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Are days getting longer because of global warming?

The ice that melts in Antarctica and in Greenland as a result of global warming will redistribute into the oceans of the world.  This will involve redistribution of many gigatonnes of mass from the polar regions (close to the earth's axis) to the average latitude of the earth's oceans (further from the earth's axis). This means that to conserve angular momentum the earth should reduce its spin rate.  Has this occurred and if so what is the magnitude of the effect; A - Now - and B - when all the polar ice has melted?

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Categories: Planet Earth.

Tags: globalwarming, Icecaps, melting, Daylength.

 

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fomotats says:

No ... days get warmer or colder, drier or wetter, depending on where on earth you are.

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Tags: globalwarming, Icecaps, melting, Daylength.

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posted on 2011-04-05 06:12:06 | Report abuse


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avpr212 says:

No. The day is measured by 24 hours, i.e. 7.94243385x10^14  periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of cesium 133. Since this period of time will not be affected by the climate of the earth, the day will not get longer.

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Tags: globalwarming, Icecaps, melting, Daylength, cesium.

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posted on 2011-04-15 14:00:36 | Report abuse


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Pedant says:

The answer is yes. The predicted maximum sea level rise this century is around 1 metre with about half due to thermal expansion and half due to melting of land based ice. This implies a 1 metre increase in the Earth's radius which amounts to about 1 part in 6 million.

Moment of inertia is proportional to the square of radius so, to conserve angular momentum, we could expect the Earth's rotation to slow down by about 1 part in 3 million. Taking into account the Earth's mean density of 5.5, this effect would be reduced to about 1 part in 16.5 million. This amounts to about 5 milliseconds per day or about 2 seconds per year.

The effect seems to me to be somewhat larger than expected. I'd be grateful if someone would point out where I've gone wrong!

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Tags: globalwarming, Icecaps, melting, Daylength.

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posted on 2011-04-28 12:12:09 | Report abuse

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petethebloke says:

Pedant, your sums seem OK, but I wonder if you could confirm these parts of your calculation:

  1. A rise of 1m this century sounds huge. I'm sure most figures I've seen are a few tens of centimetres.
  2. Surely a sea-level rise of 1m does not equal an increase in radius of 1m if half of this rise is a result of melting land-based ice? After all, the ice in the Himalayas, say, would now be water nearer to the earth's centre.
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Tags: globalwarming, Icecaps, melting, Daylength.

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posted on 2011-05-03 20:44:08 | Report abuse


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