Hi Andrew,
Re July's Scientific American, I assume you are referring to "The Last
Great Warming" [1], at the PETM about 56 million years ago, and that
today's AGW is much faster. Yes I'd read that. There are some good
quotes:
"The speed of today's rise (in greenhouse gases) is more troubling than
the absolute magnitude."
"Scientists worry that methane belches from the thawing Arctic could
greatly augment today's fossil-fuel-induced warming."
"As the deep sea warmed, its oxygen content dwindled... These changes
spelled disaster for certain microscopic organisms called
foraminifera... 30 to 50 percent of those species went extinct"
The speed of warming is crucial as regards the methane, because of its
short lifetime in the atmosphere. But if it is vented in large
quantities, then the ability of tropical OH to cope with oxidising the
atmospheric methane could jeopardised, resulting in a much longer
lifetime for methane. Furthermore there are indirect radiative forcing
effects which increase as the level of methane rises, see paper by
Isaksen et al. [2]
(BTW Prof Isaksen has accepted my invitation to the London methane
workshop 3-4 September.)
We can also expect a reduction in biodiversity as water warms globally
at all depths. I've mentioned this in connection to the Arctic in a
separate email. Oxygenation of water could be a key factor - so keep
the ideas coming in!
Cheers,
John
[1]
http://www.scientificamerican.com/article.cfm?id=the-last-great-global-warming
[2] http://www.agu.org/pubs/crossref/2011/2010GB003845.shtml
---
On 03/07/2011 17:25, Andrew Lockley wrote:
Have a look at sci am this month for an alternative viewpoint. I'd
send to list but dont with to get my ear bent again for posting too much.
On 2 Jul 2011 02:03, "John Nissen" <[email protected]
<mailto:[email protected]>> wrote:
>
> Hi Andrew,
>
> I hope you are enjoying the IUGG conference in Melbourne. I stayed a
> few days near Melbourne on a "down under" holiday last October.
>
> Thanks for your very cryptic email. I'm not sure what you referred to
> as being so "bloody important". Yes, methane is bloody important. And
> so is our workshop, 3-4 Sept in London, to brainstorm on averting a
> methane catastrophe! It would be good to get an expert on permafrost
> to the workshop.
>
> You are welcome to advertise the workshop at the conference, but note
> that I am looking for people with ideas to contribute to the
> brainstorming - not just with useful expertise.
>
> I eventually found the talk you mentioned about PETM in the IUGG
> programme [1]:
>
> /"Methane and environmental change during the Paleocene-Eocene thermal
> maximum (PETM): Modeling the
> PETM onset as a two-stage event" by L. Mysak, D.A. Carozza, G.A.
Schmidt./
>
> Are they saying it happened in 50 years, because I've read elsewhere
> that it happened much slower than today [2]. Sam Carana and I are
> concerned that the methane could trigger runaway global warming. And
> this could happen quite suddenly, perhaps within two decades,
especially
> with a seasonally sea ice free Arctic very likely this decade.
> Declining summer snowfall is providing further positive feedback.
>
> So here are two important talks tomorrow:
>
> 0915 # 2851. "The Current and Future State of Permafrost in CESM
> [Community Earth System Model]" A. Slater, D.M. Lawrence, S.C. Swenson.
>
> 0930 # 624. Invited "Declining Summer Snowfall in the Arctic: Causes,
> Impacts and Feedbacks" J. Screen, I. Simmonds.
>
> David Lawrence of NCAR is a top expert on permafrost [3]. Albert and I
> went to a talk of his at Reading University a few years ago. David
> thinks that permafrost will all go once the sea ice has gone. He's (or
> he had) been assuming that sea ice is cyclic - so current retreat will
> reverse. I don't suppose he'll be at the conference - since Andrew
> Slater of NSIDC appears to be giving the talk. But if either of them
> could come to our workshop, that would be great. Please talk to Andrew
> if you get a chance.
>
> BTW, are you staying to the end of IUGG on 7th July?
>
> Cheers,
>
> John
>
> [1] http://www.iugg2011.com/pdf/IUGG2011_FinalEntireProgram.6June.pdf
>
> [2]
>
http://www.skepticalscience.com/co2-rising-ten-times-faster-than-petm-extinction.html
>
>
> [3]
>
http://www2.ucar.edu/news/933/permafrost-threatened-rapid-retreat-arctic-sea-ice-ncar-study-finds
>
>
> ---
>
> On 01/07/2011 00:02, Andrew Lockley wrote:
>> john
>>
>> bloody important
>>
>> just seen a talk on petm in oz.
>>
>> looks like it happens in just 50 years. this is massive news.
>>
>> look up the talk. last session Thursday
>>
>> thanks
>>
>> a
>>
>> On 30/06/2011, John Nissen<[email protected]
<mailto:[email protected]>> wrote:
>>> To: Professor John Walsh, President's Professor of Climate Change&
>>> Chief Scientist, IARC
>>> Date: 30 June 2011
>>>
>>>
>>> Dear Professor Walsh,
>>>
>>> I am seeking specific additional expertise for a workshop to be
held 3-4
>>> September in London, concerning the Arctic methane threat to climate
>>> change and how to counter it quickly. The International Arctic
Research
>>> Centre has unique expertise on the East Siberian Arctic Shelf, which
>>> would be particularly valuable.
>>>
>>> [snip]
>
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