Hi Alastair,
The scientific evidence is strong/overwhelming that the situation in the
Arctic has become extremely dangerous, but risk can be significantly
reduced by taking measures to cool the Arctic, including
geoengineering. The faster these measures can be taken, the less the
risk. (Reducing CO2 emissions is desirable but cannot have much effect
on the Arctic in the necessary timescale.)
What you are not taking into account is the rapid retreat of sea ice,
with a clear trend towards having an Arctic Ocean with little or no sea
ice for one month by 2015 or 2016, and little or no sea ice for six
months within a decade. This trend is clear by looking at the PIOMAS
sea ice volume data. (However, astonishingly, the Hadley Centre deny
the credibility of this data because it does not fit their models. Our
group, AMEG, has written about this here [1].)
The lack of sea ice is driving up the Arctic temperature, especially the
water temperature over the continental shelf areas, where there is much
methane to be released. The rate of warming, already much above the
global average, will no doubt increase dramatically as the sea ice
extent collapses within the next few years. This is the main reason
that people are fearful of the methane - it is indeed like a time bomb,
waiting to go off. The methane threat is real because there is evidence
that gigatons of methane (~1% of the total undersea methane stored)
could be released at any time in the next few years from the seabed
north of Siberia, where the seabed has been warming significantly. The
methane being released there in ever larger plumes IS reaching the
atmosphere, and the atmospheric level over the Arctic Ocean DOES appear
to be increasing, e.g. as shown in comparative images here, see figure 3
[2].
I am aware of the denial of danger from RealClimate, though have not yet
responded to counter their claims that there's nothing to be worried
about, that they've also made in the past (with David Archer mainly
responsible).
But we must remain positive. It is no use denying the danger, burying
our heads in the sand, or just procrastinating. We can and we must act
quickly. Then we have an excellent chance to prevent a deteriorating
situation getting completely out of hand.
Cheers,
John
[1]
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/writev/171/arc31.htm
[2]
http://a-m-e-g.blogspot.co.uk/2012/05/message-from-arctic-methane-emergency.html
[3]
http://www.realclimate.org/index.php/archives/2012/06/methane-game-upgrade/
--
On 16/07/2012 04:54, Alastair McIntosh wrote:
> John ... I cannot help continuing to feel that you are trying to push us all
> down the road of geoengineering on the basis of an apocalyptic argument
> ("Isn't that going to be the obituary of the human race? "They had the
> technology, but didn't have the guts to use it."") that is not adequately
> backed up by the science. I have previously put my case, that you have never
> adequately answered, based on the failure of the alleged Arctic methane bomb
> to show up (as yet) in atmospheric methane measurements. May I draw your
> attention to this post on RealClimate,
> http://www.realclimate.org/index.php/archives/2012/06/methane-game-upgrade/
> and particularly its paragraph:
>
> "The methane emission fluxes are higher than previous estimates, but that's
> not really the most important point, because emissions from the Arctic are
> small relative to low-latitude wetlands, and doubling or even nearly
> quadrupling the Arctic fluxes (in one of their analyzed regions), they would
> still be small in terms of global climate forcing. And the lifetime of
> methane in the atmosphere is short, about 10 years, so methane doesn't build
> up like CO2, SF6, and to a lesser extent N2O do."
>
> What is your response to this? Can you demonstrate that the urgency with
> which you and AMEG are pushing Arctic methane is not just barking up an
> unproven tree? In any case, geoengineering that allows carbon emissions to
> keep piling on because we are using a methadone in place of treating the
> addiction is only going to compound our problem, because it might (if it
> works) let us off the hook a little while longer, but masks the pain and so
> feeds the addiction.
>
> I'm sorry to bang on about this question of needing to ground our assertions
> in the peer-reviewed science, but you keep using this list to push
> geoengineering, so I'm looking for greater rigour, not just vigour.
>
> Alastair
>
>
>
> -----Original Message-----
> From: Discussion list for the Crisis Forum
> [mailto:[log in to unmask]] On Behalf Of John Nissen
> Sent: 15 July 2012 06:01
> To: [log in to unmask]
> Subject: Re: Tropical forests spreading?
>
> Hi Tom,
>
> Much though I am critical of Hadley Centre projections, see "calling to
> account" in [1], it is because they are too optimistic. If their models
> suggest that the Amazon rainforest could become a major drought zone, the
> models will no doubt be overoptimistic about the time scale. What I have
> heard is that, if there are two or three years in a row of drought, there
> will be a massive die-off of trees, and the danger of a firestorm destroying
> a major part of the forest. If that is true, then we have a planetary
> emergency which, like that caused by disappearing Arctic sea ice, will not
> be acknowledged by the climate change community.
> Similarly the only possible action to get us out of this dreadful situation
> is through geoengineering. But the climate change community and
> environmentalists continue to wring their hands while saying that
> geoengineering is premature.
>
> Why is it that humans require a major disaster before action is taken?
> Isn't that going to be the obituary of the human race? "They had the
> technology, but didn't have the guts to use it."
>
> John
>
> [1]
> http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/writev/1
> 71/arc31.htm
>
>
> --
>
> On 13/07/2012 16:05, Barker, Tom wrote:
>> The Amazon will be a major drought zone if the Hadley projections are
> correct. They show that the forest has had it unfortunately. Tom
>> ________________________________________
>> From: Discussion list for the Crisis Forum [[log in to unmask]]
> on behalf of Byron Smith [[log in to unmask]]
>> Sent: 13 July 2012 15:52
>> To: [log in to unmask]
>> Subject: Re: Tropical forests spreading?
>>
>> Greetings all,
>>
>> If I may return to the Nature paper by Higgins& Scheiter [1] that Prof
> Northcott posted a couple of days ago, having now had a chance to read it, I
> note the following in the penultimate main paragraph:
>> "Although these projections of increasing tree dominance seem to
> contradict studies that project forest dieback in the Amazon, this may
> simply be because our analysis assumes that rainfall remains constant,
> whereas projections of Amazon forest dieback are based on climate
> simulations that project decreased rainfall. The high uncertainty in
> precipitation change over Africa led us to assume that rainfall remained at
> ambient levels (see Supplementary Information), but future studies should
> consider changes in rainfall as well as feedbacks between vegetation and
> rainfall."
>> So while CO2 trumps temperature in shifting ecosystems from C4 to C3
> dominated flora (i.e. savanna/grasslands to forest), hydrological changes
> could well trump them both, as is generally thought to be most likely for
> much of Amazonia. Rhett Butler (Mongabay.com), a leading environmental
> journalists, sought feedback on the paper from a number of Amazon experts
> concerning the applicability of extending this analysis to South America and
> found strong reservations across the board.[2] The hydrological projections
> for Africa that I've seen are indeed mixed, but more recent ones seem to
> point to some significantly lower levels of precipitation for southern
> Africa in particular.[3]
>> And both the opening and final paragraph of the Higgins& Scheiter piece
> note that land use changes are a further wildcard.
>> So, yes, acknowledging the complexity of global change trajectories
> involves honesty about possible negative feedbacks slowing rates of change,
> as well as appreciating the resilience and adaptability of both natural and
> human systems. And invoking apocalyptic language and imagery in the
> discussion of ecological crises confuses both the relevant science and (I
> would argue) theology. On all this I agree with Michael. But this particular
> study has some fairly major caveats to observe before it might give us too
> much hope of a soft landing.
>> We're not out of the woods (or rather, back into them) yet.
>>
>> [1]
> http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11238.html
>> [2]
> http://news.mongabay.com/2012/0712-telegraph-poor-science-journalism.html
>> [3] For example:
> http://journals.ametsoc.org/doi/pdf/10.1175/2009JCLI2317.1.
>> Regards,
>> Byron Smith
>>
>> PhD candidate
>> University of Edinburgh
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