Leon Simons
@leonsimons.com
Mission: To understand & protect the home planet. Innovator, climate research & communication, social entrepreneur. Board member Club of Rome NL
How manny will keep denying acceleration of global warming is real if this central estimate of global temperature above pre-industrial materializes in 2027?
Zeke Hausfather@zekehausfather.com · 3d agoI'm not sure folks have realized just how crazy the second half of 2026 and 2027 will be for global temperatures – on the back of a record-smashing El Niño event. Here is my latest estimate of where both years will end up compared to global temperatures since 1850.
Great summary of why "Europe is hot as f*ck" this summer, by comedian Ryan Kelly on Instagram.
Leon Simons@leonsimons.com · 4d agoEurope’s Summer of Reckoning Is ‘Just the Beginning’ “2026 is just the beginning,” Professor Rockström added. “It will inevitably get worse. It will get worse and worse and worse to the point where, I’m afraid, we’ll be passing the limits of adaptation.” @nytimes.com 1/
"The Netherlands can't stop climate change. Let's just embrace living under water." 🤦
Sunday 8/2 at 10am PT on Climate Chat: Just the Beginning: Global Heat & Local Extremes with @leonsimons.com & Dan Miller. @bikingmzstacey.bsky.social @radsci.bsky.social #Heatwave #ClimateCrisis @drjamesehansen.bsky.social youtube.com/live/BJtbaDI...
Just the Beginning: Global Heat & Local Extremes with Leon Simons & Dan Miller
YouTube video by Climate Chat
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Europe’s Summer of Reckoning Is ‘Just the Beginning’ “2026 is just the beginning,” Professor Rockström added. “It will inevitably get worse. It will get worse and worse and worse to the point where, I’m afraid, we’ll be passing the limits of adaptation.” @nytimes.com 1/
2027 is now expected to reach 1.7C in my model – exactly where Hansen predicted it would land (albeit in the GISTEMP dataset) back in December 2025:
US embassies are quite subtle, aren’t they? Could barely tell which country this one represents.
Ik ben er later wel nog uitgebreid met @harmedens.bsky.social over in gesprek gegaan op @bnr.nl duurzaam. youtu.be/kR5v0WgItUc
3°C graden warmer in 2050 is nu een reëel scenario, Leon Simons op BNR
YouTube video by Leon Simons
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En ik schreef dit nieuwsstuk - een verslag van de presentatie van @leonsimons.com met een boodschap die zo heftig is, dat geen van de journalisten het aandurfde hier apart nieuws van te maken - (ik ga hier later nog een keer op in) 3/ reportersonline.nl/over-25-jaar...
Over 25 jaar kan de wereld al tot 3 graden zijn opgewarmd - Reporters Online
Acht deskundigen en wetenschappers trokken deze week aan de noodrem. De aanleiding: in aanloop naar de verkiezingen praten politici en media nauwelijks over het klimaat. En dat terwijl de opwarming vo...
reportersonline.nl
How long CO₂ lasts in the atmosphere largely depends on how much humanity keeps emitting, how much the world warms and how strong carbon-cycle feedbacks are and will be. See IPCC AR6 WG1 feedbacks figure, Ts.17 3/ @ghostpanther.bsky.social
Hoe Nederlandse media berichten over extreem weer
This is such a great visualization of the carbon cycle and of how humanity has completely altered it within a geological instant. Visualization by @rarohde.bsky.social. 1/
Breaking News! Code: y-Axis Alert! / UFB!!! On July 25th, global sea-surface temperatures set a record high anomaly of 0.80°C above the 1991-2020 mean, breaking the previous record of 0.76°C set in January, 2024. I had to extend the y-axis to show yesterday's SST anomaly.
Q: "Are we ready for the age of global wildfires?" A: Not at all!
Climate News@climatenews.bsky.social · 2w agoFrance is on fire. Spain is on fire. Norway is on fire. Sicily is on fire. Ontario is on fire. Scotland is on fire. Bolivia is on fire. Algeria is on fire. England is on fire. Greta wasn't wrong when she said our house was on fire. We are in a climate emergency. - Greenpeace UK
"2026 and 1997 are El Niño twins, both featuring 8°C ocean temperature anomalies beneath the surface of the Pacific. But they're not identical. This year's El Niño is warmer across a wider region, meaning there's more heat in the tank and its impacts won't exactly mirror 1997." Ben Noll
So a lot of this + a record Super El Niño. Hold on to your hats people. And hold your representatives accountable!
Adam McKay@ghostpanther.bsky.social · 2w agoYellowDot released this letter today calling for disaster preparedness for the heat jump this El Niño will bring. It’s signed by scientists, meteorologists, climate writers, concerned citizens & was sent to every Governor, major city Mayor, international Mayors. Sign + share if you can.
YellowDot released this letter today calling for disaster preparedness for the heat jump this El Niño will bring. It’s signed by scientists, meteorologists, climate writers, concerned citizens & was sent to every Governor, major city Mayor, international Mayors. Sign + share if you can.
You can hide it in the very fine print, but the truth is that the warming rate is mainly based on simple models (FaIR). That's not specified in the main paper or in communications (like your CB article today..) This is ridiculous. E.g. assuming biomass aerosols are anthropogenic (but CO₂ isn't):
Most of the science (even coauthored by Mann) agrees that OHC incr & EEI increased. Global temperatures during an El Niño of a certain strength will be higher than would be the case without accelerated warming. Mann his recent paper 'conveniently' doesn't even mention the rate of warming or EEI..
For reference bsky.app/profile/leon...
Leon Simons@leonsimons.com · 3mo agoNew Mann et al. @pnas.org study misrepresents our @drjamesehansen.bsky.social et al. 2023 research. And the source they cite on a low shipping forcing states: "We do not explicitly account for the introduction of strict fuel sulfur controls brought in by the International Maritime Organization"
I would add: 5: How does your model compare to real world observations? Both global and regional models often underestimate crucial real world changes:
A good task of any scientific theory is how well it can predict the future. @leonsimons.com ‘s prediction that increased controls on shipping sulphur aerosol emissions in the Mediterranean (which came into effect May 1 2025) would contribute to increased regional warming seems to have been bang on
Leon Simons@leonsimons.com · last yr.This is no joke! One month from now, sulphur emissions over the Mediterranean will be reduced by another 80%. This will further accelerate regional warming and lead to more extreme droughts, heatwaves, and flash floods.
Please don't downplay the impacts accelerated warming combined with a Super El Niño could have. It could impact real people's lives. The precautionary principle applies and with great reach (e.g. ~100k on Blue Sky and >200k on Twitter/X followers) comes great responsibility.
Leon Simons@leonsimons.com · 3mo agoHe send this to @tenneynaumer.bsky.social (who I've known for almost 20 years and respect very much) when she asked for advice to protect herself against heatwaves:
It looks like extreme summer heatwaves in the Mediterranean are the "new normal". 2 x ~80% desulphurization of shipping definitely (in 2020 maximum sulphur fuel content from 3.5% to 0.5% and in 2025 from 0.5% to 0.1%) contributes to this.
Leon Simons@leonsimons.com · 2y agoSulphur emissions from shipping have kept the oceans and seas relatively cold. On May 1st 2025, 3 months from today, sulphur emissions over the Mediterranean Sea will be reduced by another 80%. How will that impact the regional climate?
New Mann et al. @pnas.org study misrepresents our @drjamesehansen.bsky.social et al. 2023 research. And the source they cite on a low shipping forcing states: "We do not explicitly account for the introduction of strict fuel sulfur controls brought in by the International Maritime Organization"
The "possible good news" at the end will shock you! (Yes, click bait, but please do click)
James Hansen@drjamesehansen.bsky.social · 2w agoThe race is on. The stakes are high. Understanding. Without that, why should anybody listen? See Beware Media Hype – mailchi.mp/caa/beware-m... Also available on Substack: jimehansen.substack.com/p/beware-med...
We haven't seen anything of what climate change will have in store for us the next 20 years! This Super El Niño is only just materializing and will be an indication of what the average year will more or less look like a decade from now. Based on the past years, I think denial will only increase.
Just Some Grey Bunny@greybunny.bsky.social · 2w agoNo shade, but saying we're about to find out while we're currently choking on the smoke of North America burning and heat wave deaths in Europe break 10k is just about the perfect illustration of what a frog-boiling problem climate change messaging is.
