Will the Ice Caps Melt?

American Thinker ^ | January 22, 2008 | Jerome J. Schmitt

[samtheman]

Yes. They will. Within 10 Billion years the sun will expand to be a red giant and melt the ice caps... And the rocks. That is a given.

I think you're too optimistic.

The Sun is expected to become a red giant in about 5.5 billion years

-- Red giant

[JRandomFreeper]

You could hunt Mastadons at the foot of a two mile high glacier, and while dining, be eaten leisurly by a local sabre toothed tiger!

That, and the expanding red giant star are good reasons to have out-of-town plans for that weekend... week... era... whatever.

/johnny

[JRandomFreeper]

It's within 10B years, and I'm booked from 2030 out.... I'll be ok. ;)

/johnny

[Right Wing Assault]

If the area of earth's surface is 5.1 x 10¹⁴ m², then the area of the oceans is about 3.6 x 10¹⁴ m² as he shows. If you have something with uniform thickness, the volume of it will be the area time the thickness. So, you multiply the area of the Earth's water surface, 3.6 x 10¹⁴ m², by the depth of the water predicted, 6 meters. This gives the volume of water needed: 6 x 10²⁴m³.

So, a similar volume of ice (actually about 10% more) must be melted to obtain that volume of water. He goes on to show how much heat is needed to melt that ice.

[ATOMIC_PUNK]

Will the Ice Caps Melt?

Yes in my Tanguray

[JasonC]

No, that line is just wrong.

The total mass of the earth is in fact 6 times 10 to the 24th kilograms.

But that figure is not required anywhere in the calculation.

Incidentally, the earth's density is about 4.5 times that of water...

The correct conclusion of the article is that the same operating new power term sufficient to heat the atmosphere 5C in 100 years, would need 30000 years to melt the ice caps.

Heat doesn't explicitly consider how much would be needed to heat up the oceans. But the mass of the oceans is 1.4 times 10 to the 21st kilograms - with a specific heat of 3850 J per degree per kg. This gives a figure close to this errant line - 5.4 times 10 to the 24th Joules of energy, would be required to raise the temperature of the entire ocean water mass by 1 degree C - and 2.7 times 10 to the 25th to raise it by 5C (all the way to the bottom).

In other words, the heat sink of the oceans themselves, has another 4 orders of magnitude, on the energy needed to melt the ice caps. Meaning oceans 5C hotter from top to bottom, are something with a time scale of tens of millions of years, if the operating power takes 100 years to heat the mere atmosphere.

The atmosphere is a rounding error in the stored latent heat of the ice caps. And the ice caps are a rounding error in the heat sink of the oceans themselves.

[kgdallen]

Since water and ice have approximately the same density, the volume of ice that needs to melt is (approximately) THE SAME as the volume of water needed to raise sea levels ~ 6m. Schmitt states this, so how come the volume of ice is about 8 ORDERS of magnitude Less than the volume of water???

[JasonC]

Except 3.6 x 10^14 * 6 is 2.16 * 10^15, not 6x10^24. The line has an extraneous figure from somewhere, probably mass of the earth, that is not involved in the remainder of the calculation. The 6x10^24 figure just has nothing to do with it.

[JRandomFreeper]

Because Ice Floats.

/johnny

[Right Wing Assault]

Oops, yes, I missed the incorrect exponent, too. It's 6 x 10¹⁴m³.

[kgdallen]

Yes, Ice floats. But Schmitt says “ volume of ice that must melt”. So, floating does not apply - it is melted!

[JRandomFreeper]

Since water and ice have approximately the same density

No, actually, that turns out to be not the case.

/johnny

[cogitator]

The thing is, it assumes a slow, linear rate of melting, i.e., viewing the ice sheets as a solid block of ice. They certainly are not that. My illustration is the breakup of the Larsen B ice shelf.

In January 2002, it appeared solid. In March 2002 it was splinters (not all of which have melted yet, obviously). The author of the posted piece would apparently take comfort in the fact that not all of that ice had melted even after the ice shelf was gone.

It's not just about melting. It's about the alteration of glacial and ice sheet dynamics caused by increased melting. Melt streams running down through more crevasses, lubricating the ice/bedrock interface. Warmer ocean temperatures eroding the underside of floating ice sheets. If a large chunk of ice breaks off an ice sheet and starts floating in the ocean, its going to melt a lot faster than if its still part of the main bulk of the ice sheet.

[kgdallen]

Schmitt in this article states” although ice floats, ice and water are very close in density”. So I am correct in saying water and ice have approximately the same density.

So why the (approximate) 8 orders of magnitude difference in volume of water and volume of ice. 10 to the 8th power is a huge difference

[upier]

That is the amount of water that needs to be dumped into the oceans from melting ice to raise the seas 20ft.

Another point missed is that if large quantities of South pole ice melts it allows the Antarctic land mass to rise. This is why the sea levels have been relatively constant for thousands of years.

[JRandomFreeper]

So, floating does not apply - it is melted

And, actually, yes, it does. Because melt water is fresh, and ocean water is saline, and melt-water rides on top of saline water.

You should spend some time working some provenance experiments. Just so you know that ice isn't the same density as water.

/johnny

[Redcloak]

Volume of water necessary to raise sea-level 20-feet: ~6 x 10²⁴m³

I don't understand where that number comes from, or does it mean anything?

It means that you would need an extra 6,000,000,000,000,000,000,000,000 cubic meters of water to cause sea level to rise 20'. Think of the Earth as a sphere of water with stuff sticking out of it over ~30% of its surface. Now imagine a sphere of water that's 40' wider in diameter. (20' each direction.) That larger sphere has a greater volume than the old sphere. The difference, less the dry bits sticking out, is ~6,000,000,000,000,000,000,000,000 cubic meters.

[JRandomFreeper]

So I am correct in saying water and ice have approximately the same density.

That turns out to not be compeletely accurate.

/johnny

[TigersEye]

So, a similar volume of ice (actually about 10% more) must be melted to obtain that volume of water. He goes on to show how much heat is needed to melt that ice.

In order to make the case doesn't the amount of ice on earth need to be established? Is there that much ice?

[Right Wing Assault]

No, actually, that turns out to be not the case.

Yes, it does, if you assume that 90% of something is approximately the same as 100%.