Climate catastrophes continue to mount. New paper “Climate Endgame: Exploring catastrophic climate change scenarios” with Lead author Luke Kemp. Then Greenland ice expert Jason Box warns Earth is already committed to at least another foot of sea level rise, from Greenland alone, no matter what we do.

I’m Alex Smith. Welcome to Radio Ecoshock.

Listen to or download this Radio Ecoshock show in CD Quality or Lo-Fi



Greenhouse gas emissions continue to increase. Climate disasters struck repeatedly this year, with eye-popping heat records across the Northern Hemisphere. Scientists ask: why don’t we study the harsher reality. What happens if planet Earth smashes past the two degrees C, going over 3 degrees by the end of this century? That possibility is growing, but officials and institutions are still in denial.

We have a landmark new paper titled: “Climate Endgame: Exploring catastrophic climate change scenarios”. The Abstract for this paper asks: Could anthropogenic climate change result in worldwide societal collapse or even eventual human extinction? So far, mainstream institutions have avoided asking those questions. Now they must.

The authors include former advisor to Angela Merkl (and the Pope) Joachim Schellnhuber, plus Radio Ecoshock guests Johan Rockstrom from Sweden and the UK’s Timothy Lenton. These are senior serious scientists with a warning: we gravely underestimated climate risks. Now have to consider global warming beyond 3 degrees C.

From the UK, we reached the lead author, Dr. Luke Kemp. With his PhD in International Relations from Australian National University, Luke is a Research Associate at the Cambridge Centre for the Study of Existential Risk.

Listen to or download this half hour interview with Dr. Luke Kemp in CD Quality or Lo-Fi


Each report by the Intergovernmental Panel on Climate Change gets worse, with more frightening predictions. Kemp explains why this group of experts say they have not gone far enough. In 2019, Kemp’s co-author Tim Lenton led a study into “tipping cascades”. But has this possibility been digested into institutional science?

“irreversible transition to Hothouse Earth”

The “Climate Endgame” paper also worries about an “irreversible transition to Hothouse Earth”. Few of us can imagine what is Hothouse Earth is like. And the science of physics and natural systems suggest there is a point where humans could not stop that march to a hotter planet. Unlike many other works, this paper includes an open discussion on the possibility of mass casualties due to climate-driven extremes, including a loss of 10% or even 25% of the current human population

Of course humans will react to continuing climate-driven threats. Maybe we will make it worse. Luke Kemp also published on the possibilities and pitfalls of deploying sulfur particles into the air to create a temporary cooling shade over Earth, or parts of the planet. Stratospheric Aerosol Injection (SAI) is a type of geoengineering called “SRM” for Solar Radiation Management. In our interview, Kemp relays some serious implications and possible downsides to SRM. In my opinion, humans will probably become desperate and willful enough to try almost anything to stop climate catastrophe – probably within a decade?

SEE: A. Tang, L. Kemp, A fate worse than warming? Stratospheric aerosol injection and catastrophic risk. Front. Clim. Sci.3, 1–17 (2021).

This new Climate Endgame paper in the Proceedings of the National Academy describes four reasons we should worry more about climate catastrophe, not just climate change. One is the history of previous transitions back and forth from icehouse Earth to hothouse Earth. Second, they say: “…climate change could directly trigger other catastrophic risks, such as international conflict, or exacerbate infectious disease spread, and spillover risk.

This is a kind of breakthrough in this paper. Previously, scientists tried to provide scenarios based on natural systems, geology and so forth. It was like saying: “Here is the science. How humans react is your problem. That is beyond science.” But when we need to predict complex systems, human actors are obviously major actors in the climate future. For those who want to try long-range plans for governments and corporations, we cannot pretend that humans are not part of equations for possible futures. This team investigates ways to include the interplay of human civilization and natural systems.

Now the world is so-interconnected, financial experts worry about a global financial crash as never before seen. Or maybe a nuclear war erupts. Can we handle those human crisis – even while a climate shift is delivering repeated extreme weather bombs, higher seas, and drought?


From the “Climate Endgame” paper:

“...this is how risk unfolds in the real world. For example, a cyclone destroys electrical infrastructure, leaving a population vulnerable to an ensuing deadly heat wave (4). Recently, we have seen compound hazards emerge between climate change and the COVID-19 pandemic. As the IPCC notes, climate risks are becoming more complex and difficult to manage, and are cascading across regions and sectors.”


From the “Climate Endgame” paper:

“UN Secretary-General António Guterres called climate change an ‘existential threat.’ Academic studies have warned that warming above 5 °C is likely to be ‘beyond catastrophic’ , and above 6 °C constitutes ‘an indisputable global catastrophe’.”


From the “Climate Endgame” paper:

“Why the focus on lower-end warming and simple risk analyses? One reason is the benchmark of the international targets: the Paris Agreement goal of limiting warming to well below 2 °C, with an aspiration of 1.5 °C. Another reason is the culture of climate science to “err on the side of least drama”, to not to be alarmists, which can be compounded by the consensus processes of the IPCC. Complex risk assessments, while more realistic, are also more difficult to do.”

This paper also provides a chart defining terms like “risk cascade”, “Extinction risk”, “Societal collapse” and “Global catastrophic threat”. We are just beginning the language needed just to describe novel risks in a destabilized future.

MIT Professor Daniel Rothman published two key papers on thresholds of catastrophe and extinction. I interviewed him after each one. See my notes and links below for those.

Unrelenting heating, weather disruption, and human conflict – all take place on a planetary platform which repeatedly goes to life-threatening extremes with or without humans. What happens if we add natural shocks, like multiple eruptions of volcanoes, or long-cycle weather variations, to the rough and ready mix we already experienced these past few years? Those big ticket natural events might cool Earth down for a few years (volcanoes) before even more heat emerges from our continuing emissions. Or a true once-in-a-hundred-year super El Nino might push us to a new hot stage within a year.

Those are just some of the reasons we need real emergency action to slash fossil emissions as soon as possible. This is a great must-read Open Access paper in one the top journals, PNAS, the Proceedings of the National Academy of Sciences. In conclusion, this group of noteworthy scientists are calling for “An IPCC Special Report on Catastrophic Climate Change” as a way to kick-start global research into real hazards of rapid climate change.


Because this paper is so important, Canadian climate scientist Paul Beckwith just put up a detailed video explaining it. Start with this YouTube video “Climate Endgame Research Framework”. Paul says this is “crucial information for all humans to understand.



I plan to have Paul on Radio Ecoshock show soon, to talk about a string of powerful science papers in the last three months. Of course this stuff is right down Paul’s alley. He has studied climate extremes for well over a decade. Paul tells me he will travel to Sharm El-Sheikh Egypt for the COP27 climate conference at the end of November. He will do a presentation on this “Climate Endgame” paper. Tune in next week for more.


D. H. Rothman, Thresholds of catastrophe in the Earth system. Sci. Adv. 3, e1700906 (2017).

I covered the 2017 Rothman paper with Daniel Rothman here:

Beyond the Threshold

That show was called “Beyond the Threshold” – posted on November 16, 2017.

…and his 2019 paper here:

The American Carbon Bomb

Show title: “The American Carbon Bomb”, posted on November 27, 2019.

… the brilliant Daniel Rothman from MIT examines past mass extinctions – only to discover a new threshold approaching, hidden deep in the ocean.



New science shows almost a foot of sea level rise is guaranteed from Greenland ice melt alone, no matter what we do next. Ports and food-growing deltas around the world will be invaded by the sea. And that is the minimum – it could be much worse.

The lead author is well-known glaciologist Jason Box. Jason is a hybrid. His earned his PhD in Colorado and works abroad as professor in glaciology at the Geological Survey of Denmark and Greenland. But Jason’s real home may be Greenland. Now, after twelve years of research and two years of peer review, Jason leads a team publishing a landmark paper on expected sea level rise from Greenland melt.

Listen to or download this 28 minute interview with Dr. Jason Box in CD Quality or Lo-Fi


The new paper is titled “Greenland ice sheet climate disequilibrium and committed sea-level rise”. I did not fully understand the concept of equilibrium for an ice sheet, until I watched Jason’s video about this new paper on YouTube.




Calculating the amount of water lost by Greenland is not easy. Some areas may be getting thicker ice, gaining mass, while other are losing. Meanwhile, snow, rain, and run-off keep changing the numbers on the run. All that along with ice lost breaking off into the sea and likely underground/underwater meltwater runoff channels – even the best models could not do it. These scientists found a different approach, avoiding modeling in favor of geophysical data: mass measurements by the Grace satellites, photos from space – a wide variety of means to construct a picture of Greenland losing mass as the great ice sheet begins to melt away.

Using established measurements, they were able to calculate the amount of mass that is already sure to disappear into the ocean. Call it “committed melt” or “zombie ice” – no matter what emissions route humans take, this amount of sea level rise will happen anyway: 274 ± 68 mm [10.7”] higher seas.

While no one can say exactly how long that runoff will take, the consensus is most of it will appear during this century. Vast amounts of sensitive delta farmlands will be first filled with salt, and then flooded altogether. Many world ports and airports may have to be rebuilt, or depend on super expensive dikes against the sea.  That is the minimum. In the paper, the authors explain how they used the very minimal factors to produce their number for ice loss and sea level rise.


The paper outlines three scenarios. The first is the headline: over 10 inches, or 274 millimeters of sea level rise is definitely coming from the warming we stimulated so far. That is pretty certain and Jason explains how we know.  Keep in mind, there is a break-through technique developed in this paper. Instead of depending completely on ice models – the only tool we had to date – this team integrated a massive river of data from satellites all the way to the bottoms of glaciers. The basis is geophysical data – plus a clear model of the shape glaciers will and must take as they encounter warmer conditions. See that in Jason’s video (posted above).

The tools employed – things like measuring changes in gravity from the Grace Satellites, and many other measurements – they can forecast how much melt, but apparently not how fast and when. In the interview, Jason says other experts consider it highly likely most of that ten plus inches of sea level contribution could come during the next 100 years. But that is outside the sights of this current paper, which asks “how much”?


Of course that rate depends on (a) variations in the natural system and (b) changes forced by human emissions of greenhouse gases. In 2012, a staggering amount of ice disappeared from Greenland, changing the mass of the continent. There was a lot of heat. So the second scenario involves a future that assumes Greenland continues with nire conditions like 2012.

If the high-melt year of 2012 is taken as an example of what to expect as warming continues, the committed sea level rise – from Greenland alone – would be just over 30 inches, or roughly 782 millimeters. That could come even if we somehow slash emissions in the next ten years. Disaster at the coasts, and for economies generally, is assured.

Were we to experience a burst of warming, perhaps due to a methane event, or just because we continue to increase pollution – sea level rise would be much higher. It is hard to imagine the consequences.

In 2018, ice loss on Greenland was far less than in 2012, and less than the recent ten year average. This paper examines the amount of sea level rise contributed by Greenland IF Arctic conditions are mostly as they were in 2018. We get less sea level, but so far this reduced melt scenario seems the least likely to me.


Box was early to call out the problem of pollution changing the shade of Greenland from pristine white to dirty gray. That led to the public-funded Dark Snow Project. Is that change of albedo significant for this new assessment of Greenland ice loss? “Yes” says Box, but it turns out even more darkening comes from a different source: algae living in the ice. When conditions are right, plants manage to grow just below the ice surface, sort of protected but still getting some light. Perhaps those conditions are increasing with warming, and this is an unexpected part of glacier decay?

Jason Box also championed a new way of looking at changes in Greenland’s ice. Most of us picture huge icebergs calving off into the sea as the major source of sea level rise. But research by Box and colleagues found the largest source of ice waters from Greenland to the Atlantic is not calving but meltwater. Heating on the surface of the glacier creates streams and then rivers of water. Some of it pours down hole to the base of the ice, reach the ocean deep under the surface.

Some of the temporary lakes and general melt on Greenland just evaporates into the atmosphere. Jason’s PhD concerned ice lost through evaporation. How is most of the ice leaving Greenland: is it flowing out to sea or evaporating into the atmosphere? Is melting Greenland becoming a source of more water vapor, thus adding to global warming, and perhaps more extreme rainfall somewhere else?


Jason has published book and video series called “Faster than Forecast: the story ice tells about abrupt climate change”. When a person buys a chapter of the book, Box promises to plant a tree on Greenland, through the group

Dr. Box’s work is featured in the movie Chasing Ice. Follow Jason Box on Twitter.

If you have a subscription, here is a very good Washington Post article about this new Greenland science – and it’s implications for Antarctic melt.


WHEN THE BRITISH ISLES ICE SHEET MELTED, sea levels rose 120 meters in about 18,000 years.

The general see-saw of ice is a very slow build-up of ice, and slow fall of sea levels, reinforced by intrinsic feedbacks like increase albedo. But once a warming starts, the record shows, sea levels rise much quicker. That is the situation we are in now.

AROUND 8,200 YEARS AGO A MELTWATER PULSE first created a very quick sea level rise between 1 and 3 feet.

However, due to disruption of North Atlantic currents, a colder period lasting between 60 and 150 years followed. This is the 8,.2 ka cooling event.



Just 15,000 years ago! Is this a case study for what to expect in Greenland?

Two more key Greenland papers just came out in September. The first is a huge study of the British Islands Ice Sheet. Massive glaciers covered most of the UK and Ireland until just 15,000 years ago. Ice experts formed a group called BRITICE-CHRONO. They created the best picture we have of mass ice sheet decline – or maybe collapse. The second paper provides unexpected details of HOW the great British glaciers melted. Are there built-in brakes slowing ice sheet decay?

I discussed that with lead author Dr. James D. Kirkham. He is from the British Antarctic Survey and the Department of Geography at the University of Cambridge. Essentially, their team was able to re-use very detailed studies of the bottom of the North Sea, done for oil and gas exploration, and wind towers as well. They found a maze of deep channels, some like little valleys, buried beneath the surface mud. With testing two things became apparent: these channels were created by a torrent of meltwater trying to escape under heavy ice; and these new geographical features were created in a short time, likely a few hundred years.

Check out the British Antarctic Survey press release, “Ice age valleys give clues to future ice sheet change” about this new paper. This paper is titled “Tunnel valley formation beneath deglaciating mid-latitude ice sheets: Observations and modelling”.

As they say: “The work highlights a currently overlooked process that can rapidly switch on beneath melting ice sheets. Whether these channels will act to stabilise or destabilise the Earth’s contemporary ice sheets in a warming world remains an important and open question.”

Will these new studies on the breakup of the British Isles ice sheet help us understand the development and warning signs of Greenland ice melt? Are under-ice valleys already being carved under Greenland right now? Would there be a two hundred year explosion of change as glaciers lose ice faster due to Arctic warming? Now we have more clues to work with, and a beautiful timeline for the disappearance of glaciers from the British Isles, one of the top case studies possible for Greenland’s future.

Anybody who looks at rock formations in Britain, Ireland or Scotland sees tracks of great glaciers. It’s wild to think your “green and pleasant land” looked more like Greenland just a few thousands years ago. But this northern ice sheet extended beyond the shore of the British Isles, right out over the current North Sea to Scandinavia.

SEE ALSO: “Growth and retreat of the last British–Irish Ice Sheet, 31 000 to 15 000 years ago: the BRITICE-CHRONO reconstruction” published 07 September 2022 as Open Access (free to read) article. Study led by Chris D. Clark.


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I’m Alex Smith. Thank you so much for listening, and caring about our world.