problems across the board.

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