With 25 years' experience as a professional Earth scientist, I say Earth is extremely complex and messy, difficult to characterize. I would not be surprised to learn of significant holes in currently accepted scenarios. Anyone with solid credentials who's willing and able to look into alternative explanations should be encouraged. For people without qualifications to choose sides and cheer for one side or the other can't help and may hurt. (But when I see a lot of cheering on one side and little on the other--when the issues aren't fully settled--I tend to take the other side to help restore balance.)
Everyone should be able to agree that CO2 is a GHG, that human activities are releasing large quantities of it, and that its atmospheric concentration is rising. The next step, that humans are contributing to global warming by releasing so much CO2, is also quite reasonable. How much global warming we are causing and what contributions there may be from other sources, however, are not fully understood.
It would seem prudent to cut down on the amount of GHG we release, but given national and world economic and political forces and complexities, it's not at all clear to me that any effort we make will have a significant effect on what ultimately happens. Most of the human thought and energy devoted to global warming would probably be better focused on adaptation than control.
Don
----- Original Message -----
From: Alexanian, Moorad<mailto:alexanian@uncw.edu>
To: Kenneth Piers<mailto:Pier@calvin.edu> ; asa@calvin.edu<mailto:asa@calvin.edu>
Sent: Thursday, February 12, 2009 8:44 AM
Subject: RE: [asa] Effect of Solar variability
There is a reference by Scafetta of Foukal's 2006 Nature paper. I am not in this field but was highly impressed with Nicola's presentation. I thought his work is thorough and complete ---Foukal, P., C. Fro¨hlich, H. Spruit, and M. L. Wigley (2006), Variations in solar luminosity and their effect on the Earth’s climate, Nature, 443, 161–166. http://www.fel.duke.edu/~scafetta/pdf/2007JD008437.pdf<http://www.fel.duke.edu/~scafetta/pdf/2007JD008437.pdf>
Moorad
________________________________________
From: asa-owner@lists.calvin.edu<mailto:asa-owner@lists.calvin.edu> [asa-owner@lists.calvin.edu] On Behalf Of Kenneth Piers [Pier@calvin.edu]
Sent: Thursday, February 12, 2009 9:17 AM
To: asa@calvin.edu<mailto:asa@calvin.edu>
Subject: Re: [asa] Effect of Solar variability
Friends: Which refereed research Journal published this paper about solar
irradiance? The findings are almost surely bogus. In the fall of 2006, P.
Foukal's group (Britain) published a paper in Nature in which his group
evaluated solar output data from satellite measurements since 1978 (the first
year that direct satellite measurements of solar irradiance became possible and
probably the best data we have on solar output) . Near the close of their paper
the authors state: “…we can find no evidence for solar luminosity variations
of sufficient amplitude to drive significant climate variations….”. Here is
the citation for anyone who wants to read the paper:
Solar Output
P. Foukal, et.al., Nature, 443, Sept. 14, 161-166 (2006).
These are the same conclusions reached by IPCC in their 2007 report. Their
conclusion is based on a survey of all refereed research papers on this topic
through about 2005 (so would likely not include the Foukal paper). IPCC has
this to say about solar irradiance in their report:
“Changes in solar irradiance since 1750 are estimated to cause a radiative
forcing of +0.12 W/m2. The net radiative forcing from all contributors is 1.6
W/m2, so that changes in solar irradiance accounts for less than 10% of the
climate forcing being measured."
ken piers
Ken Piers
“We can’t solve problems by using the same kind of thinking we used when
we created them.”
A. Einstein
>>> Rich Blinne <rich.blinne@gmail.com<mailto:rich.blinne@gmail.com>> 2/11/2009 8:26 PM >>>
On Wed, Feb 11, 2009 at 11:27 AM, Christine Smith <
christine_mb_smith@yahoo.com<mailto:christine_mb_smith@yahoo.com>> wrote:
>
>
> Nevertheless, like I said, I'd like to do some more digging on it. Perhaps
> Rich and others who are more acquainted with the details of the topic will
> have more to add here?
>
>
This fails the common sense test. Solar variability has been measured since
the 1950s. The Sun varies in the neighborhood of 0.1% following the Sun spot
cycle. http://www.ngdc.noaa.gov/stp/SOLAR/IRRADIANCE/irrad.htmlThere<http://www.ngdc.noaa.gov/stp/SOLAR/IRRADIANCE/irrad.htmlThere> is a
slight climatic effect from this but again it's cyclical. Global warming is
up and to the right which also matches what happens with CO2. Physics Today
is not a peer-reviewed journal while the PNAS most definitely is. Note the
following paper that looked for a long-term trend for Solar variation.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1810336<http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1810336>
Despite the direct response of the model to solar forcing, even large solar
> irradiance change combined with realistic volcanic forcing over past
> centuries could not explain the late 20th century warming without inclusion
> of greenhouse gas forcing. Although solar and volcanic effects appear to
> dominate most of the slow climate variations within the past thousand
years,
> the impacts of greenhouse gases have dominated since the second half of the
> last century.
Have you ever wondered why all these solar papers go back to 1900? It's
because if there is a long-term trend it's too slow to explain the recent
warming. Global Warming really took off starting around 1980 while directly
measured solar irradiation oscillated very slightly for three sun spot
cycles.
Rich Blinne
Member ASA
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Received on Thu Feb 12 16:40:41 2009
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