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
'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
Most climate reporting ignores both our unintentional and intentional capacity of impacting the visible light spectrum of radiation.
November 24, 2025 at 2:25 PM
Most climate reporting ignores both our unintentional and intentional capacity of impacting the visible light spectrum of radiation.
Unfortunately I don't see much evidence of the Paris agreement resulting in significant reduction in GHG emissions.
I have yet to see an attribution study of a relative decrease of CO₂ emissions from SSP5-8.5. E.g. correcting for COVID and the energy wars.
Collision is practically unavoidable:
I have yet to see an attribution study of a relative decrease of CO₂ emissions from SSP5-8.5. E.g. correcting for COVID and the energy wars.
Collision is practically unavoidable:
November 23, 2025 at 10:18 PM
Unfortunately I don't see much evidence of the Paris agreement resulting in significant reduction in GHG emissions.
I have yet to see an attribution study of a relative decrease of CO₂ emissions from SSP5-8.5. E.g. correcting for COVID and the energy wars.
Collision is practically unavoidable:
I have yet to see an attribution study of a relative decrease of CO₂ emissions from SSP5-8.5. E.g. correcting for COVID and the energy wars.
Collision is practically unavoidable:
I dream of a universe wherein the unit of W/m² is common knowledge.
November 23, 2025 at 5:11 PM
I dream of a universe wherein the unit of W/m² is common knowledge.
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)
It doesn't work like that.
Climate sensitivity is higher and aerosols had been hiding more of the GHG warming.
A strong aerosol forcing change from shipping desulphurization is supported by observational evidence:
Climate sensitivity is higher and aerosols had been hiding more of the GHG warming.
A strong aerosol forcing change from shipping desulphurization is supported by observational evidence:
November 22, 2025 at 7:38 PM
It doesn't work like that.
Climate sensitivity is higher and aerosols had been hiding more of the GHG warming.
A strong aerosol forcing change from shipping desulphurization is supported by observational evidence:
Climate sensitivity is higher and aerosols had been hiding more of the GHG warming.
A strong aerosol forcing change from shipping desulphurization is supported by observational evidence:
I expected that these extreme Sea Surface Temperatures would decrease rather than increase the Net-flux anomaly:
November 22, 2025 at 4:37 PM
I expected that these extreme Sea Surface Temperatures would decrease rather than increase the Net-flux anomaly:
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?
You shared it again today and our 2023 study already showed early evidence of a much stronger shipping desulphurization forcing change.
In December 2023 I shared this alternative version of your attribution graph with you:
In December 2023 I shared this alternative version of your attribution graph with you:
November 21, 2025 at 9:46 PM
You shared it again today and our 2023 study already showed early evidence of a much stronger shipping desulphurization forcing change.
In December 2023 I shared this alternative version of your attribution graph with you:
In December 2023 I shared this alternative version of your attribution graph with you:
See the impact of a +0.5 W/m² shipping desulfurization forcing compared to the Forster et al. (=IPCC methodology) here:
November 21, 2025 at 7:37 PM
See the impact of a +0.5 W/m² shipping desulfurization forcing compared to the Forster et al. (=IPCC methodology) here:
@rarohde.bsky.social didn't include it in his attribution figure either.
See study and summary here:
www.tandfonline.com/doi/full/10....
2/
See study and summary here:
www.tandfonline.com/doi/full/10....
2/
November 21, 2025 at 7:37 PM
@rarohde.bsky.social didn't include it in his attribution figure either.
See study and summary here:
www.tandfonline.com/doi/full/10....
2/
See study and summary here:
www.tandfonline.com/doi/full/10....
2/
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/
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.
Should Antarctic Sea Ice be included here?
The Antarctic Ice Sheet has remained remarkably stable, so far.
essd.copernicus.org/articles/15/...
The Antarctic Ice Sheet has remained remarkably stable, so far.
essd.copernicus.org/articles/15/...
November 21, 2025 at 12:28 PM
Should Antarctic Sea Ice be included here?
The Antarctic Ice Sheet has remained remarkably stable, so far.
essd.copernicus.org/articles/15/...
The Antarctic Ice Sheet has remained remarkably stable, so far.
essd.copernicus.org/articles/15/...
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.
November 21, 2025 at 10:14 AM
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.
Role of a strong aerosol forcing in the net forcing increase is even more clear when comparing it to only GHG forcings:
November 20, 2025 at 7:59 AM
Role of a strong aerosol forcing in the net forcing increase is even more clear when comparing it to only GHG forcings:
Sure, but a simple climate model that uses forcings that are not in line with observations will underestimate the rate of warming.
November 20, 2025 at 7:57 AM
Sure, but a simple climate model that uses forcings that are not in line with observations will underestimate the rate of warming.
🌊 🧊 📉
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.
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/
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...