“Per the scientific consensus with respect to global warming, CO2 is the primary initiating driver, but there are other drivers as well, including other greenhouse gases, and, to a much smaller degree, the sun.”

First of all, the “scientific consensus” does not mean much. It just confirms that this is the current “paradigm” among a majority of “scientists” involved in climate study. No more, no less. Paradigms shift as new information is gleaned. Since there has been no physically observed validation of the paradigm as yet (as opposed to computer model outputs), it has still to be proven.

Secondly, there is a growing number of scientists who question that CO2 is the “primary driver”. Most agree with the basic greenhouse hypothesis (Arrhenius, Stefan-Boltzmann), which states that a doubling of CO2 should result in an increase of temperature of around 0.7C. But there is major disagreement on the assumed positive “feedbacks” used in climate models, which increase this impact by a factor of 4+ to 3.0C.

Thirdly, there have been many studies that show that the sun may be playing a much more important role in climate change than previously assumed, so the statement “to a much smaller degree, the sun” is questionable. Studies are underway at CERN that may result in a basic “paradigm shift” on the relative importance of the sun in climate change.

Max

delosgatos has shown us the subtle difference between a "theory" and a "hypothesis".

The greenhouse hypothesis is just that: a yet to be validated hypothesis or postulation. GCMs (computer climate models) do not validate a hypothesis. It takes physically observed hard data to validate the greenhouse hypothesis, and this is lacking today.

To follow the lead article author's suggestion to base far-reaching and exremely costly policy decisions on an unproven hypothesis "just in case" is absurd.

Just john wrote: “I tend to believe that humans are the primary cause of global warming, but I suspect that humans will NOT solve it.”

You're probably wrong on part 1 but certainly right on part 2.

Falhaar wrote: “The weather for this year was extremely unusual and there has been a massive decrease in old core ice as well as the thickness of the ice. Much of the arctic is now less than one year old!. As you'd no doubt know, the surface of the water is much easier to freeze than the deep and it is the loss of the deep core ice which is a forewarning of some serious shit in the future.”

Yep. “The weather for this year was extremely unusual.”

Arctic sea ice extent for May 2008 was 13.18 million square kilometers, reaching the same level as in May 1989.

This is 2.5% below the baseline level (1979-2000 mean May level of 13.6 million square kilometers), around 3% above the May 2007 extent and around 4.5% above the record May low reached in May 2004.

The linear average rate of decline is 3.0%/decade (over the 30-year period since measurements have started). If the decline continues at this rate, it will take 330 years for the entire Arctic sea ice to disappear.

The most recent decline has however not continued at the 3.0%/decade rate, since the May 2008 extent is back to the May 1989 extent (i.e. zero net decline in 19 years).

http://nsidc.org/data/seaice_index/images/n_plot_hires.png

A February report shows that it has not only expanded its extent by 2 million square km over the average of the past 3 years, it has also gained in thickness, by about 10-20 cm over last year. That’s a major increase in total volume.

http://www.cbc.ca/technology/story/2008/02/15/arctic-ice.html

Less than one year old? Yep. That’s what they call “seasons” (like winter, spring, summer, etc.). Happens all the time.

“Forewarning of some serious s… in the future?”

This sounds like some “serious bulls… for the future” to me.

Sorry for cutting in to your exchange with Falhaar, who wrote: “And I don't know where you're getting your ‘global temperature remains flat’ data from, but I'd be curious to see your source.”

The source, Falhaar, are all those pesky thermometers out there, even the ones next to asphalt parking lots and AC exhausts.

The four temperature records all show a flat to slight cooling trend from 1998 to today (or from 2001, if you don’t want to start the trend with the all-time record ENSO year 1998).

I’ll link the four records separately, so they don’t get hung up in the spam filter of this site.

Read ‘em and weep (or rejoice).

Plateau – Hadley

http://farm4.static.flickr.com/3134/2591260894_011a1a6c9c_b.jpg

Plateau – GISS

http://farm4.static.flickr.com/3232/2590412265_d7f734577c_b.jpg

Plateau – RSS

http://farm4.static.flickr.com/3125/2591268046_fa0d4057e9_b.jpg

Plateau – UAH

http://farm4.static.flickr.com/3108/2590437485_805bc7a960_b.jpg