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Sunday, December 22, 2013

A Debate : This House believes that cosmic ray shower variations cause environmental perturbation and I speak against the motion


I was never much of a science student and the very first opportunity I had of dropping science( before it dropped me)  I did so . Having parted ways life cruised on and one never thought more of mundane things like Gravitation and Newton and particle physics et el. That is till the other day when the son called up from school. My first reaction was panic, as in ' what is the matter- something must be the matter' . Well, he reassured me that no, he hadn't been expelled, that he was hale and hearty and that the head mistress did not wish to see me but could I please write a debate for him- he had been chosen to represent school in this physics debate....Bravely I asked, 'So, what's the topic?'. He started to tell and then said,' I think mailing you might be a better idea'. My first reaction on reading the topic(cosmic ray shower variations cause environmental perturbation) was to laugh. Second was to tell the husband and the daughter ( they laughed) and third was to sit down and start reading up. I did manage to come up with something ( enough for the stipulated 3 minutes 30 seconds) , and am sharing this so that other parents , science challenged, may take heart and plough on.

The debate
Cosmic rays are very  high energy particles  mainly originating outside the Solar System.  Visible to the naked eye as the Seven Sisters, the Pleiades are the most famous of many surviving clusters of stars that formed together at the same time. The Pleiades were born during the time of the dinosaurs, and their supernova remnants generated cosmic rays.
 Members of the Jury, distinguished teachers and friends: the theory that cosmic ray shower variations cause environmental perturbation has been mooted by a cluster of climate scientists, primary among them being Henrik  Svensmark. Svensmark has calculated the variation in cosmic rays over the past 500 million years and come up with a paper titled “Evidence of nearby supernovae affecting life on Earth” .He  shows how the variable frequency of stellar explosions not far from our planet has ruled over the changing fortunes of living things throughout the past half billion years. He  has proposed that galactic cosmic rays (GCRs) could exert significant influence over global temperatures  and  that the solar magnetic field deflects GCRs, which are capable of seeding cloud formation on Earth.  So if the solar magnetic field were to increase, fewer GCRs would reach Earth, seeding fewer low-level clouds, which are strongly reflective.  Thus an increased solar magnetic field can indirectly decrease the Earth's albedo (reflectivity), causing the planet to warm 
 Svenmark’s work reminds me to remind you of this well known quote of Carl Sagan:
“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff. –in short Svensmark squarely apportions all variations at the doorstep of cosmic ray variations.
I contest the claim  that Cosmic ray showers cause environmental perturbation by the following arguments:
It has been noted by climate scientists actively publishing in the field that Svensmark has inconsistently altered data on most of his published work on the subject, an example being adjustment of cloud data that understates error in lower cloud data, but not in high cloud data.
Lief Svalgaard says that “the energetic GCR that ionize the lower atmosphere are only weakly influenced by variations in the geomagnetic field or by solar magnetic activity. Both cause low-altitude ionization rates to vary by (≈10%) in the course of a magnetic reversal or during a solar cycle. Over decades to millennia the GCR influx to the Solar System scarcely changes.”

Sun and Bradley  re-examined the surface-based cloud data and newer satellite data for an extended period but they also could not find any  meaningful relationship between cosmic ray intensity and cloud cover over tropical and extra-tropical land areas.

Kuang   showed that the variation in cloud optical thickness could easily be explained by the E1 Nino activity rather than variations in cosmic ray intensity.
The 2007 IPCC  report strongly attributes a major role in the ongoing global warming to human-produced gases such as carbon dioxide, nitrous oxide, and halocarbons.
In conclusion I would like to say to those  in favor of  the motion that this theory is like quoting the famous line from    2010: The Year We Make Contact: “My God, It’s full of stars.”
 For me ,  a megatheory as grand as this requires much more evaluation. I believe that  extraordinary claims demand extraordinary justification.
Thank you


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