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