Brains, Evolution, Climate

as studied by William H. Calvin, professor emeritus, University of Washington


William H. Calvin:  Hello.  Yes, I know that Brains, Evolution, and Climate sound like three very different subjects. What ties them together for me is that they are all prime examples of a complex dynamical system, ones where history matters (in classical thermodynamics, it doesn't). They are also full of surprises, where something new springs into action once a threshold is crossed.

Besides being president of the CO2 Foundation, I am an emeritus professor at the University of Washington's School of Medicine in Seattle, with a Ph.D. in physiology and biophysics following an undergraduate physics major.  I have written seventeen books for general readers on brains, human evolution, and climate shifts, translated into sixteen other languages. 

For 40 years, I have had a ringside seat for the climate scientists’ analysis of global warming and, having learned to write about complicated science for general readers on brain topics and then evolution's dynamics, I undertook to do it for climate science.  

That’s how I came to write about both the ascent of human intelligence and the collapse of civilization if we fail to quickly repair climate. Though nominally a neuroscientist working on the brain's circuitry and evolution, I was asked to write the first major magazine article on abrupt climate change back in 1998, a cover story for The Atlantic called "The Great Climate Flip-flop." The latest on that subject is "Rethinking Climate: Starting a Second Front in the Climate War."

Because our ancestors’ brain enlargement and toolmaking abilities didn’t markedly increase until the ice ages began, 2-3 million years ago, I started paying attention to the mechanisms of climate change and how they might interact with human evolution to promote some of the uniquely human attributes such as planning ahead and nested syntax.

The 2016 surprise from my work on the evolution of big brains: there is a feedback loop triggered by lightning strikes.  Bush fire boom-and-bust occurs far more often than does climate change, and it promotes trait hitchhiking in our meat-loving ancestors.  Some functions can evolve without having to pay their own way. I had to set aside the unpublished manuscripts in 2018 when I realized how serious the extreme weather surges had become.

Supplementary (i.e., old) home pages

They are full of links that I have not yet incorporated into this 2021 homepage version.


Brains, Evolution, and Climate

Pre-2008, with fragments of my first webpage in 1994

It's not necessarily so.

There are effective actions we can still take to repel the extreme weather invasion, if we only get our act together in a hurry. 

Like war, it is risky—but properly focused actions can greatly improve our chances. 

The trip to 'hell' is not a sure thing. 

--from the conclusion of Extreme Weather
(and What to Do About It)

Using an Emergency Medicine Mindset to Guide Climate Action

 for the 2020 American Geophysical Union's Fall Meeting. 

HERE I WILL ILLUSTRATE how the emerg­ing climate crisis would be viewed by those in the medical comm­un­ity who are used to dealing with fuzzy categories and their closing windows of opportunity. I hope to provide a better intellectual toolkit for facing up to the climate crisis, largely borrowed from what medical school professors teach about dealing with emergencies.

Here, climate emergency” is not the usual rhetorical exaggeration of needed and urgent. To speak of an emergency, one means an unexpected dangerous situation—one that requires immediate action as there is a closing window of opportunity for taking effect­ive action.


Climate urgency became a climate emergency a decade ago, but we have only recognized that in retrospect when the new extremes were sustained. For example, the annual number of severe inland windstorms is up 00% after 2008. In the same way that we would organize to deflect a meteor strike in 2030, we must act on the climate emergency.

Gradual overheating is no longer the correct focus for under­standing the risk we now face, as we have entered the territory where faster tracks to disaster must be forestalled. In relying exclus­ively on an emissions reduction strat­egy, we have been “betting the farm” on some­thing that will not do the job in time. We must add a carbon removal strategy—very quickly.

However logical it seems to tackle the root cause, burning fossil fuels, it is no longer the most immediate problem we face. We now have fast-moving secondary problems, such as the extreme weather shifts.

As in medicine, one must first head off the immediate threats—and then educate the patient about preventing a recurrence. The important response to a dental abscess is not a prevention measure, such as cutting down on sugary drinks. It is stopping the infection from “going systemic” and killing the patient.

We now need a paradigm shift away from focusing on the next fractional-degree temperature rise (merely reducing CO₂ annual emissions, rather like cutting back to one pack per day) to a new focus on the extreme weather shifts.

They require removing enough excess CO₂ to actually cool us back to the global mean surface temperatures of the 1960s. But a buying-time strategy may also be needed to reduce extreme weather during CO₂ removal project, and one candidate is more quickly cooling the high Artic with clouds or high haze.

...Continues with Emissions...

Where are we are going?


Four half-hour talks

“The climate crisis has been a lot to wrap our hearts, heads, and strategic policy around. However, climate urgency took a big step up a decade ago as extreme weather surged and stayed. 

We have been “betting the farm” on emission reductions, which will not do the job in time. We now need a big CO2 cleanup before we miss even more exits on the Freeway to Hell.”  --WHC

A Carbon Diet is too Slow.  "We now need a paradigm shift, away from focusing on the next fractional-degree temperature rise (merely reducing CO₂ annual emissions, rather like cutting back to one pack per day), to a new focus on backing out of the extreme weather shifts with CO2 removal.


The Wrong Target can be Dangerous.  "When we assume that emissions reduction is still the appropriate target for responding to the Climate Problem, as our leaders do, we not only fail to acknowledge the urgency of cooling things off but we set the stage for misguided responses--say, quickly reducing the world's population in order to reduce emissions. It seems only a matter of time before someone offers emissions reduction as an excuse for genocide, or for not intervening in a pandemic. 

That would not do a thing for the overhead accumulation of carbon dioxide and other heat-trapping gases in the near term, and thus little towards cooling us before extreme weather destroys the global economy and our ability to save civilization via a Big Project.  


My two cover stories serve to illustrate how I became interested in global overheating and climate dynamics.