Dr. Crystal A. Kolden
@pyrogeog.bsky.social
Director, UC Merced Fire Resilience Center. Pyrogeographer. I study wildfire in the era of anthropogenic climate change. Former wildland firefighter. Opinions are my own. *she/her* 🔥🔥🔥
Pinned
Welcome friends! For those just joining us, I'm a former USFS firefighter and a pyrogeographer ("studying Fire on Earth"). I direct the Fire Resilience Center at UC Merced where we seek to understand the causes and consequences of wildfire disasters and identify solutions.
Published today: our new paper showing a 44-year trend of increasing global wildfire disasters (fatalities and economic losses) due to climate change-induced extreme weather. www.science.org/doi/10.1126/...
Climate-linked escalation of societally disastrous wildfires
Climate change and land mismanagement are creating increasingly fire-prone built and natural environments. However, despite worsening fire seasons, evidence is lacking globally for trends in socially ...
www.science.org
October 2, 2025 at 6:28 PM
Published today: our new paper showing a 44-year trend of increasing global wildfire disasters (fatalities and economic losses) due to climate change-induced extreme weather. www.science.org/doi/10.1126/...
We have a 5.9kW solar system for 2,700 sq ft house in HOT 🥵 Fresno, CA. We charge a plug-in hybrid daily.
Current house: $24/yr for electricity (PG&E)
Old house (no solar): >$6,000/yr
Our $20K system is paid for in ~3 yrs. Solar is a scientific miracle.
www.motherjones.com/environment/...
Current house: $24/yr for electricity (PG&E)
Old house (no solar): >$6,000/yr
Our $20K system is paid for in ~3 yrs. Solar is a scientific miracle.
www.motherjones.com/environment/...
Trump is trying to kill solar power—here's how to fight back
Rooftop solar is a clean power miracle. Why are we killing it with red tape?
www.motherjones.com
July 29, 2025 at 7:08 PM
We have a 5.9kW solar system for 2,700 sq ft house in HOT 🥵 Fresno, CA. We charge a plug-in hybrid daily.
Current house: $24/yr for electricity (PG&E)
Old house (no solar): >$6,000/yr
Our $20K system is paid for in ~3 yrs. Solar is a scientific miracle.
www.motherjones.com/environment/...
Current house: $24/yr for electricity (PG&E)
Old house (no solar): >$6,000/yr
Our $20K system is paid for in ~3 yrs. Solar is a scientific miracle.
www.motherjones.com/environment/...
It's 2025, and it's still climate change driving major forest loss through wildfires. With insights from @climate-guy.bsky.social and @calxcunningham.bsky.social
@ucmerced.bsky.social @utas.edu.au
www.nytimes.com/2025/07/21/c...
@ucmerced.bsky.social @utas.edu.au
www.nytimes.com/2025/07/21/c...
Climate Change Is Making Fire Weather Worse for World’s Forests
www.nytimes.com
July 25, 2025 at 1:27 AM
It's 2025, and it's still climate change driving major forest loss through wildfires. With insights from @climate-guy.bsky.social and @calxcunningham.bsky.social
@ucmerced.bsky.social @utas.edu.au
www.nytimes.com/2025/07/21/c...
@ucmerced.bsky.social @utas.edu.au
www.nytimes.com/2025/07/21/c...
I've been calling myself a pyrogeographer for over two decades, and now we have a journal just for us, led by the fantastic @mattwjones.bsky.social (full disclosure: I sit on the editorial board). We warmly invite you to submit to #Pyrogeography today!
www.sciencedirect.com/journal/jour...
www.sciencedirect.com/journal/jour...
Journal of Pyrogeography | ScienceDirect.com by Elsevier
Read the latest articles of Journal of Pyrogeography at ScienceDirect.com, Elsevier’s leading platform of peer-reviewed scholarly literature
www.sciencedirect.com
July 21, 2025 at 4:12 PM
I've been calling myself a pyrogeographer for over two decades, and now we have a journal just for us, led by the fantastic @mattwjones.bsky.social (full disclosure: I sit on the editorial board). We warmly invite you to submit to #Pyrogeography today!
www.sciencedirect.com/journal/jour...
www.sciencedirect.com/journal/jour...
Reposted by Dr. Crystal A. Kolden
Happy to share our new paper: we show that human-caused climate change is raising the odds of extreme climate-driven fire years across forested regions of the globe
@climate-guy.bsky.social @pyrogeog.bsky.social
rdcu.be/evJkX
#ClimateChange #Wildfires
@climate-guy.bsky.social @pyrogeog.bsky.social
rdcu.be/evJkX
#ClimateChange #Wildfires
Climate change has increased the odds of extreme regional forest fire years globally
Nature Communications - The authors show that extreme fire years in global forests align with rare fire weather extremes. Climate change has made such extremes 88-152% more probable. These findings...
rdcu.be
July 11, 2025 at 6:57 AM
Happy to share our new paper: we show that human-caused climate change is raising the odds of extreme climate-driven fire years across forested regions of the globe
@climate-guy.bsky.social @pyrogeog.bsky.social
rdcu.be/evJkX
#ClimateChange #Wildfires
@climate-guy.bsky.social @pyrogeog.bsky.social
rdcu.be/evJkX
#ClimateChange #Wildfires
Also, if you're not following @mattwjones.bsky.social please give him a follow.
He's the Editor-In-Chief of the new journal Pyrogeography!
He's the Editor-In-Chief of the new journal Pyrogeography!
More amazing teamwork led by the fantastic @mattwjones.bsky.social to develop a global database of prescribed fire.
New study from my group with stellar international team.
A multi-national dataset of prescribed #fires compiled and standardised from national records, with contemporaneous #weather conditions, land cover, fuel bed type, ++, included with each record.
www.nature.com/articles/s41...
A multi-national dataset of prescribed #fires compiled and standardised from national records, with contemporaneous #weather conditions, land cover, fuel bed type, ++, included with each record.
www.nature.com/articles/s41...
July 3, 2025 at 1:45 PM
Also, if you're not following @mattwjones.bsky.social please give him a follow.
He's the Editor-In-Chief of the new journal Pyrogeography!
He's the Editor-In-Chief of the new journal Pyrogeography!
More amazing teamwork led by the fantastic @mattwjones.bsky.social to develop a global database of prescribed fire.
New study from my group with stellar international team.
A multi-national dataset of prescribed #fires compiled and standardised from national records, with contemporaneous #weather conditions, land cover, fuel bed type, ++, included with each record.
www.nature.com/articles/s41...
A multi-national dataset of prescribed #fires compiled and standardised from national records, with contemporaneous #weather conditions, land cover, fuel bed type, ++, included with each record.
www.nature.com/articles/s41...
A global assemblage of regional prescribed burn records — GlobalRx - Scientific Data
Scientific Data - A global assemblage of regional prescribed burn records — GlobalRx
www.nature.com
July 2, 2025 at 3:16 PM
More amazing teamwork led by the fantastic @mattwjones.bsky.social to develop a global database of prescribed fire.
My theory: some DOGE minion Googled "Hatch Act" and saw the 1939 law preventing political actions by govt employees and said "Let's cut it!"
Not realizing, of course, that the 1887 Hatch Act funds agricultural research at Land Grant schools that directly benefits farmers.🙄
Not realizing, of course, that the 1887 Hatch Act funds agricultural research at Land Grant schools that directly benefits farmers.🙄
They’re trying to quietly eliminate Hatch Act funding for agricultural schools???? @altusda.altgov.info @aaas.org @asa-cssa-sssa.bsky.social
June 6, 2025 at 3:57 PM
My theory: some DOGE minion Googled "Hatch Act" and saw the 1939 law preventing political actions by govt employees and said "Let's cut it!"
Not realizing, of course, that the 1887 Hatch Act funds agricultural research at Land Grant schools that directly benefits farmers.🙄
Not realizing, of course, that the 1887 Hatch Act funds agricultural research at Land Grant schools that directly benefits farmers.🙄
Spent a delightful week in Vienna last month for EGU. What a model for people (not car)-oriented living!
1) Huge car-free areas in the historic city center
2) Amazing public transit system (my 10-yr olds LOVED the subway)
3) Phenomenal bike paths
Rating: 14/10 - I would live there!
#waroncars
1) Huge car-free areas in the historic city center
2) Amazing public transit system (my 10-yr olds LOVED the subway)
3) Phenomenal bike paths
Rating: 14/10 - I would live there!
#waroncars
May 29, 2025 at 7:22 PM
Spent a delightful week in Vienna last month for EGU. What a model for people (not car)-oriented living!
1) Huge car-free areas in the historic city center
2) Amazing public transit system (my 10-yr olds LOVED the subway)
3) Phenomenal bike paths
Rating: 14/10 - I would live there!
#waroncars
1) Huge car-free areas in the historic city center
2) Amazing public transit system (my 10-yr olds LOVED the subway)
3) Phenomenal bike paths
Rating: 14/10 - I would live there!
#waroncars
Reposted by Dr. Crystal A. Kolden
feels like a good day to re-up this reporting. “Every single state in the US where we have vegetation, and particularly where we have vegetation intermixing with communities, we have the potential for extreme fire disasters,” @pyrogeog.bsky.social www.vox.com/climate/2386...
Wildfires are coming... for New Jersey?
Climate change is expanding the list of areas at risk for the worst wildfires.
www.vox.com
April 23, 2025 at 4:25 PM
feels like a good day to re-up this reporting. “Every single state in the US where we have vegetation, and particularly where we have vegetation intermixing with communities, we have the potential for extreme fire disasters,” @pyrogeog.bsky.social www.vox.com/climate/2386...
TOMORROW! There's still time to register:
1pm - Introductions and talk by John Mills of @watchduty.org
2pm - A look ahead at the 2025 Fire Season in CA with @climate-guy.bsky.social
2:15pm - Mitigating smoke with Dr. Sandie Ha
2:30pm - Q&A with all speakers
MEDIA is welcome.
Please join us!
1pm - Introductions and talk by John Mills of @watchduty.org
2pm - A look ahead at the 2025 Fire Season in CA with @climate-guy.bsky.social
2:15pm - Mitigating smoke with Dr. Sandie Ha
2:30pm - Q&A with all speakers
MEDIA is welcome.
Please join us!
On 4/17 @ucmerced.bsky.social Fire Resilience Center will host John Mills, CEO and co-founder of @watchduty.org AND have discussion with @climate-guy.bsky.social and Dr. Sandie Ha on:
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
April 16, 2025 at 9:58 PM
TOMORROW! There's still time to register:
1pm - Introductions and talk by John Mills of @watchduty.org
2pm - A look ahead at the 2025 Fire Season in CA with @climate-guy.bsky.social
2:15pm - Mitigating smoke with Dr. Sandie Ha
2:30pm - Q&A with all speakers
MEDIA is welcome.
Please join us!
1pm - Introductions and talk by John Mills of @watchduty.org
2pm - A look ahead at the 2025 Fire Season in CA with @climate-guy.bsky.social
2:15pm - Mitigating smoke with Dr. Sandie Ha
2:30pm - Q&A with all speakers
MEDIA is welcome.
Please join us!
Climate change continued to have unpredictable impacts on wildfire in 2024. Unexpected shifts, like the Americas producing 40% of C emissions (normally it's <25%), and anomalous events, like the fatal Feb '24 Chile fire or the Pantanal wetlands burning, occur more often.
Kolden et al. document 2024 wildfires, finding:
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
Wildfires in 2024 - Nature Reviews Earth & Environment
Wildfire burned area was 367 Mha in 2024, ranked 17th since 2001. An estimated 1,965 Tg C was released from these fires, 41% of which came from the Americas, far exceeding their usual 25% contribution...
www.nature.com
April 11, 2025 at 7:11 PM
Climate change continued to have unpredictable impacts on wildfire in 2024. Unexpected shifts, like the Americas producing 40% of C emissions (normally it's <25%), and anomalous events, like the fatal Feb '24 Chile fire or the Pantanal wetlands burning, occur more often.
Reposted by Dr. Crystal A. Kolden
Kolden et al. document 2024 wildfires, finding:
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
Wildfires in 2024 - Nature Reviews Earth & Environment
Wildfire burned area was 367 Mha in 2024, ranked 17th since 2001. An estimated 1,965 Tg C was released from these fires, 41% of which came from the Americas, far exceeding their usual 25% contribution...
www.nature.com
April 11, 2025 at 6:36 PM
Kolden et al. document 2024 wildfires, finding:
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
- 367 Mha burned
- Burned area decreased 5.4% from 2023
- Fires released an estimate 1965 Tg C
www.nature.com/articles/s43... (rdcu.be/ehnTP)
@pyrogeog.bsky.social @climate-guy.bsky.social @mattwjones.bsky.social @ueaenv.bsky.social
[6/n]
On 4/17 @ucmerced.bsky.social Fire Resilience Center will host John Mills, CEO and co-founder of @watchduty.org AND have discussion with @climate-guy.bsky.social and Dr. Sandie Ha on:
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
April 9, 2025 at 3:09 PM
On 4/17 @ucmerced.bsky.social Fire Resilience Center will host John Mills, CEO and co-founder of @watchduty.org AND have discussion with @climate-guy.bsky.social and Dr. Sandie Ha on:
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
1) The upcoming fire season in CA
2) How you can prepare, esp. for smoke
We're streaming it online - join us!
This is your regular reminder that ALL buildings in California must build to seismic codes, but only those in CALFIRE's designated high hazard areas must build to WUI fire codes.
Why the discrepancy? Who the hell knows...but it means the cycle of rebuild and burn again will continue.
Why the discrepancy? Who the hell knows...but it means the cycle of rebuild and burn again will continue.
California just released new maps on where homes have to be built with wildfire-resistant materials. But the majority of homes destroyed in the Eaton fire won’t have to use those building codes www.npr.org/2025/03/25/n...
March 27, 2025 at 3:29 PM
This is your regular reminder that ALL buildings in California must build to seismic codes, but only those in CALFIRE's designated high hazard areas must build to WUI fire codes.
Why the discrepancy? Who the hell knows...but it means the cycle of rebuild and burn again will continue.
Why the discrepancy? Who the hell knows...but it means the cycle of rebuild and burn again will continue.
Ed Abbey words to live by:
“A patriot must always be ready to defend his country against his government.”
“Anarchism is founded on the observation that since few men are wise enough to rule themselves, even fewer are wise enough to rule others.”
“Anarchism is democracy taken seriously.”
“A patriot must always be ready to defend his country against his government.”
“Anarchism is founded on the observation that since few men are wise enough to rule themselves, even fewer are wise enough to rule others.”
“Anarchism is democracy taken seriously.”
February 19, 2025 at 10:32 PM
Ed Abbey words to live by:
“A patriot must always be ready to defend his country against his government.”
“Anarchism is founded on the observation that since few men are wise enough to rule themselves, even fewer are wise enough to rule others.”
“Anarchism is democracy taken seriously.”
“A patriot must always be ready to defend his country against his government.”
“Anarchism is founded on the observation that since few men are wise enough to rule themselves, even fewer are wise enough to rule others.”
“Anarchism is democracy taken seriously.”
Worried about wildfires this year? You should be. Preparedness is the absolutely most effective way to mitigate disasters, and the firing of thousands of employees and hiring freeze means that there is almost no one to prepare. WHEN wildfires start (not if), suppression will be a mess.
IMTs are quietly talking about what the current political environment means for this year's wildland fire suppression efforts, but it deserves a larger and more public consideration. 1/
February 19, 2025 at 9:41 PM
Worried about wildfires this year? You should be. Preparedness is the absolutely most effective way to mitigate disasters, and the firing of thousands of employees and hiring freeze means that there is almost no one to prepare. WHEN wildfires start (not if), suppression will be a mess.
"Training is preparation for the known; education is preparation for the unknown."
Just remember that we train AI, but we educate humans.
Just remember that we train AI, but we educate humans.
February 10, 2025 at 4:31 AM
"Training is preparation for the known; education is preparation for the unknown."
Just remember that we train AI, but we educate humans.
Just remember that we train AI, but we educate humans.
Reposted by Dr. Crystal A. Kolden
Out today in @globalchangebio.bsky.social is our (brief!) rapid-response piece on the broader context surrounding the January 2025 Southern California wildfires & relevance of wet-to-dry hydroclimate whiplash to fire both locally and globally on a warming Earth. [1/8] onlinelibrary.wiley....
February 7, 2025 at 11:45 PM
Out today in @globalchangebio.bsky.social is our (brief!) rapid-response piece on the broader context surrounding the January 2025 Southern California wildfires & relevance of wet-to-dry hydroclimate whiplash to fire both locally and globally on a warming Earth. [1/8] onlinelibrary.wiley....
Reposted by Dr. Crystal A. Kolden
Wanted to reshare the webinar event associated with this white paper release.
You can watch the event here: www.youtube.com/watch?v=QkAP...
All of the messages discussed by me and the panelists require greater focus after what we have just experienced.
You can watch the event here: www.youtube.com/watch?v=QkAP...
All of the messages discussed by me and the panelists require greater focus after what we have just experienced.
January 27, 2025 at 6:11 PM
Wanted to reshare the webinar event associated with this white paper release.
You can watch the event here: www.youtube.com/watch?v=QkAP...
All of the messages discussed by me and the panelists require greater focus after what we have just experienced.
You can watch the event here: www.youtube.com/watch?v=QkAP...
All of the messages discussed by me and the panelists require greater focus after what we have just experienced.
🔥 Fire peeps... @wildland-zko.bsky.social joined us. Give him a follow.
@weatherwest.bsky.social I just set up an account here. Can you let your followers know I'm on here, now?
January 26, 2025 at 5:38 PM
🔥 Fire peeps... @wildland-zko.bsky.social joined us. Give him a follow.
I am shocked* that the Trillion Trees guy ends up being a problem dude. They won't comment, but anyone with that kind of funding record doesn't get let go without doing something VERY, VERY BAD.
*Note: I am not shocked at all
*Note: I am not shocked at all
Someone who has brought in tens of millions of dollars and has 40 to 60 people in his group is obviously a big deal at any institution. So, for that institution to let him go says a lot. But another institution is just going to take him in and act like nothing happened?
#AcademicChatter #AcademicSky
#AcademicChatter #AcademicSky
Star ecologist accused of misconduct loses university post
Tree researcher Thomas Crowther is seeking to move his laboratory from ETH Zurich, which says it will not renew his contract.
www.nature.com
January 26, 2025 at 5:35 PM
I am shocked* that the Trillion Trees guy ends up being a problem dude. They won't comment, but anyone with that kind of funding record doesn't get let go without doing something VERY, VERY BAD.
*Note: I am not shocked at all
*Note: I am not shocked at all
Reposted by Dr. Crystal A. Kolden
Access damage info directly from the incident pages:
#PalisadesFire details | www.fire.ca.gov/incidents/20...
#EatonFire details | www.fire.ca.gov/incidents/20...
We’re here to support you on the road to recovery. Stay safe and informed!
#PalisadesFire details | www.fire.ca.gov/incidents/20...
#EatonFire details | www.fire.ca.gov/incidents/20...
We’re here to support you on the road to recovery. Stay safe and informed!
Palisades Fire | CAL FIRE
www.fire.ca.gov
January 17, 2025 at 8:29 PM
Access damage info directly from the incident pages:
#PalisadesFire details | www.fire.ca.gov/incidents/20...
#EatonFire details | www.fire.ca.gov/incidents/20...
We’re here to support you on the road to recovery. Stay safe and informed!
#PalisadesFire details | www.fire.ca.gov/incidents/20...
#EatonFire details | www.fire.ca.gov/incidents/20...
We’re here to support you on the road to recovery. Stay safe and informed!
In Sept 2020, in the wake of a record CA fire season, I wrote an opinion piece for @nature.com about the need to focus on the human metrics of fire, not the acres burned. The #LAFires underscore that our obsession with size fails to convey the scope of the impacts. 🧵
www.nature.com/articles/d41....
www.nature.com/articles/d41....
Wildfires: count lives and homes, not hectares burnt
Smarter ways to assess fires will bring better methods of preventing damage.
www.nature.com
January 16, 2025 at 5:47 PM
In Sept 2020, in the wake of a record CA fire season, I wrote an opinion piece for @nature.com about the need to focus on the human metrics of fire, not the acres burned. The #LAFires underscore that our obsession with size fails to convey the scope of the impacts. 🧵
www.nature.com/articles/d41....
www.nature.com/articles/d41....
An important facet of the fire building code discussion is that it only applies to areas that CALFIRE deems high fire hazard; it's not blanket. Many urban homes burned in recent years were't included. For seismic codes, every house in the state must comply no matter how far from a fault line.
California’s 7A building code is the most robust in the country.
Here’s why that didn’t stop the LA fires, from @zeitlin.bsky.social.
Here’s why that didn’t stop the LA fires, from @zeitlin.bsky.social.
California Has America’s Strictest Wildfire Code
Here’s why it didn’t help Los Angeles.
heatmap.news
January 16, 2025 at 4:12 PM
An important facet of the fire building code discussion is that it only applies to areas that CALFIRE deems high fire hazard; it's not blanket. Many urban homes burned in recent years were't included. For seismic codes, every house in the state must comply no matter how far from a fault line.