Mastodawn

Søren Have Oct 24, 2023

“These results suggest that mitigation of greenhouse gases now has limited power to prevent ocean warming that could lead to the collapse of the West Antarctic Ice Sheet.” 😳

@Ruth_Mottram, did you see this? How to interpret? #dkgreen https://www.nature.com/articles/s41558-023-01818-x

Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century - Nature Climate Change

The authors use a regional ocean model to project ocean-driven ice-shelf melt in the Amundsen Sea. Already committed rapid ocean warming drives increased melt, regardless of emission scenario, suggesting extensive ice loss from West Antarctica.

Nature

Ruth Mottram Oct 24, 2023

@sorenhave well, I'm on my way to a meeting with the authors today, so I'll let you know..
🌞😕

Ruth Mottram Oct 24, 2023

@sorenhave probably worth pointing out that we will have time to move back from the coasts. It is not going to happen overnight, increase in snow fall will help to mitigate the increasing ice loss at least in the first stages.

@Ruth_Mottram I know, and any decimal of a degree still matters. But still 😔.

Ruth Mottram Oct 24, 2023

@sorenhave I do not think that societies in general have realised yet that between 1 and 2m of sea level rise is already inevitable - the question we seek to answer as scientists working on #IceSheets is how fast will we get there?

The answer will vary depending on where you are in the world, but also on how quickly different parts of the cryosphere melt.

I wrote that we should frame it like this for a ministry briefing last year, I don't know if my framing got through though.

Søren Have Oct 24, 2023

@Ruth_Mottram Given the lack of strategic thinking re area use in the ‘plan’ released yesterday, I’m afraid that the message hasn’t really been taken in.

Here’s @CONCITO’s take on it: https://concito.dk/nyheder/ny-klimatilpasningsplan-adresserer-centrale-udfordringer-men-mangler-klare-maal

Ny klimatilpasningsplan adresserer centrale udfordringer, men der mangler klare mål

I dag fik Danmark et udspil til en ny og længe ventet national klimatilpasningsplan. Det er en glædelig nyhed og flere centrale udfordringer adresseres i regeringens udspil. Der er dog fortsat en række væsentlige spørgsmål, der ikke besvares i den fremlagte ”Klimatilpasningsplan 1”.

CONCITO

Ruth Mottram Oct 24, 2023

@sorenhave ah thanks..will take a look later. Maybe you and @CONCITO are interested in a policy briefing we did for the EC that got turned into a publication by the #PROTECT_SLR project. https://protect-slr.eu/2023/08/31/new-publication-adaptation-to-multi-meter-sea-level-rise-should-start-now/

New publication: Adaptation to multi-meter sea-level rise should start now

Søren Have Oct 24, 2023

@Ruth_Mottram @CONCITO Thx! Will send it to my colleagues working on adaptation.

Ruth Mottram Oct 24, 2023

@sorenhave @CONCITO btw, I think what the new paper shows is that maybe the Southern Ocean influence on Antarctica is a true example of a tipping point, where "every decimal point of a degree matters", maybe actually doesn't apply, though it does to many other climate change impacts, simple because the sub-shelf melting of ice is not really linear with temperature but depends on ocean stratification and oscillating from 1 state to another.

Ruth Mottram Oct 24, 2023

@sorenhave @CONCITO I think the framing of "let's see what the next 100 years looks like", which really is an extension of weather forecasting, is provably the wrong way to look at some processes, like ice sheet melt, Amazon dieback and so forth...

Søren Have Oct 24, 2023

@Ruth_Mottram @CONCITO Yes, you need to (try to) model tipping points as the this one you highlighted.

hanscees Oct 25, 2023

@Ruth_Mottram @sorenhave And the ecosysytems collapse is happening right now as well. . My blog describes how SAI can cool the earth in 2 years and keep temperature steady even if CO2 keeps rising.

Please read the blog before you disagree
And sorry, its very long and thorough

#ClimateEmergency #ClimateAction #SAI

https://econrevolt.com/posts/2023/10/stratinj2/

Stratospheric aerosol injection (SAI) can cool the world in two years: we need a treaty to stop climatechange - Economic Capitalism Revolt To Save this Earth

Summer of 2023. Stratospheric aerosol injection treaty needed to stop climatechange impacts

Economic Capitalism Revolt To Save this Earth

Jonathan Schofield Oct 25, 2023

@Ruth_Mottram I live in Portsmouth where they are currently mid-way through spending over £100 million to raise the sea front to protect against sea level rise of *up to* 1m

Ruth Mottram Oct 25, 2023

@urlyman @sorenhave what??!?

Jonathan Schofield Oct 25, 2023

@Ruth_Mottram here’s what we as a city are up to https://southseacoastalscheme.org.uk/

They are explicit about the scale of the sea level threat at 30 seconds in here https://youtu.be/zw0jeDzctZ8?si=KPEzE8dWVXaN0AnW

Southsea Coastal Scheme

Rob Larter Oct 25, 2023

@urlyman @Ruth_Mottram @sorenhave £100M isn't really a lot in terms of what is being considered for other future flood defence schemes. The Environment Agency have estimated that it will cost £16 billion to future proof their "2100 plan" for Thames Estuary defences, which is about 10 times what construction of the Thames Barrier and associated defences originally cost in today's money.

Jonathan Schofield Oct 26, 2023

@PoLaRobs painful though the costs are, I’ve no doubt London will find the money, but… I'm gonna guess that long before London is in danger of being inundated it will have cascading food shortages

Rob Larter Oct 26, 2023

@urlyman Parts of London are in perpetual danger of being inundated. All it would take is one big storm surge coinciding with a lot of water draining from upstream.

Jonathan Schofield Oct 26, 2023

@PoLaRobs fair point. It’s the scale of the inundation and its persistence we’re talking about though. There’s a difference between floods that are devastating in the short term and the tidal baseline being 2 metres higher

Rob Larter Oct 26, 2023

@urlyman It will take far less than a rise of 2 m in tidal baseline to cause immense economic, social and food supply problems worldwide. Look at how much has already had to be spent on flood defences for London, Rotterdam, New Orleans, Venice, etc. etc. and then consider the fact that this was required to cope with a mean sea-level rise over the past century of only around 20 cm.

Rob Larter Oct 26, 2023

@urlyman
Nobody is prepared for the consequences of even a 0.5 m rise this century, which is at the very optimistic end of the spectrum of projections.

Jonathan Schofield Oct 26, 2023

@PoLaRobs I agree. I’m just suggesting that truly tragic outcomes which are not driven by sea level change likely arrive before.

e.g. It’s quite plausible that heat death on the Indian sub-continent accelerates into the millions by the 2030s

Rob Larter Oct 26, 2023

@urlyman The Indian sub-continent is also going to have to deal with serious water supply issues in the not too distant future as Himalayan glaciers recede. It may be true that some other manifestations of warming will cause the biggest problems over the next couple of decades, but in the medium term the consequences of the cryospehere's response are going to be devastating.

Jonathan Schofield Oct 26, 2023

@PoLaRobs no doubt