[Vision2020] RealClimate.org, 10/6/2009: Climate Change Slowing or Stopping?: 371 Responses!

[Ted Moffett]

As a recent thread on Vision2020 was subject headed, "The Uneducated
American."  This applies spectacularly and alarmingly to climate science,
given the profound disconnect between what the science is informing
regarding the risks of anthropogenic climate change, the opinion trends on
this issue in the public, and the level of integrity displayed in the media
regarding science reporting on climate science.

Only with a motivated and informed body politic demanding action will
politicians and businesses be willing to take the substantial, and in the
short term, possibly expensive and lifestyle altering actions, required to
address climate change.  And given the large percentage of the public that
continues to believe anthropogenic warming a hoax or a blatant scientific
mistake, highly uncertain, or that we can easily adapt to a warming climate,
so why take dramatic action, the odds are discouraging.

The analysis by Rahmstorf, indicates the data does not show any significant
trend demonstrating a break in anthropogenic climate change.  The claims
that this is occurring are sometimes based on managing trend analysis by
cherry picking time start and stop points to create the appearance of stop
in warming (starting the trend at the 1998 intense warm El Nino year, or
Arctic ice extent at the record low 2007 year).  Or cherry picking
weather/climate events that sometimes are an expression of natural
variability (our areas and US recent couple of record daily low
temperatures, a rather minor short term and local climate event given the US
is a tiny fraction of global climate). Or emphasizing events actually caused
in part by anthropogenic warming, though they give the appearance of a
"colder" climate (increased snowfall, increased Antarctic sea ice cover, not
land), and claiming they demonstrate the positive climate forcing from human
impacts, primarily CO2 emissions, are not being expressed as the climate
science community (IPCC, et. al.) has predicted.  Another skeptics talking
point is the expansion of some mountain glaciers, or some areas of Greenland
or Antarctica.  Increased snowfall can contribute to expansion of glaciers
in some cases, though there is exact data that mountain glaciers globally
are losing significant mass over large areas:

Info on NASA/GRACE satellite measurements of glacier mass:

http://www.cnn.com/2008/TECH/science/12/16/melting.ice/index.html
--------
Increased snowfall is predicted due to anthropogenic warming (increased
ocean evaporation causing more precipitation, rain, snow etc.), and
Antarctic sea ice cover is increasing due to a number of causes; but we know
from GRACE (gravity recovery and climate experiment) satellites using
microwave interferometry measuring mass that Antarctica is losing ice mass,
contributing to rising sea levels.  Another common claim is that Arctic sea
ice recovery demonstrates a reversal of global warming; but again this is
based sometimes on starting a trend at the record low extent from 2007,
lower than 2008 or 9, when all three years have the lowest measured Arctic
sea ice cover, and are all well below the 1979-2000 average extent.  Chart
below from the National Snow Ice Data Center showing comparison between
Arctic sea ice in recent years compared to 1979-2000 average:

http://nsidc.org/images/arcticseaicenews/20091005_Figure2.png

NSIDC chart below showing September Arctic ice extent, when minimum is
reached, for years since 1979.  Note the large "recovery" in the middle
1990s.  Evidence that global warming stopped?  No doubt skeptics were
claiming exactly that.  But it was not so...

http://nsidc.org/images/arcticseaicenews/20091005_Figure3.png

Antarctic ice mass loss measured by GRACE:

http://mailman.fsr.com/pipermail/vision2020/2009-August/065696.html
----------
As Rahmstorf points out, it is expected that periods of climate cooling can
occur, even with continued increases in atmospheric CO2 (my wording) as an
increasing positive climate forcing variable, given natural variability.
The current lowering of solar output could contribute to a cooler global
climate.  Indeed, as Rahmstorf emphasized, even with the current low solar
output, the lowest since satellite measurements started in the 1970s, this
past summer revealed the warmest global ocean temperatures, and record
Southern Hemisphere temperature events, which might not be expected given
the solar minimum:

Info on record warm global ocean and Southern Hemisphere summer events:

http://mailman.fsr.com/pipermail/vision2020/2009-September/066090.html

-------
Ironically, human pollution is also cooling the climate, so called "global
dimming," but the positive climate forcings from human activity are
overcoming this negative forcing:

Info on "global dimming:"

http://mailman.fsr.com/pipermail/vision2020/2009-September/066032.html

On 10/14/09, Donovan Arnold <donovanjarnold2008 at yahoo.com> wrote:

>   Global Warming takes a break?
>
> Its because Obama is President. :P
>
> Donovan Arnold
>
> --- On *Wed, 10/14/09, Ted Moffett <starbliss at gmail.com>* wrote:
>
>
>
> From: Ted Moffett <starbliss at gmail.com>
> Subject: [Vision2020] RealClimate.org, 10/6/2009: Climate Change Slowing or
> Stopping?: 371 Responses!
> To: "Moscow Vision 2020" <vision2020 at moscow.com>
> Date: Wednesday, October 14, 2009, 12:02 PM
>
>
> http://www.realclimate.org/index.php/archives/2009/10/a-warming-pause/#more-1265
>  A warming pause? Filed under:
>
>    - Climate Science<http://www.realclimate.org/index.php/archives/category/climate-science/>
>    - Communicating Climate<http://www..realclimate.org/index.php/archives/category/communicating-climate/>
>    - Instrumental Record<http://www.realclimate.org/index.php/archives/category/climate-science/instrumental-record/>
>    - skeptics<http://www.realclimate.org/index.php/archives/category/communicating-climate/skeptics/>
>
> — stefan @ 6 October 2009
>
> Stefan Rahmstorf's bio:
>
> http://www.realclimate.org/index.php/archives/2004/12/stefan-rahmstorf/
>
> The blogosphere (and not only that) has been full of the “global warming is
> taking a break” meme lately. Although we have discussed<http://www.realclimate.org/index.php/archives/2008/12/2008-temperature-summaries-and-spin/>
> this <http://www.realclimate.org/index.php/archives/2008/11/mind-the-gap/>
> topic<http://www.realclimate.org/index..php/archives/2008/04/model-data-comparison-lesson-2/>
> repeatedly<http://www.realclimate.org/index.php/archives/2008/01/uncertainty-noise-and-the-art-of-model-data-comparison/>,
> it is perhaps worthwhile reiterating two key points about the alleged pause
> here.
>  (1) This discussion focuses on just a short time period – starting 1998
> or later – covering at most 11 years. Even under conditions of anthropogenic
> global warming (which would contribute a temperature rise of about 0.2 ºC
> over this period) a flat period or even cooling trend over such a short time
> span is nothing special and has happened repeatedly before (see 1987-1996).
> That simply is due to the fact that short-term natural variability has a
> similar magnitude (i.e. ~0.2 ºC) and can thus compensate for the
> anthropogenic effects. Of course, the warming trend keeps going up whilst
> natural variability just oscillates irregularly up and down, so over longer
> periods the warming trend wins and natural variability cancels out.
> (2) It is highly questionable whether this “pause” is even real. It does
> show up to some extent (no cooling, but reduced 10-year warming trend) in
> the Hadley Center data, but it does not show in the GISS data, see Figure 1.
> There, the past ten 10-year trends (i.e. 1990-1999, 1991-2000 and so on)
> have all been between 0.17 and 0.34 ºC per decade, close to or above the
> expected anthropogenic trend, with the most recent one (1999-2008) equal to
> 0.19 ºC per decade – just as predicted by IPCC as response to anthropogenic
> forcing.
> [image: GISS temperature trends]<http://www.realclimate.org/wp-content/uploads/GISStrends.jpg>
> *Figure 1. Global temperature according to NASA GISS data since 1980. The
> red line shows annual data, the larger red square a preliminary value for
> 2009, based on January-August. The green line shows the 25-year linear trend
> (0.19 ºC per decade). The blue lines show the two most recent ten-year
> trends (0.18 ºC per decade for 1998-2007, 0.19 ºC per decade for 1999-2008)
> and illustrate that these recent decadal trends are entirely consistent with
> the long-term trend and IPCC predictions. Even the highly “cherry-picked”
> 11-year period starting with the warm 1998 and ending with the cold 2008
> still shows a warming trend of 0.11 ºC per decade (which may surprise some
> lay people who tend to connect the end points, rather than include all ten
> data points into a proper trend calculation).*
>
> Why do these two surface temperature data sets differ over recent years? We
> analysed this<http://www.realclimate.org/index.php/archives/2008/11/mind-the-gap/>a while ago here, and the reason is the “hole in the Arctic” in the Hadley
> data, just where recent warming has been greatest.
> [image: Mean temperature difference between the periods 2004-2008 and
> 1999-2003] <http://www.realclimate.org/wp-content/uploads/ncepawrming.gif>
> *Figure 2. The animated graph shows the temperature difference between the
> two 5-year periods 1999-2003 and 2004-2008. The largest warming has occurred
> over the Arctic in the past decade and is missing in the Hadley data.*
> If we want to relate global temperature to global forcings like greenhouse
> gases, we’d better not have a “hole” in our data set. That’s because global
> temperature follows a simple planetary heat budget, determined by the
> balance of what comes in and what goes out.. But if data coverage is not
> really global, the heat budget is not closed. One would have to account for
> the heat flow across the boundary of the “hole”, i.e. in and out of the
> Arctic, and the whole thing becomes ill-determined (because we don’t know
> how much that is). Hence the GISS data are clearly more useful in this
> respect, and the supposed pause in warming turns out to be just an artifact
> of the “Arctic hole” in the Hadley data – we don’t even need to refer to
> natural variability to explain it.
> Imagine you want to check whether the balance in your accounts is
> consistent with your income and spendings – and you find your bank accounts
> contain less money than you expected, so there is a puzzling shortfall.. But
> then you realise you forgot one of your bank accounts when doing the sums –
> and voila, that is where the missing money is, so there is no shortfall
> after all. That missing bank account in the Hadley data is the Arctic – and
> we’ve shown<http://www.realclimate.org/index.php/archives/2008/11/mind-the-gap/>that this is where the “missing warming” actually is, which is why there is
> no shortfall in the GISS data, and it is pointless to look for explanations
> for a warming pause.
> It is noteworthy in this context that despite the record low<http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant>in the brightness of the sun over the past three years (it’s been at its
> faintest since beginning of satellite measurements in the 1970s), a number
> of warming records <http://www.ncdc.noaa.gov/sotc/> have been broken
> during this time. March 2008 saw the warmest global land temperature of any
> March ever recorded in the past 130 years. June and August 2009 saw the
> warmest land and ocean temperatures in the Southern Hemisphere ever recorded
> for those months. The global ocean surface temperatures in 2009 broke all
> previous records for three consecutive months: June, July and August. The
> years 2007, 2008 and 2009 had the lowest summer Arctic sea ice cover ever
> recorded, and in 2008 for the first time in living memory the Northwest
> Passage and the Northeast Passage were simultaneously ice-free. This feat
> was repeated in 2009. Every single year of this century (2001-2008) has been
> warmer than all years of the 20th Century except 1998 (which sticks out well
> above the trend line due to a strong El Niño event).
> The bottom line is: the observed warming over the last decade is 100%
> consistent with the expected anthropogenic warming trend<http://www.pik-potsdam.de/~stefan/update_science2007.html>of 0.2 ºC per decade, superimposed with short-term natural variability. It
> is no different in this respect from the two decades before. And with an El
> Niño developing <http://www.elnino.noaa.gov/> in the Pacific right now, we
> wouldn’t be surprised if more temperature records were to be broken over the
> coming year or so.
> *Update:* We were told there is a new paper<http://www..agu.org/journals/pip/jd/2009JD012442-pip.pdf>by Simmons et al. in press with JGR that supports our analysis about the
> Hadley vs GISS trends (sorry, access to subscribers only).
> ------------------------------------------
> Vision2020 Post: Ted Moffett
>
> -----Inline Attachment Follows-----
>
> =======================================================
> List services made available by First Step Internet,
> serving the communities of the Palouse since 1994.
>                http://www.fsr.net
>           mailto:Vision2020 at moscow.com<http://us.mc447.mail.yahoo.com/mc/compose?to=Vision2020@moscow.com>
> =======================================================
>
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.fsr.com/pipermail/vision2020/attachments/20091014/daac8eb2/attachment-0001.html