Dan Westervelt
@dwesty.bsky.social
Associate professor in climate change, atmospheric chemistry, and air pollution at Columbia-Lamont @lamont.columbia.edu
New wheels! Our first EV, the Kia EV6. Plugged in at the @lamont.columbia.edu charging point conveniently located right outside of my office!
January 21, 2026 at 5:06 PM
New wheels! Our first EV, the Kia EV6. Plugged in at the @lamont.columbia.edu charging point conveniently located right outside of my office!
Textbook winter temperature inversion across the mid-Atlantic today impairing air quality (yellow = moderate AQI). A 20+ ºF swing in warmer temperatures today versus the last few days means warmer air aloft than at the surface (air has a lower heat capacity).
December 18, 2025 at 5:26 PM
Textbook winter temperature inversion across the mid-Atlantic today impairing air quality (yellow = moderate AQI). A 20+ ºF swing in warmer temperatures today versus the last few days means warmer air aloft than at the surface (air has a lower heat capacity).
Reposted by Dan Westervelt
The Trump Administration's plan to dismantle the @ncar-ucar.bsky.social is senseless & dangerous.
It would weaken weather forecasting, climate research, & the science that keeps people safe.
We urge that this plan be abandoned.
Call Congress to #SaveNCAR today. buff.ly/7ka1BQA
It would weaken weather forecasting, climate research, & the science that keeps people safe.
We urge that this plan be abandoned.
Call Congress to #SaveNCAR today. buff.ly/7ka1BQA
Save NCAR from being dismantled today!
The Trump Administration has vowed to dissolve the center that provides critical extreme weather and climate data for our nation.
buff.ly
December 17, 2025 at 7:44 PM
The Trump Administration's plan to dismantle the @ncar-ucar.bsky.social is senseless & dangerous.
It would weaken weather forecasting, climate research, & the science that keeps people safe.
We urge that this plan be abandoned.
Call Congress to #SaveNCAR today. buff.ly/7ka1BQA
It would weaken weather forecasting, climate research, & the science that keeps people safe.
We urge that this plan be abandoned.
Call Congress to #SaveNCAR today. buff.ly/7ka1BQA
There has been a decent amount written thus far on the air pollution response to New York City's congestion pricing policy, most of which has been overwhelmingly positive. While PM2.5 concentrations are indeed down at most locations in NYC, (1/4)
December 15, 2025 at 8:48 PM
There has been a decent amount written thus far on the air pollution response to New York City's congestion pricing policy, most of which has been overwhelmingly positive. While PM2.5 concentrations are indeed down at most locations in NYC, (1/4)
Reposted by Dan Westervelt
In case you're working on NSF COA
Have you tried this one? (Export Author Affiliation; then select Authors all) ui.adsabs.harvard.edu/search/fq=%7...
Astrophysics Data System
A powerful, streamlined new Astrophysics Data System
ui.adsabs.harvard.edu
October 27, 2025 at 12:49 PM
In case you're working on NSF COA
Reposted by Dan Westervelt
Our new article out today takes a hard look at some practical limitations on stratospheric aerosol injection and what they means for the riskiness of this approach. @mcneill-lab.org w/ @gwagner.com & @steingart.bsky.social @climate.columbia.edu @columbiaseas.bsky.social
Here's the press release:
Here's the press release:
How hard is it to dim the Sun?
Solar radiation management is gaining traction as a climate intervention—but new research warns that real-world constraints make it riskier and more uncertain than most models suggest.
www.eurekalert.org
October 21, 2025 at 10:02 AM
Our new article out today takes a hard look at some practical limitations on stratospheric aerosol injection and what they means for the riskiness of this approach. @mcneill-lab.org w/ @gwagner.com & @steingart.bsky.social @climate.columbia.edu @columbiaseas.bsky.social
Here's the press release:
Here's the press release:
Reposted by Dan Westervelt
Columbia Dinner 🩵🩵🩵 with Westervelt Group @dwesty.bsky.social , @mcneill-lab.org past and present, @aqtoolbox.org and some additional @climate.columbia.edu friends! #AAAR2025
October 17, 2025 at 1:18 AM
Columbia Dinner 🩵🩵🩵 with Westervelt Group @dwesty.bsky.social , @mcneill-lab.org past and present, @aqtoolbox.org and some additional @climate.columbia.edu friends! #AAAR2025
Reposted by Dan Westervelt
Nice profile in Columbia News related to the Climate Week event we hosted Monday @aqtoolbox.org @mcneill-lab.org
We sat down with V. Faye McNeill to discuss her work co-leading the Clean Air Toolbox for Cities Initiative. Her upcoming event, happening during #ClimateWeek, will showcase pioneering work by researchers paving the way towards cleaner air and a sustainable climate.
https://bit.ly/46bc2iq
https://bit.ly/46bc2iq
September 26, 2025 at 7:43 PM
Nice profile in Columbia News related to the Climate Week event we hosted Monday @aqtoolbox.org @mcneill-lab.org
Reposted by Dan Westervelt
We sat down with V. Faye McNeill to discuss her work co-leading the Clean Air Toolbox for Cities Initiative. Her upcoming event, happening during #ClimateWeek, will showcase pioneering work by researchers paving the way towards cleaner air and a sustainable climate.
https://bit.ly/46bc2iq
https://bit.ly/46bc2iq
September 19, 2025 at 2:42 PM
We sat down with V. Faye McNeill to discuss her work co-leading the Clean Air Toolbox for Cities Initiative. Her upcoming event, happening during #ClimateWeek, will showcase pioneering work by researchers paving the way towards cleaner air and a sustainable climate.
https://bit.ly/46bc2iq
https://bit.ly/46bc2iq
Reposted by Dan Westervelt
The GRASP dataset is expanding access to air quality data across the continent.
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
September 10, 2025 at 9:35 AM
The GRASP dataset is expanding access to air quality data across the continent.
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
Reposted by Dan Westervelt
📣 A new #AirQuality dataset for Ghana from @dwesty.bsky.social & colleagues
The GRASP dataset is expanding access to air quality data across the continent.
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
Update: Ghana’s dataset is now live, providing daily PM2.5 trends from the early 2000s through 2024. A powerful tool to inform research, policy, and action for #CleanAir4Africa.
🔗 Explore here: bit.ly/42mk99m
September 12, 2025 at 3:47 PM
📣 A new #AirQuality dataset for Ghana from @dwesty.bsky.social & colleagues
Reposted by Dan Westervelt
Register today:
Data and Partnerships for Global Clean Air and Climate
Data and partnerships for global clean air and climate"
www.eventbrite.com
September 5, 2025 at 9:08 PM
Register today:
Reposted by Dan Westervelt
Join us during #ClimateWeek @Columbia for an @aqtoolbox.org event,
"Data and Partnerships for Global Clean Air and Climate"
@columbiaseas.bsky.social @climate.columbia.edu @climategroup.bsky.social @openaq.org @columbiauniversity.bsky.social @lamont.columbia.edu @dwesty.bsky.social
"Data and Partnerships for Global Clean Air and Climate"
@columbiaseas.bsky.social @climate.columbia.edu @climategroup.bsky.social @openaq.org @columbiauniversity.bsky.social @lamont.columbia.edu @dwesty.bsky.social
September 5, 2025 at 9:08 PM
Join us during #ClimateWeek @Columbia for an @aqtoolbox.org event,
"Data and Partnerships for Global Clean Air and Climate"
@columbiaseas.bsky.social @climate.columbia.edu @climategroup.bsky.social @openaq.org @columbiauniversity.bsky.social @lamont.columbia.edu @dwesty.bsky.social
"Data and Partnerships for Global Clean Air and Climate"
@columbiaseas.bsky.social @climate.columbia.edu @climategroup.bsky.social @openaq.org @columbiauniversity.bsky.social @lamont.columbia.edu @dwesty.bsky.social
Reposted by Dan Westervelt
Sometimes patience pays off... This paper has been in the works since I was still in my 30s 🤣
It was a pleasure to travel to Xian and work with @amgcarlton.bsky.social and other friends and colleagues on this
It was a pleasure to travel to Xian and work with @amgcarlton.bsky.social and other friends and colleagues on this
Secondary organic aerosol in urban China: A distinct chemical regime for air pollution studies
In the past decades, China has witnessed high air pollution associated with rapid economic development, although regulatory efforts have alleviated the situation since 2013. Haze events characterized ...
urldefense.proofpoint.com
August 29, 2025 at 2:37 PM
Sometimes patience pays off... This paper has been in the works since I was still in my 30s 🤣
It was a pleasure to travel to Xian and work with @amgcarlton.bsky.social and other friends and colleagues on this
It was a pleasure to travel to Xian and work with @amgcarlton.bsky.social and other friends and colleagues on this
Reposted by Dan Westervelt
Happy to see this one out!
TL;DR: under the right conditions* GUV lamps aren't too bad for air quality in a real-world conference room
*only use the minimum necessary GUV intensity for the space, preferably have good ventilation
journals.plos.org/plosone/arti...
TL;DR: under the right conditions* GUV lamps aren't too bad for air quality in a real-world conference room
*only use the minimum necessary GUV intensity for the space, preferably have good ventilation
journals.plos.org/plosone/arti...
Effects of germicidal far-UVC on ozone and particulate matter in a conference room
The application of 222 nm light from KrCl excimer lamps (GUV222 or far-UVC) is a promising approach to reduce the indoor transmission of airborne pathogens, including the SARS-CoV-2 virus. GUV222 inac...
journals.plos.org
August 11, 2025 at 8:09 PM
Happy to see this one out!
TL;DR: under the right conditions* GUV lamps aren't too bad for air quality in a real-world conference room
*only use the minimum necessary GUV intensity for the space, preferably have good ventilation
journals.plos.org/plosone/arti...
TL;DR: under the right conditions* GUV lamps aren't too bad for air quality in a real-world conference room
*only use the minimum necessary GUV intensity for the space, preferably have good ventilation
journals.plos.org/plosone/arti...
Reposted by Dan Westervelt
In the past, emissions from power plants or vehicles were bigger drivers of bad air quality. Now, wildfires are pretty much the whole story when it comes to air quality problems in the US, says @lamont.columbia.edu climate scientist @dwesty.bsky.social. Via @npr.org.
Canadian wildfires are impacting air quality in the U.S.
Canada is having its second worst wildfire season yet. Two scientists explain what a red air alert means and how anyone living in impacted areas can protect themselves.
www.npr.org
August 8, 2025 at 1:36 PM
In the past, emissions from power plants or vehicles were bigger drivers of bad air quality. Now, wildfires are pretty much the whole story when it comes to air quality problems in the US, says @lamont.columbia.edu climate scientist @dwesty.bsky.social. Via @npr.org.
Reposted by Dan Westervelt
New study finds that cleaner air has accelerated the increase in heatwaves. "The findings are compelling and add to a growing body of literature on how aerosols can have out-sized impacts on climate extremes," says @lamont.columbia.edu climate scientist @dwesty.bsky.social. Via @newscientist.com.
Cleaner air has increased the number of city heatwaves
Reducing air pollution is critical for improving public health, but it has brought big climate trade-offs
www.newscientist.com
July 23, 2025 at 1:00 PM
New study finds that cleaner air has accelerated the increase in heatwaves. "The findings are compelling and add to a growing body of literature on how aerosols can have out-sized impacts on climate extremes," says @lamont.columbia.edu climate scientist @dwesty.bsky.social. Via @newscientist.com.
Nice article on a recent insightful paper, featuring a quote from me
Cleaning up aerosol pollution is critical for public health. But reducing aerosols is also unmasking warming from greenhouse gases - researchers here find this influence is strongest in populated places. 🧪
Cleaner air has increased the number of city heatwaves
Reducing air pollution is critical for improving public health, but it has brought big climate trade-offs
www.newscientist.com
July 22, 2025 at 7:07 PM
Nice article on a recent insightful paper, featuring a quote from me
New research from a large team including myself pointing to aerosol reductions in East Asia being responsible for recent observed acceleration in global warming. In particular we find this to be a bigger driver than the oft-mentioned shipping sulfur emissions reductions.
New study by LDEO's @dwesty.bsky.social, CCSR/NASAGISS' Larissa Narazenko & Kostas Tsigaridis et. al. finds that cleanup of air pollution in East Asia has accelerated global warming because some forms have helped shade the Earth's surface from the sun's energy: lamont.columbia.edu/news/air-pol...
July 16, 2025 at 4:00 PM
New research from a large team including myself pointing to aerosol reductions in East Asia being responsible for recent observed acceleration in global warming. In particular we find this to be a bigger driver than the oft-mentioned shipping sulfur emissions reductions.
Reposted by Dan Westervelt
"If you look at a time series of the entire year of data, you can almost instantly pick out July 4th because there'll be a huge spike in particulate matter concentration," says @lamont.columbia.edu expert @dwesty.bsky.social, with implications for the environment & health. Via The Weather Channel.
How Fireworks Impact The Environment - Videos from The Weather Channel
Fireworks are synonymous with the Fourth of July, but they come with a hidden cost. Beyond the bright colors and loud booms, they release pollution and harmful chemicals that can impact both the envir...
weather.com
July 7, 2025 at 4:38 PM
"If you look at a time series of the entire year of data, you can almost instantly pick out July 4th because there'll be a huge spike in particulate matter concentration," says @lamont.columbia.edu expert @dwesty.bsky.social, with implications for the environment & health. Via The Weather Channel.
Reposted by Dan Westervelt
If they close all these research labs, you can't just undo it four years later.
Decades of expertise and tons of specialized equipment will be scattered to the wind. Rebuilding would take ages.
Decades of expertise and tons of specialized equipment will be scattered to the wind. Rebuilding would take ages.
Proposed NOAA budget zeros out ALL climate laboratories and cooperative institutions.
GFDL, NSSL, GML, etc.
This appears to also end the US greenhouse gas sampling network, including at Mauna Loa, the oldest continuous carbon dioxide monitoring site on Earth.
www.commerce.gov/sites/defaul...
GFDL, NSSL, GML, etc.
This appears to also end the US greenhouse gas sampling network, including at Mauna Loa, the oldest continuous carbon dioxide monitoring site on Earth.
www.commerce.gov/sites/defaul...
July 1, 2025 at 1:13 PM
If they close all these research labs, you can't just undo it four years later.
Decades of expertise and tons of specialized equipment will be scattered to the wind. Rebuilding would take ages.
Decades of expertise and tons of specialized equipment will be scattered to the wind. Rebuilding would take ages.
Reposted by Dan Westervelt
Besides the fact that it's hot AF, our air quality is garbage today. I don't know about you but for my asthma, ozone days like this hit harder than PM days, and the heat is an extra load on your body. Keep cool and take it easy.
June 23, 2025 at 7:49 PM
Besides the fact that it's hot AF, our air quality is garbage today. I don't know about you but for my asthma, ozone days like this hit harder than PM days, and the heat is an extra load on your body. Keep cool and take it easy.
Reposted by Dan Westervelt
The smoke from Canada’s wildfires may be even more toxic than usual.
A legacy of mining means that toxic metals could be carried along plumes of smoke.
grist.org/climate/cana...
#Wildfire #Smoke #Wildfires #Climate #Air #AQI
A legacy of mining means that toxic metals could be carried along plumes of smoke.
grist.org/climate/cana...
#Wildfire #Smoke #Wildfires #Climate #Air #AQI
The smoke from Canada's wildfires may be even more toxic than usual
The country's legacy of mining means that toxic metals could be carried along plumes of smoke, endangering people in its path.
grist.org
June 5, 2025 at 1:45 PM
The smoke from Canada’s wildfires may be even more toxic than usual.
A legacy of mining means that toxic metals could be carried along plumes of smoke.
grist.org/climate/cana...
#Wildfire #Smoke #Wildfires #Climate #Air #AQI
A legacy of mining means that toxic metals could be carried along plumes of smoke.
grist.org/climate/cana...
#Wildfire #Smoke #Wildfires #Climate #Air #AQI
Wildfire smoke is back across most of the eastern half of the US! It was this month 2 years ago that an exceptional smoke event blanketed NYC and much of the east coast, vaulting the story into national news. Here's a spotlight I did back then which is still relevant: www.curbed.com/2023/06/nyc-...
Talking to an Air-Quality Expert About That Haze
Should you go outside? Wear a mask? Let us explain.
www.curbed.com
June 4, 2025 at 3:27 PM
Wildfire smoke is back across most of the eastern half of the US! It was this month 2 years ago that an exceptional smoke event blanketed NYC and much of the east coast, vaulting the story into national news. Here's a spotlight I did back then which is still relevant: www.curbed.com/2023/06/nyc-...