Warming Doesn't Just Melt Glaciers — It Reshapes Your Brain's Decisions
The brain is a statistical model of the environment, and climate is the human-set baseline for normal. When the baseline itself moves, forgetting becomes an adaptation mechanism — you slide into treating the abnormal as normal without noticing.
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The brain is a statistical model of the environment, not a hard drive
Aldern defines the brain as ‘a statistical model of the environment’ — a generative model that lets an organism represent the external world and navigate it successfully. The model's core function is to measure the gap between expectation and actual perception. When a gap appears, the organism has only two paths: update the model to match perception, or take action to change perception. This ‘action-perception loop’ is the foundation for understanding every climate effect that follows. Climate anxiety is only the surface; the real problem is that the model itself is being reshaped by environmental change.
— Clayton Page AldernClimate doesn't exist — it's just a cultural construct
Aldern makes a counterintuitive claim: climate is not an entity you can reach out and touch. A raindrop landing on your hand is real, but that's weather. Climate is ‘the definition of normality for any given point in time and space’, a human-constructed average — the World Meteorological Organization defines it as a 30-year, 10-kilometer-by-10-kilometer average. In other words, climate is expectation itself. If the brain's core function is to calibrate expectation against perception, and climate as expectation is changing, then your nervous system must change along with it.
— Clayton Page AldernForgetting is an adaptation mechanism, not a cognitive defect
If the brain is a model and climate is expectation, what happens when the expectation itself is moving? Aldern's answer: forgetting. If you remembered every climatic past, you couldn't adapt to the new world. So ‘we ought to forget what the world currently is not, in order to successfully navigate the new world’. This produces a paradox: a voice in your ear whispering ‘it's always been like this, this is the definition of normal’. The battle over climate therefore has two fronts — the external physical world, and the external world's remodeling of your internal representation.
— Clayton Page AldernHeat unbalances the prefrontal cortex, and vmPFC takes over decisions
From the heated telegraph operators in a 1940s Cambridge lab to the psychology labs of the 1980s, research has consistently found that under high heat people are more impulsive, less rational, and less capable of critical thinking. The mechanism is that brain tissue is extremely sensitive to temperature and must burn extra metabolic energy to cool down. That crowds out a fixed pool of attentional resources. Concretely in neuroscience terms: the dorsolateral prefrontal cortex (DLPFC) handles critical thinking, while the ventromedial prefrontal cortex (vmPFC) receives emotional input from the amygdala and elsewhere. In a healthy environment the two are balanced; under extreme heat the DLPFC overloads, the vmPFC takes over, and decisions become impulsive.
— Clayton Page AldernHeat increases violence: from honking to retaliatory hit-by-pitches
Researchers in the 1980s hid in bushes to observe how the car behind reacted when the car in front didn't move after the light turned green. In hot weather, especially in vehicles with open windows (suggesting no air conditioning), honking increased, horn presses lasted longer, and drivers were more likely to swear. The effect extends into professional domains: baseball pitchers are more likely to throw retaliatory pitches in high heat; a Harvard economist's study of harassment complaints in the postal system found that the hotter it was, the more harassment occurred, for both indoor and outdoor workers. Online hate speech, domestic violence and interpersonal violence all rise with relative temperature deviation.
— Clayton Page AldernBlue-green algal neurotoxins may travel through the air
Cyanobacteria produce the neurotoxin BMAA, known to be associated with ALS, Parkinson's and Alzheimer's. The new finding is that BMAA may spread via aerosols, so people living around lakes can be exposed too. Warming drives cyanobacterial blooms from three directions: synthetic fertilizer runoff balances the nitrogen-to-phosphorus ratio, warmer water temperatures, and extreme storms washing more fertilizer into rivers. Globally, cyanobacterial blooms are increasing in both scale and frequency. Aldern warns: if cyanobacteria are everywhere on a global scale, they could cause serious damage in the coming decades.
— Clayton Page AldernIn utero through a hurricane, tenfold depression risk at age six
Research on the Paradise fire shows PTSD risk stratification: people who neither lost property nor directly experienced the fire were basically normal; those who knew someone who lost property or witnessed the event had about triple the PTSD rate; those who themselves lost property or family members had triple that again. After Hurricane Katrina, roughly half of low-income parents had PTSD symptoms. More striking still is Yoko Nomura's research on Hurricane Sandy: children who experienced the hurricane in utero were ten to twenty times more likely than the unexposed group to show anxiety, depression, OCD, ADHD and other cognitive-behavioral deficits by age six. Aldern believes this hints at epigenetic mechanisms at work.
— Clayton Page AldernAll neural climate effects are still sitting on the shelf, outside policy
Aldern points to a key gap: a few intergovernmental bodies now seriously consider climate change and health, but large climate policy cost-benefit analyses rarely incorporate those organizations' recommendations. No climate-and-health literature has attempted to price the presenteeism and absenteeism caused by rising temperatures in the workplace. All the neural effects discussed ‘are sitting on the shelf, existing in conversations like this one, but they haven't yet become part of the policy-making infrastructure’. He argues that awareness at the societal level means integrating well-understood research into the actual decision protocols for governing climate change.
— Clayton Page AldernIn their own words · checked verbatim
there's no real thing as the climate. The climate doesn't exist in the sense that we can put our hand out there and touch it.
Clayton Page Aldern11:01
we ought to be forgetting the ways that the world currently isn't if we want to navigate the new world successfully
Clayton Page Aldern13:05
As the DLPFC is overworked, the vmPFC effectively takes over and in practice for decision making. What does that mean, Well, it means your decisions are going to look more impulsive. You will literally be a less critical thinker.
Clayton Page Aldern19:19
you kind of can't get that cross generational trauma transfer without the physical mechanism
Clayton Page Aldern35:50
All of the neurological effects that we've discussed thus far, they're sitting on a shelf. They're sitting in conversations like these, but they are not part of the policy making infrastructure yet.
Clayton Page Aldern40:54
Climate change is really good at stealing agency. I think what the awareness story gives us back is a little bit of control
Clayton Page Aldern41:56
Figures
| Time scale of the climate definition | 30 years | 12:03 |
| Spatial scale of the climate definition | 10 kilometers by 10 kilometers | 12:03 |
| Survival time after Naegleria fowleri infection | about 5 days | 29:42 |
| PTSD risk multiple for people who knew victims in the Paradise fire | about 3x | 32:45 |
| PTSD risk multiple for people who directly lost property or family in the Paradise fire | 3x higher again | 32:45 |
| Share of low-income parents with PTSD symptoms after Hurricane Katrina | about half | 33:47 |
| Depression risk multiple at age six for children who experienced Hurricane Sandy in utero | 10 to 20x | 34:50 |
Glossary
- BMAA / β-methylamino-L-alanine
- A neurotoxin produced by cyanobacteria, associated with ALS, Parkinson's and Alzheimer's.
- DLPFC / dorsolateral prefrontal cortex
- The brain region responsible for critical thinking and rational decision-making, prone to overload under high heat.
- vmPFC / ventromedial prefrontal cortex
- The brain region receiving emotional and impulsive input, which takes over decision-making when the DLPFC overloads.
- Naegleria fowleri
- Commonly known as the brain-eating amoeba; it enters the brain through the nasal cavity, and the death rate after infection is extremely high.
- presenteeism
- The phenomenon of employees being physically at work but underperforming because of health or cognitive problems.
How to listen
Founders, investors and policy researchers interested in the intersection of climate and cognition; managers assessing how climate risk affects organizational decisions and employee cognition.
The podcast intro and book recommendations from 0:43-4:54 can be skipped; go straight to 4:54 where the substance begins.