Leon Simons
@leonsimons.bsky.social
Mission: To understand & protect the home planet.
Innovator, climate research & communication, social entrepreneur.
Board member Club of Rome NL
Innovator, climate research & communication, social entrepreneur.
Board member Club of Rome NL
Pinned
Leon Simons
@leonsimons.bsky.social
· Jun 6
No one should be surprised when a planet that accumulates heat more than twice as fast starts to see temperatures go up more than twice as fast.
This isn't rocket science, but we do need more of these NASA satellites. 🌍🛰
To keep us from going blind.
bsky.app/profile/leon...
This isn't rocket science, but we do need more of these NASA satellites. 🌍🛰
To keep us from going blind.
bsky.app/profile/leon...
'The [North-East Atlantic Emission Control Area], which would be the largest of its kind, was approved during the 83th Marine Environment Protection Committee meeting this April and originally due to be adopted [...] for implementation from 2028.'
The climate is at the whim of ignorant plutocrats
The climate is at the whim of ignorant plutocrats
November 24, 2025 at 3:28 PM
'The [North-East Atlantic Emission Control Area], which would be the largest of its kind, was approved during the 83th Marine Environment Protection Committee meeting this April and originally due to be adopted [...] for implementation from 2028.'
The climate is at the whim of ignorant plutocrats
The climate is at the whim of ignorant plutocrats
Reposted by Leon Simons
A second opportunity to examine the cloud reduction effects from shipping fuel pollution measures has revealed that the 80% cut in sulphur emissions reduces cloud droplet formation by 67%.
acp.copernicus.org/articles/25/...
#aerosols #climatechange #clouds #IMO2020 #ECS
acp.copernicus.org/articles/25/...
#aerosols #climatechange #clouds #IMO2020 #ECS
acp.copernicus.org
November 24, 2025 at 11:55 AM
A second opportunity to examine the cloud reduction effects from shipping fuel pollution measures has revealed that the 80% cut in sulphur emissions reduces cloud droplet formation by 67%.
acp.copernicus.org/articles/25/...
#aerosols #climatechange #clouds #IMO2020 #ECS
acp.copernicus.org/articles/25/...
#aerosols #climatechange #clouds #IMO2020 #ECS
Reposted by Leon Simons
Unfortunately, mentioning exclusion rarely gets any response.
@hausfath.bsky.social and @climateofgavin.bsky.social didn't include the Hansen et al. observation based forcing (+0.5 W/m²) and global warming (0.2°C) estimate of shipping aerosols in their WMO report, without argumentation.
1/
@hausfath.bsky.social and @climateofgavin.bsky.social didn't include the Hansen et al. observation based forcing (+0.5 W/m²) and global warming (0.2°C) estimate of shipping aerosols in their WMO report, without argumentation.
1/
November 21, 2025 at 7:37 PM
Unfortunately, mentioning exclusion rarely gets any response.
@hausfath.bsky.social and @climateofgavin.bsky.social didn't include the Hansen et al. observation based forcing (+0.5 W/m²) and global warming (0.2°C) estimate of shipping aerosols in their WMO report, without argumentation.
1/
@hausfath.bsky.social and @climateofgavin.bsky.social didn't include the Hansen et al. observation based forcing (+0.5 W/m²) and global warming (0.2°C) estimate of shipping aerosols in their WMO report, without argumentation.
1/
3 Climate Truths Everyone Must Know
YouTube video by Climate Chat
www.youtube.com
November 23, 2025 at 5:37 PM
Reposted by Leon Simons
Sunday 11/23 at 10am PT on Climate Chat: 3 Climate Truths Everyone Must Know w/ hosts Dan Miller & @leonsimons.bsky.social.
#ClimateCrisis #ClimateAction
@bikingmzstacey.bsky.social @radsci.bsky.social
youtube.com/live/xn4Zr2E...
#ClimateCrisis #ClimateAction
@bikingmzstacey.bsky.social @radsci.bsky.social
youtube.com/live/xn4Zr2E...
3 Climate Truths Everyone Must Know
YouTube video by Climate Chat
youtube.com
November 22, 2025 at 7:58 PM
Sunday 11/23 at 10am PT on Climate Chat: 3 Climate Truths Everyone Must Know w/ hosts Dan Miller & @leonsimons.bsky.social.
#ClimateCrisis #ClimateAction
@bikingmzstacey.bsky.social @radsci.bsky.social
youtube.com/live/xn4Zr2E...
#ClimateCrisis #ClimateAction
@bikingmzstacey.bsky.social @radsci.bsky.social
youtube.com/live/xn4Zr2E...
COP30 President:
"We want to ensure transparency, inclusivity, predictability and legitimacy.
Does everyone agree with this approach?"
Saudi Arabia:
"Hell no, we need you to confirm that our backroom huddle meetings remain, so we can halt progress without anyone noticing"
(Somewhat paraphrasing)
"We want to ensure transparency, inclusivity, predictability and legitimacy.
Does everyone agree with this approach?"
Saudi Arabia:
"Hell no, we need you to confirm that our backroom huddle meetings remain, so we can halt progress without anyone noticing"
(Somewhat paraphrasing)
November 22, 2025 at 7:47 PM
COP30 President:
"We want to ensure transparency, inclusivity, predictability and legitimacy.
Does everyone agree with this approach?"
Saudi Arabia:
"Hell no, we need you to confirm that our backroom huddle meetings remain, so we can halt progress without anyone noticing"
(Somewhat paraphrasing)
"We want to ensure transparency, inclusivity, predictability and legitimacy.
Does everyone agree with this approach?"
Saudi Arabia:
"Hell no, we need you to confirm that our backroom huddle meetings remain, so we can halt progress without anyone noticing"
(Somewhat paraphrasing)
Another month of NASA CERES satellite data and it's only getting worse!
0.11 W/m² added to the 4-year average Net-flux increase over the North Pacific.
Absorbed Solar Radiation is almost 5W/m² higher than at the start of the century.
All added greenhouse gases since 1750 cause a 4.1 W/m² forcing
0.11 W/m² added to the 4-year average Net-flux increase over the North Pacific.
Absorbed Solar Radiation is almost 5W/m² higher than at the start of the century.
All added greenhouse gases since 1750 cause a 4.1 W/m² forcing
November 22, 2025 at 4:08 PM
Another month of NASA CERES satellite data and it's only getting worse!
0.11 W/m² added to the 4-year average Net-flux increase over the North Pacific.
Absorbed Solar Radiation is almost 5W/m² higher than at the start of the century.
All added greenhouse gases since 1750 cause a 4.1 W/m² forcing
0.11 W/m² added to the 4-year average Net-flux increase over the North Pacific.
Absorbed Solar Radiation is almost 5W/m² higher than at the start of the century.
All added greenhouse gases since 1750 cause a 4.1 W/m² forcing
I noticed this in the North West during sunrise and asked my brother with PhD in clouds @yanndu.bsky.social what it was.
Turns out it's very rare phenomena called "anticrepuscular rays" or "God rays" 😍🌤
Turns out it's very rare phenomena called "anticrepuscular rays" or "God rays" 😍🌤
November 22, 2025 at 1:35 PM
I noticed this in the North West during sunrise and asked my brother with PhD in clouds @yanndu.bsky.social what it was.
Turns out it's very rare phenomena called "anticrepuscular rays" or "God rays" 😍🌤
Turns out it's very rare phenomena called "anticrepuscular rays" or "God rays" 😍🌤
My thoughts on COP30?
November 21, 2025 at 10:04 PM
My thoughts on COP30?
These lyrics from the 'Don't look up' documentary on climate change always hit hard:
'Although there are oceans we must cross
And mountains that we must climb
I know every gain must have a loss,
So pray that our loss is nothing but time'
Leonardo DiCaprio recited this at the end.
'Although there are oceans we must cross
And mountains that we must climb
I know every gain must have a loss,
So pray that our loss is nothing but time'
Leonardo DiCaprio recited this at the end.
November 21, 2025 at 5:43 PM
These lyrics from the 'Don't look up' documentary on climate change always hit hard:
'Although there are oceans we must cross
And mountains that we must climb
I know every gain must have a loss,
So pray that our loss is nothing but time'
Leonardo DiCaprio recited this at the end.
'Although there are oceans we must cross
And mountains that we must climb
I know every gain must have a loss,
So pray that our loss is nothing but time'
Leonardo DiCaprio recited this at the end.
Reposted by Leon Simons
Warning! This colorful chart is censored by IPCC - mailchi.mp/caa/warning-...
Also available on Substack: jimehansen.substack.com/p/warning-th...
Also available on Substack: jimehansen.substack.com/p/warning-th...
November 21, 2025 at 3:33 PM
Warning! This colorful chart is censored by IPCC - mailchi.mp/caa/warning-...
Also available on Substack: jimehansen.substack.com/p/warning-th...
Also available on Substack: jimehansen.substack.com/p/warning-th...
Reposted by Leon Simons
Reduced Complexity Model Intercomparison Project Phase 3 preprint: egusphere.copernicus.org/preprints/20...
In parallel to experiments run by complex climate models, we evaluate the simple climate models that are used as translations of knowledge from physical science to scenario projections
In parallel to experiments run by complex climate models, we evaluate the simple climate models that are used as translations of knowledge from physical science to scenario projections
Reduced Complexity Model Intercomparison Project Phase 3: Experimental protocol for coordinated constraining and evaluation of Reduced-Complexity Models
Abstract. Reduced-Complexity Models (RCMs) are a critical tool for synthesising climate science knowledge and providing climate projections for a wide range of emissions scenarios. The Reduced-Complex...
egusphere.copernicus.org
November 21, 2025 at 3:41 PM
Reduced Complexity Model Intercomparison Project Phase 3 preprint: egusphere.copernicus.org/preprints/20...
In parallel to experiments run by complex climate models, we evaluate the simple climate models that are used as translations of knowledge from physical science to scenario projections
In parallel to experiments run by complex climate models, we evaluate the simple climate models that are used as translations of knowledge from physical science to scenario projections
A fire started at the East African Community stand in Belém during #COP30.
Investigations are still ongoing, but I can't help to think of the billion people in Africa still depending on biomass for cooking their food and all the fires and indoor air pollution deaths it causes.
Investigations are still ongoing, but I can't help to think of the billion people in Africa still depending on biomass for cooking their food and all the fires and indoor air pollution deaths it causes.
November 21, 2025 at 11:24 AM
A fire started at the East African Community stand in Belém during #COP30.
Investigations are still ongoing, but I can't help to think of the billion people in Africa still depending on biomass for cooking their food and all the fires and indoor air pollution deaths it causes.
Investigations are still ongoing, but I can't help to think of the billion people in Africa still depending on biomass for cooking their food and all the fires and indoor air pollution deaths it causes.
Great news for ocean altimetry observations! 🌍🛰
Global sea level rise is also a crucial indicator of Earth's Energy Imbalance.
It takes about 50 times as much heat to increase sea levels by thermal expension of the oceans than it does from melting ice.
Satellites paint a very worrying picture!
Global sea level rise is also a crucial indicator of Earth's Energy Imbalance.
It takes about 50 times as much heat to increase sea levels by thermal expension of the oceans than it does from melting ice.
Satellites paint a very worrying picture!
November 20, 2025 at 3:14 PM
Great news for ocean altimetry observations! 🌍🛰
Global sea level rise is also a crucial indicator of Earth's Energy Imbalance.
It takes about 50 times as much heat to increase sea levels by thermal expension of the oceans than it does from melting ice.
Satellites paint a very worrying picture!
Global sea level rise is also a crucial indicator of Earth's Energy Imbalance.
It takes about 50 times as much heat to increase sea levels by thermal expension of the oceans than it does from melting ice.
Satellites paint a very worrying picture!
The ocean has been helping us by withdrawing CO₂ from the atmosphere at an ever increasing rate.
The AMOC plays a crucial role in transporting the carbon to the deep ocean.
Weakening of the AMOC could reduce the ocean CO₂ sink by as much as 100 billion tons this century.
The AMOC plays a crucial role in transporting the carbon to the deep ocean.
Weakening of the AMOC could reduce the ocean CO₂ sink by as much as 100 billion tons this century.
November 20, 2025 at 10:11 AM
The ocean has been helping us by withdrawing CO₂ from the atmosphere at an ever increasing rate.
The AMOC plays a crucial role in transporting the carbon to the deep ocean.
Weakening of the AMOC could reduce the ocean CO₂ sink by as much as 100 billion tons this century.
The AMOC plays a crucial role in transporting the carbon to the deep ocean.
Weakening of the AMOC could reduce the ocean CO₂ sink by as much as 100 billion tons this century.
Reposted by Leon Simons
Updated.
robbieandrew.github.io/GCB2025/
robbieandrew.github.io/GCB2025/
November 20, 2025 at 8:46 AM
Updated.
robbieandrew.github.io/GCB2025/
robbieandrew.github.io/GCB2025/
🌊 🧊 📉
Global Sea Ice Area Maximum never peaked lower than it did this year...
Less sea ice leads to less sunlight reflection back to space, more (high latitude) heat uptake and even faster ice melt.
Global Sea Ice Area Maximum never peaked lower than it did this year...
Less sea ice leads to less sunlight reflection back to space, more (high latitude) heat uptake and even faster ice melt.
November 17, 2025 at 8:08 PM
🌊 🧊 📉
Global Sea Ice Area Maximum never peaked lower than it did this year...
Less sea ice leads to less sunlight reflection back to space, more (high latitude) heat uptake and even faster ice melt.
Global Sea Ice Area Maximum never peaked lower than it did this year...
Less sea ice leads to less sunlight reflection back to space, more (high latitude) heat uptake and even faster ice melt.
Reposted by Leon Simons
Lowest global sea ice maximum area on record. 🧪
November 17, 2025 at 5:56 PM
Lowest global sea ice maximum area on record. 🧪
The scientific understanding is that we should see a decrease in Absorbed Solar Radiation from a negative PDO and a decreasing Net Flux Anomaly as the North Pacific rapidly warms.
The opposite is happening and that's a Big F*cking Deal (BFD) to use @drjamesehansen.bsky.social his phrasing.
1/
The opposite is happening and that's a Big F*cking Deal (BFD) to use @drjamesehansen.bsky.social his phrasing.
1/
November 17, 2025 at 4:02 PM
The scientific understanding is that we should see a decrease in Absorbed Solar Radiation from a negative PDO and a decreasing Net Flux Anomaly as the North Pacific rapidly warms.
The opposite is happening and that's a Big F*cking Deal (BFD) to use @drjamesehansen.bsky.social his phrasing.
1/
The opposite is happening and that's a Big F*cking Deal (BFD) to use @drjamesehansen.bsky.social his phrasing.
1/
Reposted by Leon Simons
Ignoring the tropics because of El Niño/La Niña, the past 12 months show record Sea Surface Temperatures for both hemispheres.
And the acceleration of warming over the Northern Hemisphere is painfully obvious:
And the acceleration of warming over the Northern Hemisphere is painfully obvious:
November 8, 2025 at 11:04 PM
Ignoring the tropics because of El Niño/La Niña, the past 12 months show record Sea Surface Temperatures for both hemispheres.
And the acceleration of warming over the Northern Hemisphere is painfully obvious:
And the acceleration of warming over the Northern Hemisphere is painfully obvious:
Reposted by Leon Simons
From the 2017 Hansen ea paper:
The Framework Convention (UN, 1992) and Paris Agreement (2015) define goals relative to "prein-dustrial" temperature, but do not define that period. We use 1880-1920, the earliest time with near-global coverage of instrumental data'
esd.copernicus.org/articles/8/5...
The Framework Convention (UN, 1992) and Paris Agreement (2015) define goals relative to "prein-dustrial" temperature, but do not define that period. We use 1880-1920, the earliest time with near-global coverage of instrumental data'
esd.copernicus.org/articles/8/5...
November 17, 2025 at 12:24 AM
From the 2017 Hansen ea paper:
The Framework Convention (UN, 1992) and Paris Agreement (2015) define goals relative to "prein-dustrial" temperature, but do not define that period. We use 1880-1920, the earliest time with near-global coverage of instrumental data'
esd.copernicus.org/articles/8/5...
The Framework Convention (UN, 1992) and Paris Agreement (2015) define goals relative to "prein-dustrial" temperature, but do not define that period. We use 1880-1920, the earliest time with near-global coverage of instrumental data'
esd.copernicus.org/articles/8/5...
New record at the main @knmi.nl weather station in De Bilt:
243 days in a row with maximum temperatures above 10°C
www.weeronline.nl/nieuws/15-11...
243 days in a row with maximum temperatures above 10°C
www.weeronline.nl/nieuws/15-11...
November 16, 2025 at 8:41 PM
New record at the main @knmi.nl weather station in De Bilt:
243 days in a row with maximum temperatures above 10°C
www.weeronline.nl/nieuws/15-11...
243 days in a row with maximum temperatures above 10°C
www.weeronline.nl/nieuws/15-11...
November 16, 2025 at 6:03 PM
Great to see NASA GISS back online!
Using a 1880-1920 pre-industrial reference baseline (as preferred by @drjamesehansen.bsky.social et al.), 2025 will be close to +1.5°C.
That's with the tropical Pacific causing some relative cooling (La Niña)!
Using a 1880-1920 pre-industrial reference baseline (as preferred by @drjamesehansen.bsky.social et al.), 2025 will be close to +1.5°C.
That's with the tropical Pacific causing some relative cooling (La Niña)!
November 16, 2025 at 4:25 PM
Great to see NASA GISS back online!
Using a 1880-1920 pre-industrial reference baseline (as preferred by @drjamesehansen.bsky.social et al.), 2025 will be close to +1.5°C.
That's with the tropical Pacific causing some relative cooling (La Niña)!
Using a 1880-1920 pre-industrial reference baseline (as preferred by @drjamesehansen.bsky.social et al.), 2025 will be close to +1.5°C.
That's with the tropical Pacific causing some relative cooling (La Niña)!
Reposted by Leon Simons
And:
"pursuing inadequate methane emission reductions causes remaining carbon budgets compatible with the Paris Agreement temperature limits [plural!] to be exhausted *today* [feb 2024], effectively putting achievement of the Paris Agreement out of reach.'
www.nature.com/articles/s43...
"pursuing inadequate methane emission reductions causes remaining carbon budgets compatible with the Paris Agreement temperature limits [plural!] to be exhausted *today* [feb 2024], effectively putting achievement of the Paris Agreement out of reach.'
www.nature.com/articles/s43...
www.nature.com
November 15, 2025 at 5:48 PM
And:
"pursuing inadequate methane emission reductions causes remaining carbon budgets compatible with the Paris Agreement temperature limits [plural!] to be exhausted *today* [feb 2024], effectively putting achievement of the Paris Agreement out of reach.'
www.nature.com/articles/s43...
"pursuing inadequate methane emission reductions causes remaining carbon budgets compatible with the Paris Agreement temperature limits [plural!] to be exhausted *today* [feb 2024], effectively putting achievement of the Paris Agreement out of reach.'
www.nature.com/articles/s43...