Near Term Human Extinction

[TerryM]

When listening to the video it's within the 8th min. that he mentioned the possibility of a 5C-6C temperature rise within 2-3 decades but states that massive methane release would be required for this scenario to play out.

I frankly didn't hear anything terribly alarmist in the piece except possibly it's title. A more appropriate title might be "Why I believe geoengineering and natural feedbacks preclude any possibility of near term human extinction".

 

Terry

[skierinvermont]

 

Just to finish the quote from Marcott et al

 

Current global temperatures of the past decade have not yet exceeded peak interglacial values

but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel

on Climate Change model projections for 2100 exceed the full distribution of Holocene

temperature under all plausible greenhouse gas emission scenarios.

All plausible greenhouse gas emission scenarios include some in which temperatures don't rise very much in comparison to the most likely scenarios.

 

While Ellesmere Island driftwood carbon dating is usually referenced to show that the ice shelves have been in place for the past 5,500 years they can also give evidence that the Arctic Ocean was perennially frozen from as early as 9,900 BP Calendar yrs.

If the Arctic had not been frozen the trees would have become waterlogged and would have sunk. Perennial ice was required for rafting them across from the Siberian rivers. If the ice had only frozen seasonally they could not have made the voyage.

Since we appear to be nearing a period when seasonal ice will become the new norm it's fair to say that we're rapidly approaching a time when the Arctic Ocean will be provably warmer than at any time in the last 9,900 years.

It is feasible that seasonal ice could have occurred for short periods between 9,900 & 5,500 yrs.ago, but any extended period would show as a clear break in the deposition of the wood.

http://dro.dur.ac.uk/6877/1/6877.pdf

Terry

 

 

 

The England et al. paper doesn't draw the same conclusion you do. I think you are assuming that ice is necessary for the driftwood transport. I read it and I don't see them say that anywhere and they definitely do not conclude continuous perennial sea ice during the Holocene. 

 

Numerous papers conclude the opposite and find much of the early-mid Holocene lacked perennial arctic sea ice.

 

See:

Vare et al 2009

Hanslik et al 2010

Funder et al 2011

Muller et al 2012

[skierinvermont]

When listening to the video it's within the 8th min. that he mentioned the possibility of a 5C-6C temperature rise within 2-3 decades but states that massive methane release would be required for this scenario to play out.

I frankly didn't hear anything terribly alarmist in the piece except possibly it's title. A more appropriate title might be "Why I believe geoengineering and natural feedbacks preclude any possibility of near term human extinction".

 

Terry

 

Except that such a methane release is not a real possibility. Saying it is, is alarmist and untruthful.

[tamarack]

 

His understanding of the 35C @ 100% humidity situation is different than my own. He seems to feel that it's survivable if no work is done & my understanding is that it's lethal regardless of activity level. A minor point since it's easy to assume that if no one is capable of doing anything the group dies quite rapidly from starvation.

Terry

 

IMO, lethal w/o activity is probably too pessimistic. Part of my rationale comes from seeing data from a few oil ports in the Persian Gulf, which show summertime TDs often in the 30-33C range. Folks there are doing heavy labor and very few are in AC spaces, so I don't think another couple degrees of dewpoint would change ugly to lethal. I'd also rather not have to find out.

[TerryM]

 

 

IMO, lethal w/o activity is probably too pessimistic. Part of my rationale comes from seeing data from a few oil ports in the Persian Gulf, which show summertime TDs often in the 30-33C range. Folks there are doing heavy labor and very few are in AC spaces, so I don't think another couple degrees of dewpoint would change ugly to lethal. I'd also rather not have to find out.

You're right about 35 TD not being lethal but dew point isn't the same as wet bulb.

 

Wet bulb is primarily used in HVAC calculations where dew point is used by meteorologists.

 

Terry

[TerryM]

The England et al. paper doesn't draw the same conclusion you do. I think you are assuming that ice is necessary for the driftwood transport. I read it and I don't see them say that anywhere and they definitely do not conclude continuous perennial sea ice during the Holocene. 

 

Numerous papers conclude the opposite and find much of the early-mid Holocene lacked perennial arctic sea ice.

 

See:

Vare et al 2009

Hanslik et al 2010

Funder et al 2011

Muller et al 2012

As I'd said the paper wasn't addressing this point at all. How does one explain the transport of logs from Siberia to Ellesmere Island without evoking ice rafting & how is an ~3 yr voyage possible if all the ice melts in the summer?

 

We haven't reached an ice free summer yet, but most consider it likely within a relatively short time.

 

Your conclusions re.Arctic methane release are simply speculative at this stage. Both the US and the Russians were concerned enough to send S&S on an extensive, expensive voyage to the ESAS to verify the reports they were receiving of  the "boiling ocean" in the area. If "methane release is not a real possibility" why is such research have been conducted?

 

Terry

[skierinvermont]

As I'd said the paper wasn't addressing this point at all. How does one explain the transport of logs from Siberia to Ellesmere Island without evoking ice rafting & how is an ~3 yr voyage possible if all the ice melts in the summer?

 

We haven't reached an ice free summer yet, but most consider it likely within a relatively short time.

 

Your conclusions re.Arctic methane release are simply speculative at this stage. Both the US and the Russians were concerned enough to send S&S on an extensive, expensive voyage to the ESAS to verify the reports they were receiving of  the "boiling ocean" in the area. If "methane release is not a real possibility" why is such research have been conducted?

 

Terry

 

1) I don't know how it is possible but I can think of a few ideas. You're the one making the assertion that the Holocene has had continuous or near-continuous perennial sea ice. Prove to me that deposition of Ellesmere cannot occur without perennial sea ice. You presented this as fact. As it turns out the paper doesn't conclude continual perennial sea ice, and it doesn't even say that deposition on Ellesmere requires perennial sea ice. I gave you 4 peer-reviewed papers that say sea ice was NOT perennial during the HCO. You gave me a personal assumption about driftwood which you incorrectly presented as fact.

A couple ideas for why perennial sea ice might not be required for deposition:

a) The logs are big enough and bound by ice for 9-10 months of the year so they don't sink and are eventually washed up on Ellesmere.

b. The logs may be able to be blown fairly quickly towards Ellesmere when there is no ice because of the large fraction above water.

c) I know for a fact that logs and animals have traveled farther distances across oceans.

 

2) My conclusions re: methane are not my conclusions. They are the conclusions of dozens of researchers on the subject and peer-reviewed papers. A large 'methane bomb' is not a serious probability. There's no plausible mechanism by which it could occur. The deposits are deep within the seabed which will warm very very slowly (much slower than even the water above the seafloor). 

 

 

3) The fact that the U.S. and Russia send researchers to the arctic to do research on methane emissions doesn't have anything to do with the possibility of a large methane bomb. Learning about the current rate of emissions and exactly how much of the deposits are close enough to the surface to be released in the next 500+ years is of significant scientific interest. This is just more unsubstantiated assumption on your part. Provide some real scientific evidence that there are substantial amounts of methane close enough to the surface of the sea floor to be affected in the next 30, 50 even 100 years. Provide some real scientific evidence that the plumes of methane in the arctic have anything to do with the modern warming period. Of course if you actually do any serious reading on this subject other than reading the alarmist comment sections of certain blogs, you'll find there is no evidence for either of those assertions but plenty of evidence to the contrary.

 

4) I said 'such a methane release is not a real possibility' I didn't say 'methane release is not a real possibility.' The word such referred to a large methane 'bomb.' Not including this quoted portion appears to significantly distort my meaning.

[tamarack]

You're right about 35 TD not being lethal but dew point isn't the same as wet bulb.

 

Wet bulb is primarily used in HVAC calculations where dew point is used by meteorologists.

 

Terry

Your post to which I responded had "35C @ 100% humidity", which is 35C TD. Wet bulb was not mentioned at all, so I'm not sure why it's being introduced now in response to my post.

Please note that my comments on heat/lethality are not meant to refute AGW. They stem from a concern that the more alarmist statements offer deniers too much material in the public discussions.

[TerryM]

Your post to which I responded had "35C @ 100% humidity", which is 35C TD. Wet bulb was not mentioned at all, so I'm not sure why it's being introduced now in response to my post.

Please note that my comments on heat/lethality are not meant to refute AGW. They stem from a concern that the more alarmist statements offer deniers too much material in the public discussions.

Apologize if I hadn't mentioned wet bulb. The study from a few years back had been on the effects of 35C wet bulb temperatures which is what I believe he was referring to.

 

Terry

[TerryM]

The maximum periods of buoyancy likely range from

6 to 10 months for most of the deciduous wood, but for larch

and pine, it averages 9–10 months, and up to 17 months for

spruce [Häggblom, 1982]. Deciduous wood often sinks before entering the Arctic Ocean, or at least before its inclusion

into the ice. All driftwood needs to be transported in or on

the ice, mainly following the ocean currents to reach these

Arctic sites where sampling took place (Figure 1)

http://www.wsl.ch/fe/landschaftsdynamik/dendroclimatology/Diplomarbeiten/Hellmann_etal.2013_JGR-B

 

From your own source:

"Driftwood cannot float across the water, it has to be ferried across the ocean on ice, and this voyage takes several years, which means that driftwood is actually a signal of multi-year sea ice in the ocean and it is this ice that is at risk at the moment" said Dr Funder.

 

So my assertions are hardly "a personal assumption about driftwood". The literature is rife with such statements, I'm amazed that you would even question something so widely accepted.

 

I am interested as to what sites you consider to be the "alarmist" blogs that I follow. Neven's Forum, Nevens Blog, Dr. Roots Blog at Wunderground & occasionally this forum make up the list. While any or all of the above might be considered alarmist by the WUWT crowd most consider them to fairly factual.

 

If you mean to imply that I'm alarmed by what has already transpired on the climate front, or that I'm alarmed at what I fear will be the outcome as long as the world refuses to even acknowledge the state we are in I'll plead guilty as charged. I don't consider this an alarmist position but rather a realistic one.

 

When I first took an interest in the Arctic ice the alarmist position was that it could be gone in the summer in as little as 100 years. The goal posts have moved significantly since that time.

 

Your position here appears to be that we don't have to worry because a rapid increase in Arctic Methane won't happen because it didn't happen during the HO. S&S's papers on this possibility have been dissected here in the past. Paul's position is that we shouldn't worry because natural feedbacks may kick in, geoengineering schemes will prevent it & that we won't experience a 5C-6C jump in temperature within 30 years unless there is a Methane spike.

 

Why would you consider his position alarming as opposed to your own?

 

Terry

[skierinvermont]

You're right. I shouldn't have said 'alarmist.' I should simply have said 'anti-scientific' (with an affinity for the alarming). 

 

I really don't care what you have to say on the subject unless you can give some peer-reviewed critique of the widely accepted probability that there was not perennial arctic sea ice during the HCO.

[csnavywx]

 

 

IMO, lethal w/o activity is probably too pessimistic. Part of my rationale comes from seeing data from a few oil ports in the Persian Gulf, which show summertime TDs often in the 30-33C range. Folks there are doing heavy labor and very few are in AC spaces, so I don't think another couple degrees of dewpoint would change ugly to lethal. I'd also rather not have to find out.

Almost nobody does heavy labor during those periods. If they do, it's with extremely frequent breaks. Trust me, I used to live there.

 

The highest dewpoint I ever saw when I was stationed at Bahrain was 86F (30C) with a temp of 95 (Equates to a Tw of 32.5C). No wind. I was soaked through my clothing with sweat just walking the six blocks to base and had early onset symptoms of heat exhaustion. I was in my early 20s, in great shape, and acclimated to it. There are no words to describe what a 32+ Tw feels like, other than all-consuming, suffocating heat. No, it's not livable without AC for the vast majority of people. Hell, during the summer, it was mandatory to have a camelpak on your person at all times when traveling outside on the base.

 

Luckily this is confined to a few small areas at present. After 2-3C warming, it won't be. If we're stupid enough to allow 4-5C, then you're talking about losing a significant amount of land for inhabitance by mammals, namely some humid subtropical and tropical areas.

[TerryM]

You're right. I shouldn't have said 'alarmist.' I should simply have said 'anti-scientific' (with an affinity for the alarming). 

 

I really don't care what you have to say on the subject unless you can give some peer-reviewed critique of the widely accepted probability that there was not perennial arctic sea ice during the HCO.

I'll be sure to advise Mario, Andreas. Daniel, and all the rest that they're posting at "anti-scientific" sites. I'm sure your opinion will be given the weight it deserves.

 

If you would actually like to read what Dr. Funder wrote it's available at:

http://junksciencecom.files.wordpress.com/2011/08/science-sea-ice-seesaw.pdf

and actually says the opposite of what you have claimed.

 

If you'd like a discussion of the paper I'd direct you to:

http://neven1.typepad.com/blog/2011/08/arctic-tipping-point-may-not-be-reached.html

although this was from 2011 before the ice losses of 2012 & when CO2 was only at 392ppm. You might even find quotes from the  good Dr. himself!

 

If you can find anything in the paper (which I provided for your perusal) that claims an ice free Arctic Ocean during the HCO I'd love to see it - but I won't hold my breath. Remember this is a paper that you claimed supported your position that the Arctic had been seasonally ice free during HCO. Posting a list of names and claiming they agree with you - especially when it turns out that they don't - doesn't add much to the discussion. Claiming that this site has a higher standing within the scientific community than either of Neven's sites is just silly.

 

Terry

[skierinvermont]

I'll be sure to advise Mario, Andreas. Daniel, and all the rest that they're posting at "anti-scientific" sites. I'm sure your opinion will be given the weight it deserves.

 

If you would actually like to read what Dr. Funder wrote it's available at:

http://junksciencecom.files.wordpress.com/2011/08/science-sea-ice-seesaw.pdf

and actually says the opposite of what you have claimed.

 

If you'd like a discussion of the paper I'd direct you to:

http://neven1.typepad.com/blog/2011/08/arctic-tipping-point-may-not-be-reached.html

although this was from 2011 before the ice losses of 2012 & when CO2 was only at 392ppm. You might even find quotes from the  good Dr. himself!

 

If you can find anything in the paper (which I provided for your perusal) that claims an ice free Arctic Ocean during the HCO I'd love to see it - but I won't hold my breath. Remember this is a paper that you claimed supported your position that the Arctic had been seasonally ice free during HCO. Posting a list of names and claiming they agree with you - especially when it turns out that they don't - doesn't add much to the discussion. Claiming that this site has a higher standing within the scientific community than either of Neven's sites is just silly.

 

Terry

 

Funder says that for 2500 years there was no land-fast ice on the north coast of Greenland, and zero multi-year ice south of 83N (the absolute most north tip of Greenland). He also suggests that throughout this period sea ice extent was generally less than half of summer 2007. Less than half 2007 = almost 'ice-free.'

 

I find it unlikely that sea ice was on average this sparse for 2500 years, and there weren't any years with summer minimums less than 1000km2. There were probably whole decades possibly even centuries without perennial sea ice. The fact that perennial sea ice was present only at the most northern tip of Greenland (and even at this location there was some open water and wave action) indicates that on average there was probably not much more than 1000km2 even in good years/decades/centuries.

 

I never said this site is more scientific than Neven's. There probably is more discussion of actual scientific literature on Neven's site. But the interpretation, especially in the comments section by amateurs, is often anti-scientific and alarmist (drawing conclusions not found in the papers themselves, or ignoring points of uncertainty for example). Yet again you are putting words in my mouth. This site is probably even less scientific in general.