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Name: Bill
Status: other
Location: Outside U.S.
Country: New Zealand
Date: N/A 

I notice that the ice cover has been slightly above normal for the Southern hemisphere and below normal for the Northern hemisphere for the last few years. To what extent does the 3% closer approach to the Sun in the slightly distorted orbit of the Earth around the Sun affect this? ie 7 July 2010 the Earth was furthest away from the Sun corresponding to Southern hemisphere winter and Northern Hemisphere Summer. Surely the close approach coming up would be expected to shorten the Northern Hemisphere winter and make the Southern Hemisphere warmer in their summer.

Attributing the "average" temperature of any point on Earth's surface to the Earth / Solar distance involves a giant leap of faith. There are many factors that come into play determining Earth's temperature. Solar distance is only one, and possibly not even the most important factor. For example, "At what altitude is the temperature measured?" Is the temperature measured "at night" or "during the day"? What part does precipitation play? The list of possibly confounding factors is long, and complicate one another. What role does Solar activity play on a given day / week / or month? A "simple cause and effect" on any particular relationship is risky, at best, and likely misleading.

Vince Calder

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