Climate Endgame: Exploring catastrophic climate change scenarios

In this Climate Chat episode we discuss the August 2022 paper "Climate Endgame: Exploring catastrophic climate change scenarios" by Luke Kemp, Chi Xu, Joanna Depledge , and Timothy M. Lenton:

The paper explores how the IPCC does not include proper risk assessment of catastrophic climate change scenarios and what proper risk assessment may reveal.

[celestialteapot]

As an elderly poor person who has never flown, owned a car or house l can carry on as l am, as can most of the world.

[martiansoon]

What have you changed? After Californian house was burned for the 3rd time... The people were still building a new one in the same spot...

Or there is an republican run isle on southern coast where some places are already gone under seas with abandon houses. They are still saying its not climate change. We will still vote for worst actors...

Denial is real.

And this is partially why, the hope to get real climate issues done is not likely before it is too late.

3-5C world with mass extinction awaits.

[chris]

The YT channel Cambridge Zero has a discussion on this topic featuring Dr Kemp, Tim Lenton (of tipping points fame) and Godrick Goodwin. A sobering listen

[martiansoon]

Errr... Just mention what happens NOW.

This year:
Mediterranean heatwaves, droughts, forestfires, floods, deaths, ...
Colorado river area drought.
Canadian huge forest fires.
Hawaii town destruction.
Droughts, floods, ... all over the planet. Ie. in China.
Daily cat 5 hurricane...
Bathtub temps on Florida coast.
Heat deaths of many marine species that washed to the shore.
Missing sea ice near Antarctica (size of Argentina) with huge impact on wildlife and total energy imbalance.
Oceans taking Zettajoules of excess energy.
...

Damn.

And those are just extreme events. There are loads more of them and the main underlying trend is getting worse all the time.

Food crisis. Ie. In Greece their one of the main products olive oil, price goed up from 5€ to 20€ in a single year. That tells how bad the situation in our food stability really is.

[willdoe]

I started watching this because I wanted to hear about worst case climate scenarios however that was not what the video was about at all. All I heard was arguments about dumb analogies and opinions so I quit watching.

[martiansoon]

From WMO's current emission plots you may see, that we have been well over the worst case line... In 2019 I estimated that we were roughly 10% above RCP 8.5 emissions...

So this alone should be alarming.

And talks in COP are often made with SSP1 and SSP2 scenarios, that are most likely already GONE.

[martiansoon]

It is insanity to buy a home from Florida.

12-20 meters of sea level rise will flood most of the state under the sea by 2300 @2C warming (State of cryosphere 2023). Accompanied with 10-20 meters of sea level rise with current ghg levels with longer time periods (IPCC).

2C warming is most likely already locked in. (currently @2, 55C when forcings are added, Hansen, 1, 46C +0, 6C = 2, 06C is current temp plus IPCC's aerosol estimate (there are more forcings...))

[basilbrushbooshieboosh]

Took you a while to get Stacey up on screen.

[anngodfrey]

Watch the next posting of Just Have a Think on Sunday at the real state of carbon capture and storage!

[thomasseptimius]

The biggest grifter of them all. Elevating speculative papers as if they are science.

[lyndonbarsten]

Why don't you cut the first 2 minutes 15 seconds?

[reverands]

In looking at SRM, you have to understand that anything that reflects Sunlight during the day, reflects heat back to the surface, at night. It's often greater reflecting heat back down (versus minus 250°C space temperatures), than reflecting Sunlight, during the day.

[martiansoon]

Yea, alveols that plants use as exchanging gases with atmosphere shuts down at around 32C... Over that and plants are just not producing anything and are more or less dying if these temperatures continues over longer timeperiods.

And soil humidity is lost nearly a rate of 7% per 1C. That means lots of drought conditions that are simply killing plants.

And keep in mind, therse are not just 7% here and there, but more likely 50% there and 0% here. The random variability with extreme weather events is extremely harmful.

Having less humidity on ground means more in the atmosphere. This means more severe heavy rains and more floods. Excess humidity is more likely been dropped over one area in shorter time period. This can be seen in many locations already. These heavy rains, or even prolonged rains, means troubles for any harvest.

Jet steams are more likely to lockdown on definate patterns. These are called as Rossby waves. It is more likely to get Rossby 4 in the winter and Rossby 7 in the summer. The number there is amount of the waves. Specially locking down to summertime Rossby 7 may mean there is prolonged droughts in several key food producing areas. That may lead to global famine.

So, there are many threats for our food security. And most of these risks are rising with higher temperatures.

[basilbrushbooshieboosh]

re. to what Stacey R. was saying:

56:58 Clint Eastwood for US President would go a long way towards a proportional response to Climate Change.
And he'd pull in both Rep's. and Dem's.

[anthonymorris]

"Catastrophic climate change scenarios". And people call you alarmists. Go figure.

[basilbrushbooshieboosh]

Ocean fertilisation with iron oxide (iron ore) is by far and away the most effective, efficient and least costly (financially and socially {when targeted appropriately}) method of drawing down atmospheric CO2.
It is a no-brainer but politicians are scared to think of it because they perceive their voters fear it. That may be so, but that is why education of the disastrous risks of Climate Change, and education of the cost/risk analysis of CO2 draw-down MUST be implemented.

[Raze]

51:39 I've run into this problem
1:04:14 ...and this one

[AcheuleanAxe]

Given that CO2 has averaged about 1500 ppm over the last 250 million years and life on earth has thrived, how can we possibly be talking about catastrophic climate change at 420 ppm or even double or triple this?

[shoobidyboop]

IPCC ECS estimate of 2.5-4C with likely 3.1C comes from Sherwood20, which was later reviewed by an actual statistician (Nic Lewis 2022) and found to have errors that, when corrected, show ECS most likely is 2C.

[danielfranklin]

you use the analogy of Russian roulette but you're missing one aspect. There are two Russian roulette sentries one is business as usual climate change and the other is seriously addressing the issue. What are the risks and what humanity look like if we stop climate change. Will there be 8 billion people living a high lifestyle?