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Messages - Wherestheice

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1
Consequences / Re: World of 2100
« on: June 09, 2020, 01:48:04 AM »
Time frames are interesting.

The world of 2030. That is doable and extrapolation from today is very possible for that.

2100 is interesting too because it is the usual time frame. If you read the replies a lot are rather abstract. And we get to abstract numbers. Billions dead. Could be. We don´t know and we will never see because we will be dead then.

Meanwhile already people are suffering from global warming and this will only get worse.
Because we did not do enough future generations will have to invest into carbon capture. Building more dams or moving whole cities because of sea level rise etc. 

I wonder how they will explain it to the kids. In fact i am wondering how i would explain in 8 to 10 years or so. I don´t have kids myself but my best friend has them. We discussed a newspaper headline related to global warming when they were small (only one head peaking over the table).

Immediately they asked what that was and he explained it in a general way and they went to play but they grow and grow and learn to read and they will ask: Why?

Which is a bloody good question.

The 3k thread got responses that were even more general then here so it was all mere conjecture.

This subforum is for actual consequences. 2030 and 2100 are good timeframes for a more general discussion but focusing on carbon scenarios is probably more constructive then guestimating billions of death.

With all due respect Kassy, I may not be dead in 2100. By that time I will be 99 years old. Unlikely given everything I know, but maybe I will be around somewhere

2
Consequences / Re: World of 2030
« on: June 09, 2020, 01:46:27 AM »
Simple question: In what year will human population peak? Right now human births outnumber deaths by ~80 million people a year. When do folks think annual human deaths will outnumber births?

I'll throw out 2034.  I recognize that represents a dramatic, unprecedented demographic shift.

Nothing unprecedented, but it will be after 2100.

https://population.un.org/wpp/Graphs/DemographicProfiles/Line/900

If the human population doesn't peak till after 2100, good lord I will have to pray for every living species on the planet. If we allow that to happen, there won't be much left.

This is why I think we will peak much sooner. The famous study "Limits to growth", is the key to this topic.

3
Consequences / Re: World of 2100
« on: June 04, 2020, 08:10:20 PM »
Reluctant to post here I do I agree with Wherestheice.

If civilisation collapses around 2030 the GMSTemperatureA may go as high as +4. If it goes on then +6 or higher is on the board. We're talking about a hyperthermal.

Human population will be < 1 billion imo but because of the rising temperature extremes and extremely degrading biosphere, our population will very likely be 0. I think almost all large mammals will be extinct. I think the oceans and climates will have changed considerably. We're witnessing extremely fast anthropogenic mass extinction; what human global civilisation accomplishes is more than 'just' a great extinction event. Never before has GHG risen so fast. Never before have extinctions happened so fast. Never before so much pollution (radioactivity, plastic, forever-chemicals biocides, drugs, nutrients overavailability, genetic modifications, 'breeding', habitat destruction).
    Total destruction.
Do aging Boomers like postulating end dates of 2030 because their own mortality is drawing near? As human generations have become increasingly self-aware and narcissistic it seems that an attraction to postulating the end of the world alongside one's own fate has grown in much of the West. Perhaps it is easier to take solace in one's own looming mortality when one can also imagine looming death for everyone else.

I could see this death drive ultimately doing the species in. One of the presidents of the current cohort pressing the red button in nihilistic spitefulness. Or maybe we will have to wait til 2070 for that to happen. LOL.  :P

Wait there is a second bbr now?

4
Consequences / Re: World of 2100
« on: June 04, 2020, 10:27:54 AM »

Impossible to know with the emergence of AI and Quantum computing...
But China will be on top I guess.

Technological singularity 2029
Full singularity 2045

https://futurism.com/kurzweil-claims-that-the-singularity-will-happen-by-2045
Let's hope those computers can figure out how to save the climate. Because people suck at it...

The computers will solve it.... kill the humans

5
Consequences / Re: World of 2100
« on: June 04, 2020, 10:26:57 AM »
By 2100, I expect the human population to be below 1 billion. At least 4 C warmer, maybe as high as 6.


6
3.25-.75

I sense a big melt, however I am not ready to say if we will get a record low. I think we will get to a 2nd lowest though

7
Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 31, 2020, 07:32:15 AM »
I've always looked at the volume data. That is a good indicator of what the trends in the health of the ice are.

8
Consequences / Re: Places becoming less livable
« on: May 27, 2020, 03:09:44 AM »
Subsidised idiots and communists, without them this planet would be in a much better condition.

Replace communist with capitalist and I agree with you

9
Arctic sea ice / Re: DMI Volume
« on: May 02, 2020, 04:07:23 AM »
I contacted an expert from PIOMAS in regards to the differences between DMI and PIOMAS. Here is what he had to say

"There are some factors behind the different results. The key factors are that these two models differ in model physics, parameterization, resolution, and forcing. The different results are generally caused by these model differences. You can consider this as model uncertainty. Hope this answer your question.
Thanks for the interest and best wishes"

Jinlun Zhang

10
Arctic sea ice / Re: The 2020 melting season
« on: May 01, 2020, 05:39:53 AM »
If you look at the DMI and PIOMAS graphs for volume side by side, you'll notice that the PIOMAS graph shows volume dipping lower than DMI. I to am wondering why this is

11
Consequences / Re: Global Surface Air Temperatures
« on: April 27, 2020, 11:46:17 PM »
March 2020 surface air temperature anomaly seems to have been 1.18C.  Only behind 2016.

https://data.giss.nasa.gov/gistemp/maps/index_v4.html

Using the 1890-1910 baseline, the March anomaly is 1.51 C

12
I fear the COVID situation will precipitate a BOE or near-BOE this summer as we deal with the ramifications of a 30% drop in industrial output, or whatever it is, and ensuing fall in particulates / SO2.

I suspect Hudson Bay will be a lone redoubt for the sea ice, even if it still melts entirely, which is no guarantee. This upcoming winter, I anticipate a very lackluster refreeze, but a very severe winter across North America in particular, with a situation worse than this spring (or 2018) unfolding in 2021. I could see Eurasia being dominated by warmth and having another very early spring / summer next year, just like this one, while the remnants of the PV plop into Hudson Bay and stay there into May, June, and July.

I wonder how long the SWE will persist this yr, as well.

COVID19  or no COVID19, you always think this is the year of an BOE. Considering we have not even seen an ice free north pole, I think an BOE this year is probably less than a 1% probability(always bear in mind nothing is impossible).

Regarding the snow cover situation. Quite an odd situation has occurred, is the significant gains on the Asian snow cover an error or genuine? I think a colder plunge has headed that way whilst a warm plunge has headed towards the Arctic but it does look quite odd imo.

I feel like its more like 10% chance of a BOE occuring at any given year now. In 5 years it will probably be 50% in any given year. In 10 years, somewhere in the 90% margin

13
Policy and solutions / Re: Renewable Energy
« on: April 22, 2020, 08:52:39 PM »
Happy earth day everyone.

https://www.realclearpolitics.com/video/2020/04/21/michael_moore_presents_planet_of_the_humans_documentary_we_are_losing_the_battle_to_stop_climate_change.html

I will watch this after morning chores. I think it is intended to ruffle some feathers...it is Micheal Moore and he wanted it released on Earth Day.
I just started it and I had a hard time hitting stop play. How are they going to know it’s their time to go?

I thought it was overall a good documentary. It showed that renewable energy is a myth, and is just another way for the rich to get richer while destroying the living planet

14
Permafrost / Re: Arctic Methane Release
« on: April 21, 2020, 12:42:03 AM »
I think this could be a more serious problem for the Arctic Ocean, no?
Quote
The depletion of oxygen in the water column could create or expand oxygen minimum zones in the ocean, which are a threat for fishes and other sensitive organisms.
Have there been studies on this? Could increased methane release create dead zones in the Arctic ocean?

https://phys.org/news/2010-12-undersea-methane-contributor-ocean-acidity.html

15
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 15, 2020, 09:04:25 AM »
I guess apocoalypticists are constantly seeing signs of imminent collapse. And have been since at least Ramses' time. I on the other hand, who am absolutely certain that our human civilisation will survive both Covid-19 and AGW, see amazing resilience and innovative adaptation everywhere.

It's clear we disagree here, but that is okay :)

I simply don't see civilization surviving the possible 4-6 C rise this century, I do think human societies can be rebuilt though in certain regions.

Well, lots of things have the capacity to totally wreck human civilisation. But I do not think it is remotely likely that it will happen this century, or that it will happen because of AGW. A rise of 4-6 degrees is not going to happen.

But a lot of people seem to have an apocalyptic deathwish on behalf of their fellow humans. Myself I find it a loathsome attitude.

Nobody can predict the future, but to say a rise of 4-6 C is not going to happen...... all I can say is the science disagrees. It is most certainly in the realm of possiblity, unless some unforseen circumstance appears.

16
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 15, 2020, 08:03:44 AM »
I guess apocoalypticists are constantly seeing signs of imminent collapse. And have been since at least Ramses' time. I on the other hand, who am absolutely certain that our human civilisation will survive both Covid-19 and AGW, see amazing resilience and innovative adaptation everywhere.

It's clear we disagree here, but that is okay :)

I simply don't see civilization surviving the possible 4-6 C rise this century, I do think human societies can be rebuilt though in certain regions.

17
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 15, 2020, 04:29:46 AM »
What the current pandemic has shown, is the entire system is very fragile

If by "system" you mean our human civilisation, then I would disagree. For me it is has been a very big surprise to see how resilient the "system" is to these extreme circumstances.

The only reason it appears resilient, is because everything is shut down. Once this all blows over, there will be a lot of wounds. Just another step towards the eventual collapse. This is just my opinion though.

18
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 15, 2020, 03:48:55 AM »
I suppose i'll add my two bits.

I think its good to have something to stick to, to define what a BOE is. I.e. the 1 million threshold. It obviously doesn't really mean a whole lot, however, it gives us something to refer too. I have come to the conclusion that whether or not the ice melts below that number between now and 2050 probably won't change the outcome for our civilization. What the current pandemic has shown, is the entire system is very fragile. We aren't even in the summer yet for the northern hem. once the chaotic weather comes, we are in for a true wake up.

The more the ice melts, the more screwed we are in the near term. All we can do is follow the data. I do think there is a good chance we go below 1 mil. km2 this decade though, just based off the volume data

WTI

19
The forum / Re: Who would like to take over the ASIF?
« on: April 10, 2020, 06:00:52 AM »
I am not sure how many people moderate now, or if it is just Neven.

My pitch is we elect a a group of moderators. 3-4 individuals or so. Each moderator would have his/her own task, and this would lighten the load on everyone.

This life is short, and with climate change and environmental collapse it always has the potential of being shorter. I do think you should take a break Neven if it is bugging you. We have built a strong community on this forum, and I think we can all be thankful for that.

20
Arctic sea ice / Re: The 2020 melting season
« on: April 08, 2020, 04:32:23 AM »
We won’t likely have a BOE this year but what is the chance of us beating the 2012 record in 2020?

I feel like after every year that passes, the chances of us passing 2012 goes up quite a bit. 2020 could easily be the year

21
The people of this country are gonna have to rise up here pretty soon if we want to have any meaningful future.....

22
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: March 26, 2020, 05:14:28 AM »
Wow things have really accelerated here recently. Considering the winter maximum was so much higher than recent years, this must mean that it was only very weak ice, and now we are seeing the correction to truly reflect the state of the ice?

23
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: March 08, 2020, 05:27:16 AM »
One more day and I think we should start the melting season thread

24
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: March 07, 2020, 08:55:10 AM »
A couple more days of drops like this and i'm calling maximum

25
Consequences / Re: Global Dimming - The aerosol masking effect
« on: February 29, 2020, 05:30:13 AM »
Well there have been multiple studies that show a 35% reduction in industrial activity could lead to a 1 C temperature rise. Guy and Sam both conclude that we are about 1.7 C above the 1750 baseline. But even if we are only 1.2 C warmer, the loss of aerosols is something to be concerned about

26
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: February 07, 2020, 05:23:14 AM »
This winter looks like it will be a winter that stands out in the general trend. What do you think is the reason for this? It looks like there is some extreme cold over the bering sea rn

27
Science / Re: The Science of Aerosols
« on: January 15, 2020, 06:29:36 AM »
Thanks Wherestheice.
-

Are airborne microplastics considered as aerosols?

The billions of rolling car tyres around the world keep on shedding them (emitting) for the foreseeable future.

Seems like they could be, see here... https://earther.gizmodo.com/microplastics-are-airborne-polluted-arctic-snow-reveal-1837239022

"There’s even a chance that the microplastic bits could end up acting like other tiny particles known as aerosols. "

28
But lets be clear that LTG didn't forsee a collapse happening until as late as 2070. So the idea that they predicted collapse in recent decades is false (if that is what you were trying to point out).
Yeah. This propaganda meanwhile has a beard twice as long as Darwin's.

What are you calling propaganda?

29
The most famous is the Club of Rome's Limits to Growth , 1972. It has many iterations ever since. They basically predicted a huge slide of civilization in the 2010-30 period (industrial production collapse, food scarcity, etc). there have been many like this .

And obviously the first one was Malthus, who wrote his works in the early 1800s. His disciples updated it and always expected a collapse in the near future

And I would argue civilization is definitely sliding as we speak. But lets be clear that LTG didn't forsee a collapse happening until as late as 2070. So the idea that they predicted collapse in recent decades is false (if that is what you were trying to point out).

As for Malthus, I don't know anything about his predictions, but it sounds like he had the general idea that to many people will be a problem, and I agree. But that was hundreds of years ago. The world is facing a collapse, and we have data to prove it this time. It is not a question of if, but when.


30
Science / Re: The Science of Aerosols
« on: January 15, 2020, 01:09:50 AM »
Also this.... "the climate and extreme event responses to a removal of anthropogenic aerosols, from a world with around 1.5°C GHG‐dominated warming. Global surface temperature is predicted to increase by 0.7°C (multimodel mean, model range is 0.5–1.1°C), while the land surface warms by 1.0°C (model range 0.7–1.6). As sulfate is the dominant aerosol surface temperature driver for present‐day emissions"

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL076079

31
Science / Re: The Science of Aerosols
« on: January 15, 2020, 01:05:57 AM »
Maybe this paper can help straighten things out a bit?

Their conclusion is that a 35-80% reduction in human emissions would cause a 1 C rise in temp.

And it looks like they don't include BB in their calculations.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrd.50192


32
Science / Re: The Science of Aerosols
« on: January 14, 2020, 07:03:59 AM »
James Hansen gives the number of  0.75 ± 0.25°C per W/m2.

So the -0.9 W/m2 number from AR5 would give ~0.68 degrees C of warming masked by aerosols.

Using the -1.45 W/m2 number from the new paper linked above we get ~1.1 degrees C.

Either way you've got to believe we're well over 1.5C of warming already (plus additional warming from last 10 years of emissions). I'd say (and no one has shown how to get another answer from the math) realistically we're approaching ~2.5C of warming locked in. That means we're desperately scrambling (or we should be) to avoid hitting 3C based on our emissions over the next 2 decades.

Source with Hansen's number:
http://www.columbia.edu/~jeh1/mailings/2018/20181206_Nutshell.pdf

Ah okay, I see. Thank you for explaining. Yeah I don't see us staying below 2 C at this point.The new target needs to be avoiding 3 C.

In that paper that you linked that had the -1.45 W/m2 figure, do we know how much the natural aerosols are blocking? Vs how much the human related aerosols are blocking? I think the latter part of that question is the most important part of this whole discussion.

33
Science / Re: The Science of Aerosols
« on: January 14, 2020, 06:12:19 AM »
Can someone explain to me what -0.9 W/m^2 means in regards to temperature?

34
Nanning,
People have been predicting some sort of global collapse for decades now.  Nothing close has ever materialized.  Some individual countries have gone sour, but even the worst years have not come close.  I seriously doubt we will see any sort of collapse in the near future.

Can you provide one credible example of an expert predicting that civilization was supposed to collapse in recent decades? Because I can't think of any. However, many experts are now saying collapse is possible, if not likely on our current course.

35
Science / Re: 2019 Mauna Loa CO2 levels
« on: December 01, 2019, 07:43:08 AM »
...
The climate will need just a moment to respond to this massive and shockingly sudden insult before it stabilizes. Before that can fully happen we must first stop emitting warming gases.

We are at the beginning of a highly unstable ultra-rapid human caused climatic shift.

...
Sam
Those statements by Sam I bolded are not vindicated by physical facts. There is little cause for such alarmism.

Quite to the contrary. The CO2 in the atmosphere, along with several other key warming gases will take millennia to reduce to prior levels assuming current ecosystem functions. And that only happens if the climate doesn’t shift before that can occur. As the climate shifts, the ecosystems shift, and those basic functions are put at risk.

What should be amply clear (and is) even to young people, let alone to those of us with more life history behind us, is that we are already seeing an ultra rapid shift in progress.

We see that with the rapidly vanishing arctic ice. We see it with the methane boiling out of the clathrates on the arctic plains. We see it with the collapse of the tundra globally. We see it with the warming of the ocean surfaces sufficient to doom coral reefs within the next decade or two. We see it in the hyper rapid acidification of the oceans which doom most shelled creatures. We see it in the very rapid melt on both Greenland and the West Antarctic sheet. We see it in the rapid loss of mountain glaciers and ice all over the world, and with the quite soon loss of the glacial ice supporting a billion people in South Asia. We see it in the destabilization of the atmospheric circulation with massive swings in heat transport both north and south from and to the arctic resulting in climatic chaos in the northern hemisphere beginning. We see it in droughts, fires, deluges and worse. .... and in a thousand other ways ....

Hefaistos, that you apparently choose not see these and myriad indicators is only evidence of your own willful and reckless blindness.

Greta Thunberg is still a young person. Yet she sees clearly, where you do not. She sees the indicators and clearly and concisely called out the leaders of the world in Davos. She is right. You are wrong.

Yes the oceans will take time to equilibrate. And perhaps if we bend every effort, destroying civilization as we know it in the process, we might now barely be able to salvage something of the world we know. Personally, I doubt that is possible any longer. We waited too long. We were too slow to learn. We were and remain too blind to see. And the CO2 trends from Mauna Loa speak volumes to that at megaphone levels. We are not in any way doing what must be done. Instead we argue about slowing the rate of increase of the rate of increase. That is insane.

Worse leaders of major countries are already throwing out efforts to reduce emissions and are instead increasing the rate of burning of oil, coal and natural gas, while also slash burning the lungs of the world. That is beyond insane.

The CO2 already in the atmosphere is catastrophically high. Under the most optimistic business near usual trends, we don’t even slow the increase, let alone stop it, and reverse it. Under these conditions, we will release the 1,600 Gigatons of carbon in the permafrost. And we will boil out the clathrate on the arctic plains, both in the very near future. Either of those take the situation completely out of human control.

Yes the oceans will take time to equilibrate. The continued heat input caused by the warming gases will assure that there is heat enough and time enough to do that. But that is meaningless in the time scale of the catastrophe we face. The continued heating of the Earth from the gases in the atmosphere will assure it. And the changes in the surface biosphere and atmosphere will not wait for that equilibration to finish.

Our rate of change now makes the PETM look obscenely slow. And yet the PETM is the definition of rapid climate change. We are now in the early stages of an ultra rapid climate shift. And that is obvious for all to see except for the willfully blind.

In time, the Earth may shift back to this mostly precariously stable point between hot house and ice house conditions. These have been rare in Earth’s history. The orbital balances could bring us back to some stable place with ice remaining in the Antarctic. And perhaps in half a million years there may be ice in the arctic again. But it is also possible that we continue on a runaway to hot house conditions, having pushed over the climate and ruined the world we know.

I worry more about the highly unstable transition. Creatures can adapt to hundred millennia scale changes. Decade scale changes are another matter entirely. Worse, the impacts of the collapse of whole ecosystems may have dramatically more important transient impacts on O2, pressure, temperature, rainfall, circulation, CO2, methane and other parameters that may drive many species and even whole genera extinct.

Sam

I agree with you Sam, the world is in extremly dire straights now. Anyone who says otherwise isn't paying attention

36
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: November 06, 2019, 12:36:25 AM »
Very nice Gerontocrat.  The open water graphs look more like a phase change occurred around 2007 that anything else.  The volume shows a smoother change.  Either way, the indcation is that a BOE is not imminent, and may not occur at all.

Bruh......Do you need a pair of glasses? Because I think your not understanding this stuff

The percent open water has not increased in over a decade.  Do you see the purple trend line in the volume graph?  Neither graph is popinting towards a BOE anytime soon.  Perhaps you need to borrow my glasses to see them more clearly.

See a trend??

37
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: November 06, 2019, 12:34:00 AM »
Very nice Gerontocrat.  The open water graphs look more like a phase change occurred around 2007 that anything else.  The volume shows a smoother change.  Either way, the indcation is that a BOE is not imminent, and may not occur at all.

Bruh......Do you need a pair of glasses? Because I think your not understanding this stuff

The percent open water has not increased in over a decade.  Do you see the purple trend line in the volume graph?  Neither graph is popinting towards a BOE anytime soon.  Perhaps you need to borrow my glasses to see them more clearly.

I’m not gonna debate with someone who has poor logic and thinking skills. Don’t @ me

38
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: November 05, 2019, 08:11:36 PM »
Very nice Gerontocrat.  The open water graphs look more like a phase change occurred around 2007 that anything else.  The volume shows a smoother change.  Either way, the indcation is that a BOE is not imminent, and may not occur at all.

Bruh......Do you need a pair of glasses? Because I think your not understanding this stuff

39
Permafrost / Re: Permafrost general science thread
« on: October 22, 2019, 06:43:02 AM »
More evidence that the permafrost deniers are wrong.

40
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 11, 2019, 09:48:56 PM »
     FWIW, the September 2019 IPCC cryosphere report shows Extent becoming asymptotic at about 10% of the 2000 level around 2070. 
https://report.ipcc.ch/srocc/pdf/SROCC_FinalDraft_FullReport.pdf
     
     Given the length and detail of the IPCC cryosphere report, there is a surprisingly brief discussion of Arctic sea ice trends.  ASIF is a better source than IPCC! (seriously). After a quick search, I found nothing in the IPCC report about ASI volume projections.  Figure 3.3 on page 3-13 is the closest information.  It charts ASI Extent under the RCP scenarios.  In those projections, even the RCP8.5 scenario retains 10% September Extent for 2070-2100. 

      The scientists who donate their hard work to IPCC reports are the experts and I feel like an ungrateful flea telling the dog what to do in critiquing their work.  But my small fevered brain is unable to reconcile the trends charted by Wipneus and Stephan, or that I can see for myself in the data from PIOMAS, with the IPCC statements shown below from page 3-25.  To be blunt, I suspect that the IPCC is under-estimating the severity of the ASI trends.

Same conclusions (on bold, made by me), long time ago. The IPCC is in fact, avoiding the discussion of when the Arctic will be ice free. It is easier to simulate that they are doing their work, at the same time that they respect politicians.

On the other hand, some of them are politicians!
 ---> IPCC: Intergovernmental Panel of Climate Change.

Edit:
Quote
Greta Thunberg speech at UN Climate Change COP24 Conference:

We have not come here to beg world leaders to care. You have ignored us in the past and you will ignore us again.
We have run out of excuses and we are running out of time.
We have come here to let you know that change is coming, whether you like it or not. The real power belongs to the people.
"...we are running out of time" but the IPCC is still talking about 2100.
"...The real power belongs to the people." ---> ASIF?  ;)

Each of the IPCC reports issued this decade has made projections of when the Arctic will be ice free.

AR5 (2013) Chapter 11, page 995
http://www.climatechange2013.org/images/report/WG1AR5_Chapter11_FINAL.pdf

Quote
Though most of the CMIP5 models project a nearly ice-free Arctic (sea ice extent less than 1 × 106 km2 for at least 5 consecutive years) at the end of summer by 2100 in the RCP8.5 scenario (see Section 12.4.6.1), some show large changes in the near term as well. Some previous models project an ice-free summer period in the Arctic Ocean by 2040 (Holland et al., 2006), and even as early as the late 2030s using a criterion of 80% sea ice area loss (e.g., Zhang, 2010). By scaling six CMIP3 models to recent observed September sea ice changes, a nearly ice-free Arctic in September is projected to occur by 2037, reaching the first quartile of the distribution for timing of September sea ice loss by 2028 (Wang and Overland, 2009). However, a number of models that have fairly thick Arctic sea ice produce a slower near-term decrease in sea ice extent compared to observations (Stroeve et al., 2007). Based on a linear extrapolation into the future of the recent sea ice volume trend from a hindcast simulation conducted with a regional model of the Arctic sea ice–ocean system (Maslowski et al., 2012) projected that
it would take only until about 2016 to reach a nearly ice-free Arctic Ocean in summer. However, such an approach not only neglects the effect of year-to-year or longer-term variability (Overland and Wang, 2013) but also ignores the negative feedbacks that can occur when the sea ice cover becomes thin (Notz, 2009). Mahlstein and Knutti (2012) estimated the annual mean global surface warming threshold for nearly ice-free Arctic conditions in September to be ~2°C above the present derived from both CMIP3 models and observations.
An analysis of CMIP3 model simulations indicates that for near-term predictions the dominant factor for decreasing sea ice is increased ice melt, and reductions in ice growth play a secondary role (Holland et al., 2010). Arctic sea ice has larger volume loss when there is thicker ice initially across the CMIP3 models, with a projected accumulated mass loss of about 0.5 m by 2020, and roughly 1.0 m by 2050, with considerable model spread (Holland et al., 2010). The CMIP3 models tended to under-estimate the observed rapid decline of summer Arctic sea ice during the satellite era, but these recent trends are more accurately simulated in the CMIP5 models (see Section 12.4.6.1). For CMIP3 models, results indicate that the changes in Arctic sea ice mass budget over the 21st century are related to the late 20th century mean sea ice thickness distribution (Holland et al., 2010), average sea ice thickness (Bitz, 2008; Hodson et al., 2012), fraction of thin ice cover (Boe et al., 2009) and oceanic heat transport to the Arctic (Mahlstein et al., 2011). Acceleration of sea ice drift observed over the last three decades, underestimated in CMIP3 projections (Rampal et al., 2011), and the presence of fossil-fuel and biofuel soot in the Arctic environment (Jacobson, 2010), could also contribute to ice-free late summer conditions over the Arctic in the near term. Details on the transition to an ice-free summer over the Arctic are presented in Chapter 12 (Sections 12.4.6.1 and 12.5.5.7).

Special Report Global Warming of 1.5C (2018) Chapter 3, Page 205

https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf

Quote
3.3.8 Sea Ice
Summer sea ice in the Arctic has been retreating rapidly in recent decades. During the period 1997 to 2014, for example, the monthly mean sea ice extent during September (summer) decreased on average by 130,000 km² per year (Serreze and Stroeve, 2015). This is about four times as fast as the September sea ice loss during the period 1979 to 1996. Sea ice thickness has also decreased substantially, with an estimated decrease in ice thickness of more than 50% in the central Arctic (Lindsay and Schweiger, 2015). Sea ice coverage and thickness also decrease in CMIP5 simulations of the recent past, and are projected to decrease in the future (Collins et al., 2013). However, the modelled sea ice loss in most CMIP5 models is much smaller than observed losses. Compared to observations, the simulations are less sensitive to both global mean temperature rise (Rosenblum and
Eisenman, 2017) and anthropogenic CO2 emissions (Notz and Stroeve, 2016). This mismatch between the observed and modelled sensitivity of Arctic sea ice implies that the multi-model-mean responses of future sea ice evolution probably underestimates the sea ice loss for a given amount of global warming. To address this issue, studies estimating the future evolution of Arctic sea ice tend to bias correct the model simulations based on the observed evolution of Arctic sea ice in response to global warming. Based on such bias correction, pre-AR5 and post-AR5 studies generally agree that for 1.5°C of global warming relative to pre-industrial levels, the Arctic Ocean will maintain a sea ice cover throughout summer in most years (Collins et al., 2013; Notz and Stroeve, 2016; Screen and Williamson, 2017; Jahn, 2018; Niederdrenk and Notz, 2018; Sigmond et al., 2018). For 2°C of global warming, chances of a sea ice-free Arctic during summer are substantially higher (Screen and Williamson, 2017; Jahn, 2018; Niederdrenk and Notz, 2018; Screen et al., 2018; Sigmond et al., 2018). Model simulations suggest that there will be at least one sea ice-free Arctic5 summer after approximately 10 years of stabilized warming at 2°C, as compared to one sea ice-free summer after 100 years of stabilized warming at 1.5°C above pre-industrial temperatures (Jahn, 2018; Screen et al., 2018; Sigmond et al., 2018). For a specific given year under stabilized warming of 2°C, studies based on large ensembles of simulations with a single model estimate the likelihood of ice-free conditions as 35% without a bias correction of the underlying model (Sanderson et al., 2017; Jahn, 2018); as between 10% and >99% depending on the observational record used to correct the sensitivity of sea ice decline to global warming in the underlying model (Niederdrenk and Notz, 2018); and as 19% based on a procedure to correct for biases in the climatological sea ice coverage in the underlying model (Sigmond et al., 2018). The uncertainty of the first year of the occurrence of an icefree Arctic Ocean arising from internal variability is estimated to be about 20 years (Notz, 2015; Jahn et al., 2016).
The more recent estimates of the warming necessary to produce an icefree Arctic Ocean during summer are lower than the ones given in AR5 (about 2.6°C–3.1°C of global warming relative to pre-industrial levels or 1.6°C–2.1°C relative to present-day conditions), which were similar to the estimate of 3°C of global warming relative to pre-industrial levels (or 2°C relative to present-day conditions) by Mahlstein and Knutti (2012) based on bias-corrected CMIP3 models. Rosenblum and Eisenman (2016) explained why the sensitivity estimated by Mahlstein and Knutti (2012) might be too low, estimating instead that September sea ice in the Arctic would disappear at 2°C of global warming relative to pre-industrial levels (or about 1°C relative to present-day conditions), in line with the other recent estimates. Notz and Stroeve (2016) used the observed correlation between September sea ice extent and cumulative CO2 emissions to estimate that the Arctic Ocean would become nearly free of sea ice during September with a further 1000 Gt of emissions, which also implies a sea ice loss at about 2°C of global warming. Some of the uncertainty in these numbers stems from the possible impact of aerosols (Gagne et al., 2017) and of volcanic forcing (Rosenblum and Eisenman, 2016). During winter, little Arctic sea ice is projected to be lost for either 1.5°C or 2°C of global warming (Niederdrenk and Notz, 2018).
5

Special Report on Oceans and Crysphere (2019) Chapter 3, Page 3-25

https://report.ipcc.ch/srocc/pdf/SROCC_FinalDraft_Chapter3.pdf

Quote
3.2.2 Projected Changes in Sea Ice and Ocean
 
3.2.2.1 Sea Ice
 
The multi-model ensemble of historical simulations from CMIP5 models identify declines in total Arctic sea ice extent and thickness (Sections 3.2.1.1.1; 3.2.1.1.2; Figure 3.3) which agree with observations (Massonnet et al., 2012; Stroeve et al., 2012a; Stroeve et al., 2014a; Stroeve and Notz, 2015). There is a range in the ability of individual models to simulate observed sea ice thickness spatial patterns and sea ice drift rates (Jahn et al., 2012; Stroeve et al., 2014a; Tandon et al., 2018). Reductions in Arctic sea ice extent scale linearly with both global temperatures and cumulative CO2 emissions in simulations and observations (Notz and Stroeve, 2016), although aerosols influenced historical sea ice trends (Gagné et al., 2017). The uncertainty in sea ice sensitivity (ice extent loss per unit of warming) is quite large (Niederdrenk and Notz, 2018) and the model sensitivity is too low in most CMIP5 models (Rosenblum and Eisenman, 2017). Emerging evidence suggests, however, that internal variability, including links between the Arctic and lower latitude, strongly influences the ability of models to simulate observed reductions in Arctic sea ice extent (Swart et al., 2015b; Ding et al., 2018).
 
CMIP5 models project continued declines in Arctic sea ice through the end of the century (Figure 3.3) (Notz and Stroeve, 2016) (high confidence). There is a large spread in the timing of when the Arctic may become ice free in the summer, and for how long during the season (Massonnet et al., 2012; Stroeve et al., 2012a; Overland and Wang, 2013) as a result of natural climate variability (Notz, 2015; Swart et al., 2015b; Screen and Deser, 2019), scenario uncertainty (Stroeve et al., 2012a; Liu et al., 2013), and model uncertainties related to sea ice dynamics (Rampal et al., 2011; Tandon et al., 2018) and thermodynamics (Massonnet et al., 2018). Internal climate variability results in an uncertainty of approximately 20 years in the timing of seasonally ice-free conditions (Notz, 2015; Jahn, 2018), but the clear link between summer sea ice extent and cumulative CO2 emissions provide a basis for when consistent ice-free conditions may be expected. For stabilized global warming of 1.5°C, sea ice in September is likely to be present at end of century with an approximately 1% chance of individual ice-free years (Notz and Stroeve, 2016; Sanderson et al., 2017; Jahn, 2018; Sigmond et al., 2018); after 10 years of stabilized warming at a 2°C increase, more frequent occurrence of an ice-free summer Arctic is expected (around 10-35%) (Mahlstein and Knutti, 2012; Jahn et al., 2016; Notz and Stroeve, 2016). Model simulations show that a temporary temperature overshoot of a warming target has no lasting impact on ice cover (Armour et al., 2011; Ridley et al., 2012; Li et al., 2013).

They have avoided the "Discussion", not the projections.

41
Arctic sea ice / Re: 2019/2020 freezing season
« on: August 23, 2019, 10:12:04 AM »
I disagree

42
Arctic sea ice / Re: The 2019 melting season
« on: August 22, 2019, 09:35:10 AM »
I doubt this storm will provide much melt,  it is both geographically and temporally in the wrong place for a large melt caused by dispersion or compaction.

The 2012 storm was earlier and over the central Arctic  while this is later and mainly over land.

I'm new to this board and while there is a fantastic amount of data and science on here it surprises me that there is so much desire for melt and records rather than just watching it and learning; it should be about what happens, or potentially happens, not what you want to happen.

From what I can tell, I don't believe many here WANT record lows and melt. Because many here understand what that means for the planet. I think really what it is about is interest.

43
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 01, 2019, 05:53:48 AM »
In order to really beat 2012 this year, the ice is gonna need to melt like crazy. I could very well be wrong, but I am getting the feeling this year will beat out 2016, not 2012.

44
Permafrost / Re: Arctic Methane Release
« on: June 26, 2019, 01:15:02 AM »
Ken Feldman is why I left this thread. He is a toxic clown either trying to pass some hopium agenda or is he to scared of these kind of topics. Ken, I recommend you go back to rambling on about electric cars, because at least there you’re not annoying.

45
Consequences / Re: Worst consequence of AGW
« on: June 05, 2019, 06:57:49 AM »
The worst consequence of climate change? The end of modern civilization and the reduction of the population to historical levels or less. There will be millions of humans around, but they won't be living. They will be surviving on an alien planet. But that only happens if the Arctic collapses and we are as unprepared as we are now. If we mount serious response in time we can completely avoid apocalypse and the opposite will come true. A new era of prosperity awaits.

I would like to answer a spin of this question. What is the most scary consequence of climate change? Heatwaves. Particularly after ASI is gone in the summer, deep inside the continents. The temperatures will rise to levels that no hominid have ever experienced in nature. Powerstations will blow up, rods will melt, metal will buckle. Very few people will survive.

Sure hurricanes and floods can be scary, but at least they are fast. Heatwaves may last weeks. I find it terrifying.

If we take unprecedented actions, I can't say I agree that there will be a "new era of prosperity". We've already baked in enough crap for things to get worse than they are now

46
Permafrost / Re: Arctic Methane Release
« on: June 02, 2019, 08:38:23 PM »
This pretty much confirms more of what I have been saying about methane releases from hydrates, even tho many choose to downplay or ignore

https://m.phys.org/news/2019-05-deep-sea-carbon-reservoirs-superheated.html

47
Science / Re: Magnitude of future warming
« on: May 31, 2019, 10:15:01 AM »
5-6 C. Feedback loops tend to be forgotten often. Tons of people think we just have to stop emitting co2 and then we will be fine, but that is false.

This 5-6 C rise in temp is likely going to wipe out most life on the planet as well as our species.... or at least a large percent of us. Civilization probably has till mid century

49
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: May 15, 2019, 01:52:27 AM »
Saying the arctic will go ice free before 2030 is just as valid as saying it won’t

50
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: May 11, 2019, 10:17:56 PM »
Lets get back on topic, If you want to create a thread for who's right Mann or McPherson please do so.

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