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...
Reposted by Leon Simons
Last year's estimate for 2024 was off by a mile, so I don't put much trust in the 2025 estimate:
November 14, 2025 at 10:54 PM
Last year's estimate for 2024 was off by a mile, so I don't put much trust in the 2025 estimate:
Reposted by Leon Simons
Climate change is accelerating, with the past 10 years the hottest on record. #C3S Director @carlobuontempo.bsky.social calls attention to this rapid evolution, emphasising the importance of scientific data and knowledge to inform action.
⬇️
#CopernicusClimate #COP30
⬇️
#CopernicusClimate #COP30
November 15, 2025 at 10:00 AM
Climate change is accelerating, with the past 10 years the hottest on record. #C3S Director @carlobuontempo.bsky.social calls attention to this rapid evolution, emphasising the importance of scientific data and knowledge to inform action.
⬇️
#CopernicusClimate #COP30
⬇️
#CopernicusClimate #COP30
The RATE of CO₂ increase keeps increasing.
It's not exponential (like the @clubofrome.org 1972 'Limit's to growth' projection), but there is little indication of the growth rate stabilizing (let alone decreasing) any time soon either.
It's not exponential (like the @clubofrome.org 1972 'Limit's to growth' projection), but there is little indication of the growth rate stabilizing (let alone decreasing) any time soon either.
November 15, 2025 at 12:18 PM
The RATE of CO₂ increase keeps increasing.
It's not exponential (like the @clubofrome.org 1972 'Limit's to growth' projection), but there is little indication of the growth rate stabilizing (let alone decreasing) any time soon either.
It's not exponential (like the @clubofrome.org 1972 'Limit's to growth' projection), but there is little indication of the growth rate stabilizing (let alone decreasing) any time soon either.
Reposted by Leon Simons
Greenhouse gases we add to the atmosphere and the resulting Earth's Energy Imbalance could cause about a yottajoule (1,000,000,000,000,000,000,000,000 joules) of heat to accumulate in the Earth system this century.
Causing an energy level similar to the Eemian, when sea level was ~7.5m higher!
1/
Causing an energy level similar to the Eemian, when sea level was ~7.5m higher!
1/
November 14, 2025 at 9:54 PM
Greenhouse gases we add to the atmosphere and the resulting Earth's Energy Imbalance could cause about a yottajoule (1,000,000,000,000,000,000,000,000 joules) of heat to accumulate in the Earth system this century.
Causing an energy level similar to the Eemian, when sea level was ~7.5m higher!
1/
Causing an energy level similar to the Eemian, when sea level was ~7.5m higher!
1/
The atmospheric CO₂ growth rate was off the chart in 2024!
November 14, 2025 at 7:00 PM
The atmospheric CO₂ growth rate was off the chart in 2024!
Journalists around the world keep misrepresenting scientific research on climate change.
Polical reports on false progress don't help.
We could experience monthly temperatures of +2.6°C above pre-industrial during an El Niño in about a decade
And there's a substantial risk of passing +3°C by 2050
Polical reports on false progress don't help.
We could experience monthly temperatures of +2.6°C above pre-industrial during an El Niño in about a decade
And there's a substantial risk of passing +3°C by 2050
November 14, 2025 at 3:42 PM
Journalists around the world keep misrepresenting scientific research on climate change.
Polical reports on false progress don't help.
We could experience monthly temperatures of +2.6°C above pre-industrial during an El Niño in about a decade
And there's a substantial risk of passing +3°C by 2050
Polical reports on false progress don't help.
We could experience monthly temperatures of +2.6°C above pre-industrial during an El Niño in about a decade
And there's a substantial risk of passing +3°C by 2050
Pro-tip for journalists:
Whether it's UNEP, Bill Gates or anyone else making these statements, ask them for their math.
The future non-CO₂ greenhouse gas- and aerosols forcings (that what forces the climate to change) are 'Not Available'...
And climate sensitivity is higher than assumed.
Whether it's UNEP, Bill Gates or anyone else making these statements, ask them for their math.
The future non-CO₂ greenhouse gas- and aerosols forcings (that what forces the climate to change) are 'Not Available'...
And climate sensitivity is higher than assumed.
November 13, 2025 at 2:48 PM
Pro-tip for journalists:
Whether it's UNEP, Bill Gates or anyone else making these statements, ask them for their math.
The future non-CO₂ greenhouse gas- and aerosols forcings (that what forces the climate to change) are 'Not Available'...
And climate sensitivity is higher than assumed.
Whether it's UNEP, Bill Gates or anyone else making these statements, ask them for their math.
The future non-CO₂ greenhouse gas- and aerosols forcings (that what forces the climate to change) are 'Not Available'...
And climate sensitivity is higher than assumed.
Reposted by Leon Simons
Modellen of feitelijke waarnemingen?
"Waar Bill Gates ruimte krijgt zonder goede onderbouwing te roepen dat de opwarming tot 2100 onder de 3°C zal blijven, blijft het onderbelicht dat wij onderbouwen dat dat op basis van waarnemingen al heel onaannemelijk is”
www.h2owaternetwerk.nl/h2o-actueel/...
"Waar Bill Gates ruimte krijgt zonder goede onderbouwing te roepen dat de opwarming tot 2100 onder de 3°C zal blijven, blijft het onderbelicht dat wij onderbouwen dat dat op basis van waarnemingen al heel onaannemelijk is”
www.h2owaternetwerk.nl/h2o-actueel/...
Leon Simons (Club van Rome NL): ‘Houd rekening met 3 graden opwarming rond 2050’
Klimaatmodellen van het Intergovernmental Panel on Climate Change (IPCC) en het KNMI, en daarmee vele klimaatadaptatieplannen die zich hierop baseren, onderschatten sterk hoe snel de aarde opwarmt en ...
www.h2owaternetwerk.nl
November 13, 2025 at 9:21 AM
Modellen of feitelijke waarnemingen?
"Waar Bill Gates ruimte krijgt zonder goede onderbouwing te roepen dat de opwarming tot 2100 onder de 3°C zal blijven, blijft het onderbelicht dat wij onderbouwen dat dat op basis van waarnemingen al heel onaannemelijk is”
www.h2owaternetwerk.nl/h2o-actueel/...
"Waar Bill Gates ruimte krijgt zonder goede onderbouwing te roepen dat de opwarming tot 2100 onder de 3°C zal blijven, blijft het onderbelicht dat wij onderbouwen dat dat op basis van waarnemingen al heel onaannemelijk is”
www.h2owaternetwerk.nl/h2o-actueel/...
Reposted by Leon Simons
Get your fill of Global Carbon Budget 2025 figures and associated data here, released today:
robbieandrew.github.io/GCB2025/
robbieandrew.github.io/GCB2025/
November 13, 2025 at 6:45 AM
Get your fill of Global Carbon Budget 2025 figures and associated data here, released today:
robbieandrew.github.io/GCB2025/
robbieandrew.github.io/GCB2025/
'CERES is the only project worldwide whose prime objective is to produce global climate data records of Earth’s radiation budget (ERB) from instruments designed to observe the ERB'
November 13, 2025 at 1:00 AM
'CERES is the only project worldwide whose prime objective is to produce global climate data records of Earth’s radiation budget (ERB) from instruments designed to observe the ERB'
Reposted by Leon Simons
November 12, 2025 at 8:29 AM
Reposted by Leon Simons
The inadvertent aerosol experiment of shipping desulphurization helps to reduce the largest uncertainty in climate science.
This contributes to the evidence of a much higher climate sensitivity, which means carbon budgets are lower and that we need much faster mitigation
bsky.app/profile/leon...
This contributes to the evidence of a much higher climate sensitivity, which means carbon budgets are lower and that we need much faster mitigation
bsky.app/profile/leon...
If @drjamesehansen.bsky.social at all. (2025, mainly based on NASA CERES observations) is correct about the very strong shipping SOx forcing, the climate is more sensitive to anthropogenic forcings (incl both GHGs and aerosols).
Which e.g. means we need much faster mitigation and adaptation.
Which e.g. means we need much faster mitigation and adaptation.
November 10, 2025 at 3:21 PM
The inadvertent aerosol experiment of shipping desulphurization helps to reduce the largest uncertainty in climate science.
This contributes to the evidence of a much higher climate sensitivity, which means carbon budgets are lower and that we need much faster mitigation
bsky.app/profile/leon...
This contributes to the evidence of a much higher climate sensitivity, which means carbon budgets are lower and that we need much faster mitigation
bsky.app/profile/leon...
Morgen avond vertel ik hoe het er voor staat met het klimaat, in mijn vertrouwde Boxtel.
Op zn Brabants.
Het is gratis, wees welkom (wel even aanmelden, details in dit artikel)
www.brabantscentrum.nl/boxtel/boxte...
Op zn Brabants.
Het is gratis, wees welkom (wel even aanmelden, details in dit artikel)
www.brabantscentrum.nl/boxtel/boxte...
Leon Simons vertelt hoe het ervoor staat met het klimaat
Klimaatwetenschapper Leon Simons, die in Boxtel bij de vroegere boekhandel Elckerlyc heeft gewerkt, geeft woensdag 12 november vanaf 20.00 uur een lezing in de bibliotheek aan de Burgakker 4. Hij vert...
www.brabantscentrum.nl
November 11, 2025 at 3:42 PM
Morgen avond vertel ik hoe het er voor staat met het klimaat, in mijn vertrouwde Boxtel.
Op zn Brabants.
Het is gratis, wees welkom (wel even aanmelden, details in dit artikel)
www.brabantscentrum.nl/boxtel/boxte...
Op zn Brabants.
Het is gratis, wees welkom (wel even aanmelden, details in dit artikel)
www.brabantscentrum.nl/boxtel/boxte...
The past 3-years were on average +1.5°C, while the Relative Oceanic Niño Index was on average -0.19.
The Paris agreement is dead and buried.
What impact will this have on the negotiations in Belém at COP30?
The Paris agreement is dead and buried.
What impact will this have on the negotiations in Belém at COP30?
November 11, 2025 at 12:08 AM
The past 3-years were on average +1.5°C, while the Relative Oceanic Niño Index was on average -0.19.
The Paris agreement is dead and buried.
What impact will this have on the negotiations in Belém at COP30?
The Paris agreement is dead and buried.
What impact will this have on the negotiations in Belém at COP30?
Reposted by Leon Simons
Breaking News!
Code UFB!!!
The three-year running mean for the global surface temperature anomaly now exceeds 1.50°C over the pre-industrial baseline, as of November 8, 2025.
Are you there, COP 30? It's me, the Paris Agreement.
Code UFB!!!
The three-year running mean for the global surface temperature anomaly now exceeds 1.50°C over the pre-industrial baseline, as of November 8, 2025.
Are you there, COP 30? It's me, the Paris Agreement.
November 10, 2025 at 5:02 PM
Breaking News!
Code UFB!!!
The three-year running mean for the global surface temperature anomaly now exceeds 1.50°C over the pre-industrial baseline, as of November 8, 2025.
Are you there, COP 30? It's me, the Paris Agreement.
Code UFB!!!
The three-year running mean for the global surface temperature anomaly now exceeds 1.50°C over the pre-industrial baseline, as of November 8, 2025.
Are you there, COP 30? It's me, the Paris Agreement.
Reposted by Leon Simons
Well a) don't denigrate it as a factoid; it is well established (see eg acp.copernicus.org/articles/24/...)
b) appreciate that in general albedo change is currently accelerating warming, and that regardless of any specific policy responses this is something people need to understand
b) appreciate that in general albedo change is currently accelerating warming, and that regardless of any specific policy responses this is something people need to understand
Warming effects of reduced sulfur emissions from shipping
Abstract. The regulation introduced in 2020 that limits the sulfur content in shipping fuel has reduced sulfur emissions over global open oceans by about 80 %. This is expected to have reduced aerosol...
acp.copernicus.org
November 10, 2025 at 10:19 AM
Well a) don't denigrate it as a factoid; it is well established (see eg acp.copernicus.org/articles/24/...)
b) appreciate that in general albedo change is currently accelerating warming, and that regardless of any specific policy responses this is something people need to understand
b) appreciate that in general albedo change is currently accelerating warming, and that regardless of any specific policy responses this is something people need to understand
Many use the word exponential without knowing what it actually means.
One thing that does increase exponentially is the amount of water the air can hold with every degree Celsius (+7%) of temperature increase.
This leads to both more (extreme) evaporation and precipitation.
One thing that does increase exponentially is the amount of water the air can hold with every degree Celsius (+7%) of temperature increase.
This leads to both more (extreme) evaporation and precipitation.
November 10, 2025 at 2:07 AM
Many use the word exponential without knowing what it actually means.
One thing that does increase exponentially is the amount of water the air can hold with every degree Celsius (+7%) of temperature increase.
This leads to both more (extreme) evaporation and precipitation.
One thing that does increase exponentially is the amount of water the air can hold with every degree Celsius (+7%) of temperature increase.
This leads to both more (extreme) evaporation and precipitation.
Reposted by Leon Simons
Starting soon! Sunday 11/9 at 10am on Climate Chat "What Politics Can & Can't Do for climate" with @jigarshahdc.bsky.social. We'll cover a wide range of topics from new energy to why governments find it hard to act on climate.
@leonsimons.bsky.social @bikingmzstacey.bsky.social @radsci.bsky.social
@leonsimons.bsky.social @bikingmzstacey.bsky.social @radsci.bsky.social
Sunday 11/9 at 10am on Climate Chat "What Politics Can & Can't Do for climate" with @jigarshahdc.bsky.social. We will cover a wide range of topics from new energy sources to why administrations find it so hard to act on climate.
#ClimateCrisis #ClimatePolitics
youtube.com/live/P7W2aAN...
#ClimateCrisis #ClimatePolitics
youtube.com/live/P7W2aAN...
What Politics Can & Can't Do for Climate with Jigar Shah
YouTube video by Climate Chat
youtube.com
November 9, 2025 at 5:39 PM
Starting soon! Sunday 11/9 at 10am on Climate Chat "What Politics Can & Can't Do for climate" with @jigarshahdc.bsky.social. We'll cover a wide range of topics from new energy to why governments find it hard to act on climate.
@leonsimons.bsky.social @bikingmzstacey.bsky.social @radsci.bsky.social
@leonsimons.bsky.social @bikingmzstacey.bsky.social @radsci.bsky.social
Reposted by Leon Simons
Woensdag 12 November vertel ik hoe het er voor staat met het klimaat, in mijn vertrouwde Boxtel.
Op zn Brabants.
Het is gratis, wees welkom.
www.brabantscentrum.nl/boxtel/boxte...
Op zn Brabants.
Het is gratis, wees welkom.
www.brabantscentrum.nl/boxtel/boxte...
Leon Simons vertelt hoe het ervoor staat met het klimaat
Klimaatwetenschapper Leon Simons, die in Boxtel bij de vroegere boekhandel Elckerlyc heeft gewerkt, geeft woensdag 12 november vanaf 20.00 uur een lezing in de bibliotheek aan de Burgakker 4. Hij vert...
www.brabantscentrum.nl
November 5, 2025 at 1:11 PM
Woensdag 12 November vertel ik hoe het er voor staat met het klimaat, in mijn vertrouwde Boxtel.
Op zn Brabants.
Het is gratis, wees welkom.
www.brabantscentrum.nl/boxtel/boxte...
Op zn Brabants.
Het is gratis, wees welkom.
www.brabantscentrum.nl/boxtel/boxte...
😔
"even the lower end of the predicted range for 2025 would result in a 3-year average above 1.5°C, according to the ERA5 dataset. This would be the first time that this has occurred in the instrumental period."
@ecmwf.int
@copernicusecmwf.bsky.social
"even the lower end of the predicted range for 2025 would result in a 3-year average above 1.5°C, according to the ERA5 dataset. This would be the first time that this has occurred in the instrumental period."
@ecmwf.int
@copernicusecmwf.bsky.social
November 8, 2025 at 11:41 PM
😔
"even the lower end of the predicted range for 2025 would result in a 3-year average above 1.5°C, according to the ERA5 dataset. This would be the first time that this has occurred in the instrumental period."
@ecmwf.int
@copernicusecmwf.bsky.social
"even the lower end of the predicted range for 2025 would result in a 3-year average above 1.5°C, according to the ERA5 dataset. This would be the first time that this has occurred in the instrumental period."
@ecmwf.int
@copernicusecmwf.bsky.social
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
Superzellen nehmen zu, das sind die gefährlichsten Gewitter in Europa! Bei 3 Grad zur vorindustriellen Zeit um 50%...Details. #globaleeErhitzung
November 8, 2025 at 9:16 AM
Superzellen nehmen zu, das sind die gefährlichsten Gewitter in Europa! Bei 3 Grad zur vorindustriellen Zeit um 50%...Details. #globaleeErhitzung
'Man who jumped out of an airplane without parachute and who has already hit the ground will overshoot goal not to die, UN said'
November 8, 2025 at 3:56 PM
'Man who jumped out of an airplane without parachute and who has already hit the ground will overshoot goal not to die, UN said'
If our years ran from November to October, 2025 would be the second warmest year on record.
Probably in >100,000 years and potentially much longer.
Sea Surface Temperatures are now likely already higher than during the Eemian warm period, when global sea levels were ~7.5m higher!
Probably in >100,000 years and potentially much longer.
Sea Surface Temperatures are now likely already higher than during the Eemian warm period, when global sea levels were ~7.5m higher!
November 8, 2025 at 3:34 PM
If our years ran from November to October, 2025 would be the second warmest year on record.
Probably in >100,000 years and potentially much longer.
Sea Surface Temperatures are now likely already higher than during the Eemian warm period, when global sea levels were ~7.5m higher!
Probably in >100,000 years and potentially much longer.
Sea Surface Temperatures are now likely already higher than during the Eemian warm period, when global sea levels were ~7.5m higher!