http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

So, the this year’s net melt is already greater than for the 2007 total, and we still have 2-3 weeks to go before it ends, and it has occurred in a La Nina year. Not looking good for the sceptic camp.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

(Hat tip to dhogza at Deltoid.)

Carter has published a long paper in the journal “World Economics” (December, 2006; vol. 7 No. 4) titled: The Stern Report: A dual Critique”. I replied in an article in the same Journal (January 2007, Vol 8, No. 1). Carter did not respond to my reply.

I can send you pdf s of the paper and reply if of interest.

My point and inference to Greg (he has not replied to the direct questions)was that some scientists (eg Bob Carter) have a hidden agenda. Prof Carter goes on the denialist media roadshow and is lauded by the likes of Andrew Bolt and Jenifer Marohasy – but he does not publish his outlandish claims in recognised science journals – one has to ask why not? Hence my assertion that some scientists him have a hidden agenda.

Barry on the other hand is up front about all these issues – with no hidden agenda. In fact, I would say he has all the qualities that any good scientist practises and which you have alluded to – to do otherwise is anathema to their very being.

Thanks very much for the excellent sources. If I may say to you all, despite the intrusion of people like Greg 21 (and they rarely identify themselves), please keep up this blog. Nothing will change the denialists opinions but it is very useful for the rest of us to have links to reliable data.

I should add that I am a civil engineer and one of the issues that I worry about (apart from solving this problem!) is that I am asked for advice now on what allowance we should make for sea level rise in the design of major new infrastrucure, which often will have an economic life of 30 to 50 years or more. There is little guidance. If we apply normal principles of engineering risk management, for an event causing severe harm we should already be designing for it even if it is merely possible (but unlikely). Yet we are not designing adequately for the current most likley projection let alone any worst case scenario.

The URL for the Wilkins ice shelf melting is http://www.sciencedaily.com/releases/2008/06/080613104743.htm
I also downloaded an image from the 9-7-08 for the Ross ice shelf. I have the image but can not locate the URL at the moment.

Regarding motivation for denial – the single most informative piece I have read is by Monbiot in his book ‘Heat’ http://www.guardian.co.uk/environment/2006/sep/19/ethicalliving.g2

Here is the introduction to his article in The Guardian September 19 2006

The denial industry

For years, a network of fake citizens’ groups and bogus scientific bodies has been claiming that science of global warming is inconclusive. They set back action on climate change by a decade. But who funded them? Exxon’s involvement is well known, but not the strange role of Big Tobacco. In the first of three extracts from his new book, George Monbiot tells a bizarre and shocking new story

With respect to you last line, I have been wrestling with several recalcitrants on another blog who still think that there is no proof of the HIV/AIDS connection, or indeed that the virus itself exists. In this case it seems to be a perverse psychology that drives the belief, to the extent that the holders of this notion are resistant to any and all attempts to genuinely, and without malice (growing crakiness on my part is a different thing), enlighten them.

I am beginning to think that anyone without appropriate qualifcations, who asks an expert if said expert has an agenda, has an agenda of their own, whether rooted in vested interest or in psychopathology.

No guesses which blog it is…

Andrew: can you give me more info on the Ross ice shelf? Are you sure you don’t mean the Wilkins?

1. Oxygen isotopes of ice cores and marine plankton indicate temperatures about 7500-8000 years ago were lower than at present by about 0.3 – 0.4 degrees C.
2. At that time a gradual to intermittent decline commenced toward the next glacial cycle.
3. Following rise of CO2 and CH4 at 11 270 years-ago greenhouse gas levels stabilized at a maximum of 300 ppm CO2. By contrast they are now rising at rates of 2.4 ppm/year (2007) and have reached levels of 387 ppm — some 40% higher than peak interglacial levels over the last 640 000 years.
3. An increase of 1 ppm CO2 in the atmosphere equates approximately in +0.01 degree C temperature rise.
4. The ice sheets formed in the late Eocene (about 34 million years ago) when CO2 levels declined below 450 ppm. Currently CO2-equivalent levels (a value including CH4 forcing) is 433 ppm.
5. Consistent with the rise in GHG/radiative forcing levels, the ice sheets are melting at exponential rates, including west Antarctica, where for the first time the Ross ice shelf has been observed to break up during the southern winter.
6. Sea level has been rising from rates of 0.5 mm/year early in the 20th century to 3.5 mm/year in 2007. Total melting of Greenland and west Antarctica ice melting track toward 14 metre sea level rise.

The above is documented by direct ground and satellite observations reported by major science organizations and hundreds of publications.

Do climate scientists have an agenda?

Of course we do — namely the professional duty of scientists to report observations arising from their research which may give rise to concern for societies, very much as medical doctors do. In othe words, an agenda identical in principle to than those of scientists who pointed out to the ozone depletion, or to the consequences of tobacco smoking, or to the aids virus, and were heavily criticized — including ad-hominem – by vested interests.

So I’m curious – to what part of the NOAA Geophysical fluid dynamics laboratory website were you referring? Or alternatively, which scientific paper which stated this and/or reviews the large body of evidence you claim makes this an uncontroversial and undisputed issue?

But even without this evidence to back up your claim, the broad answer is clear enough. The forcing effect in the mid-Holocene optimum was a slight difference in the orbital parameters, and was concentrated in the northern low latitudes — hence the more pronounced regional impacts. Now, the forcing via fossil carbon are global, and on that scale are considerably more important in influencing the planetary climate system.

A tipping point is only tipped is the system is primed for it.

However, humanity has never before conducted an ‘experiment’ as we have been. Considering there is robust and rigorous evidence suggesting humanity is largely responsible for this ‘current’ change in climate, it would be prudent to tread with caution.

We only have one ‘test-tube’ to conduct our experiment in, the ‘alarmists’ on BOTH sides of the fence should pull their head in. What is required (as always) is dedicated and rational scientific discipline.

Unfortunately, there are those that ‘contaminate’ the science by their political ideology, their economic rationalism or their ignorance, the antithesis of good science.

Where do you stand? Do you think Barry Brook or those like him have a hidden agenda?

In order to preserve their credibility, those who wish to:

- Predict that the albedo effect of losing the Arctic ice cover in summer will push the global climate over a “tipping point” that leads to a catastrophic climate change need to explain why this did not happen 7,000 years ago.

- Frighten children with predictions of massive, world-ending outbursts of methane hydrates from the floor of the Arctic Ocean need to explain why that did not happen 7,000 years ago.

- Predict the extinction of the polar bear need to explain why an animal shown to have evolved to its modern form 12,000 to 20,000 years ago, still exists when its summer hunting grounds were completely disrupted 7,000 years ago.
____

What exactly is this ‘catastrophe’ that is supposedly happening?

The benefit to their shipping costs would be awesome.

The soot fallout in the Arctic from diesel ship engines would also.

NASA satellite gravity and microwave measurements indicate a doubling of Greenland ice melt areas per decade (NASA 2006). Rates of ice loss of the Greenland ice sheet have increased from 0.05+0.12 mm/year during 1961 – 2003 to 0.21+0.07 mm/year during 1993 – 2004. The measurements indicate an increase in ice-sheet melt area by 16% from 1979 to 2002 (Steffen & Huff 2002; Steffen et al. 2004; NASA 2006; Hanna et al. 2005; Thomas et al. 2006; IPCC 2007; Hansen et al. 2007a).

HANNA H., HUYBRECHTS P., JANSSENS I., CAPPELEN J., STEFFEN K. & STEPHENS A. 2005. Runoff and mass balance of the Greenland ice sheet: 1958 – 2003. Journal of Geophysical Research 110,
D13108.
STEFFEN K. & HUFF R. 2002. A record maximum melt extent on the Greenland ice sheet in 2002. Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado at Boulder.
STEFFEN K., NGHIEM S. V., HUFF R. & NEUMANN G. 2004. The melt anomaly of 2002 on the Greenland Ice Sheet from active and passive microwave satellite observations. Geophysical Research Letters 31, L20402, doi:10.1029/2004GL020444.
THOMAS R. E., FREDERICK W., KRABILL S. & MARTIN C. 2006. Progressive increase in ice loss from Greenland. Geophysical Research Letters 33, L10503, doi:10.1029/2006GL026075.

I have a question in light of this – does anyone know what progress is being made on models of large ice sheet melting? The obvious (to me) implication is that Greenland will also start melting faster. I presume that as it becomes less surrounded by Arctic ice it is more exposed to warmer air and water and hence will melt more quickly? Or is that not how it works? One of the things I have found most frustrating in the (scientific) global warming debate is the uncertainty about forecasts of sea level rise. Intuitively the IPCC4 forecasts seemed very low.