Can cleaner air push us over the climate cliff?  Special investigating air pollution: hidden warming, long-range damage with drought & rain – and to your health.  New science with Geeta Persad on missing climate risk of aerosols.  Followed by a replay of Leon Simons: termination shock of cleaning up air pollution.  Is it behind this year’s record-smashing heat?

Listen to or download this Radio Ecoshock show in CD Quality (57 MB) or Lo-Fi (14 MB)


“Globally, aerosols are a more powerful player in climate extremes than are greenhouse gases. Warm the world by removing aerosol emissions and this will create more extremely hot days, more extreme precipitation events, and more consecutive dry days over highly populated regions, than if the world was warmed by the same amount by adding greenhouse gases.”

– Persad et al. 2023

If we just talk about smog and heat, we miss one of the big stories of climate change. Most of the dialog about global warming has been about heat, rather than extreme rainfall and flood events. That is one reason why most scientists embrace the words “climate change” instead of “global warming”.

What if drought and rainfall changes are not just due to global warming?  What if it’s industrial pollution?  New science examines the role of airborne particles called “aerosols” as they change weather and lives around the world.  Aerosols are tiny bits of matter floating in the air, carried by the wind until they are rained out or drop to the surface again.  If you look for a blow-up photo of these specs, they look like tiny asteroids, irregular in shape and often full of holes.  That complex surface can be coated with toxic chemicals and even bacteria.

IMAGE SOURCE:  “Individual particle analysis of aerosols collected under haze and non-haze conditions at a high-elevation mountain site in the North China plain”.


There have always been dusty aerosols and even plant scent aerosols on Earth.  Your nose and lungs are designed to filter out and get rid of harmful particles.  But industrial processes, like diesel engines and power plants, create particles smaller than anything in Nature.  These bypass the human protection system, get through the lungs and into the blood stream.  From there, some even pass through the blood-brain barrier and the placenta, leading to brain or fetal damage and disease (See my Radio Ecoshock piece “The Polluted Womb” below).  That is why millions of people die every year from air pollution.  But now we learn they change the climate as well, hiding the real heating and altering rainfall around the world.  Welcome to breaking science on aerosols and the climate danger.

A 2021 study by scientists from Harvard and the UK found at least 8 million people died in 2018 due to emissions from fossil fuels alone.   In fact, a recent World Health Organization’s (WHO) study found, in the words of Issam Ahmed:

“Air pollution is more dangerous to the health of the average person on planet Earth than smoking or alcohol.”

Satellite maps show massive clouds of sulfates remain over China, India and much of Southeast Asia.  China, under pressure from citizens, and sensing mounting health costs, is pushing aggressively to reduce smog, especially in key cities like Beijing and Shanghai.  After killer smog in recent years, residents of New Delhi and Mumbai are calling for the same.  But what happens to the heat and rains if they succeed?

Aerosols can make changes of historic proportions, at this point likely greater than the impacts of greenhouse gases.  For example, a study found increasing pollution in Europe during the 1980’s led to a major long drought in the Sahel region of Africa.  Millions died of starvation, unaware that rain for crops was diverted by a smog further north in Europe.  And as the Persad-led study Abstract says:

Studies show that aerosols strongly affect the likelihood of extreme precipitation events, such as those that contributed to Pakistan’s floods, and many other climate hazards.

Our first guest led a new study with a whole different view on the world, one we seldom hear about: the real role of smog not just about our health, but in drought, rainfall, and extreme weather.


With global record heat this year, plus fires and dangerous floods – climate change and greenhouse gases have the spotlight.  But there is another way humans change the air and weather.  Every hour of every day smokestacks, cars, and homes pump tiny particles into the sky.  They are bits of chemicals, metals, plastics, and organic materials all floating in the air, traveling on the winds, until rain brings them back down.  These are the aerosols, and top scientists like James Hansen warns ignoring them is dangerous.

We have new science on aerosol pollution.  The Open Access paper is titled “Rapidly evolving aerosol emissions are a dangerous omission from near-term climate risk assessments”.  Could pollution-driven weather changes be as important for some of you, as greenhouse gas emissions?

The lead author is Dr. Geeta Persad, Assistant Professor of Climate Science at The University of Texas,  Austin.  She leads the Persad Aero-Climate Group there.

Listen to or download this 26 minute interview with Geeta Persad in CD Quality or Lo-Fi


As Persad’s paper points out: “…the impacts of aerosols on climate risk are often ignored. The issue was not on the official agenda of the 27th United Nations climate conference (COP27) in Sharm-El-Shaikh, Egypt.”


There are proposals to cool Earth on an emergency basis by injecting sulfate aerosols into the atmosphere on a continuing basis.  They call it geoengineering.  One of the key objections raised: the possibility of unintended consequences, particularly for the cycle of rain and drought, with things like rainfall in Africa or the Indian Monsoon.  This new research by Persad et al – including the teleconnections map shown in Figure 2 of the new paper – seems to confirm fears of unintended consequences of geoengineering with sulfates.


Revealed: almost everyone in Europe is breathing toxic air
Guardian investigation finds 98% of Europeans breathing highly damaging polluted air linked to 400,000 deaths a year   Wed. Sept 20, 2023


Tens of millions of people have their lives shortened by air pollution.  But does this study imply it is too late to clean up the air?  That we have added so many warming gases that a pollution cleanup might actually cause several times more dead plus mass extinctions?  Maybe we could have ended breathing toxic air in the 1990’s, before we doubled the rate of our emissions, but now we can’t afford it?  Do we need the poisonous air to survive?

Even if clearing up aerosol pollution “only” adds (say) half a degree C. of warming, maybe that could be the extra push that triggers tipping points with unstoppable horrible consequences.  We humans ran a giant experiment with our own air supply and found a climate land mine ready to blow into a hotter world.

Greenhouse gases from burning fossil fuels and agriculture are the prime driver of climate change, but not the only one.  We should not overestimate aerosol changes as THE big factor, but obviously we cannot ignore the impacts of aerosol changes either, and so far, that is what the climate community has done.


David Wallace-Wells (also an Ecoshock guest) writes about this “Faustian bargain” in the New York Times writing:

“…you could see more warming from aerosol drawdowns than from carbon emissions over the next few decades. The pioneering climate scientist James Hansen, who has long called this challenge a “Faustian bargain,” recently suggested that aerosol drawdown may double rates of warming.”

AND JAMES HANSEN’S RECENT BLOG on aerosols and warming (scary stuff).  “Global Warming is Accelerating. Why? Will We Fly Blind?”  14 September 2023

I’ve been covering this for years.  This early Ecoshock piece:  “The Polluted Womb Increase in Asthma, Autism, Learning Disorders”  20 MB 21 min.  Feburary 9, 2006



Dr. Joel Schwartz Harvard Medical Lecture 2006 1 hr long. Important talk for city dwellers. Smog deaths hidden by coroner reports (often heart attack). Best explanation I’ve heard.  Find that Ecoshock piece here.



Let’s keep in this theme with by revisiting my January 2023 interview with another major voice of aerosol risks, Leon Simons.  He publishes with famous climate scientist James Hansen to get air pollution effects into the mainstream climate community, and the public consciousness.

Listen to or download this 26 minute interview with Leon Simons in CD Quality or Lo-Fi


Find all my comments and loads of links on this Simons interview here:

Dark Science: Gone Glaciers and Sudden Warming

You can keep up with Leon’s campaign to make us aware of this little-known warming risk with his “X” (Twitter) feed here.

That replay interview from Radio Ecoshock in January of this year completes our special program on aerosols and climate change.  It is a huge subject.  Breaking science shows even micro-particles of plastic in the air.  Check out my Ecoshock show November 9, 2022 called “Your Body Is Partly Plastic. So Is Everything Else”.  Are you ready for plastic rain?

Your Body Is Partly Plastic. So Is Everything Else

I’m Alex Smith.  Tune in again next week. Thank you for listening, and caring about our world.  Special thanks to the folks who made one-time donations this past week.  You help keep me going!


Dr. Lucky Tran  @luckytran

“A wise person once said that you will experience climate change through a series of increasingly wild videos, until you are the one taking the video.”