Arctic Ice Holds Much CO2

scottie2shoes writes "The Edmonton Journal is reporting fascinating research on the role of arctic ice in absorbing carbon dioxide. It seems that (contrary to what was previously thought) arctic ice actually absorbs significant quantites of CO2 and is thus a key player in the 'greenhouse gas game'. So melting the ice caps won't just flood thousands of square miles of land and wipe out thousands of species, now it is is starting to sound serious..."

Comments

Re: Circular

[Black Parrot]

> So greenhouse gases cause global warming which melt the ice caps and then releases greenhouse gases?

Yep, positive feedback cycles are "circular".

Re:Circular

[Molina the Bofh]

In order to the ice melt, temperature must be increased. A hotter liquid can hold less dissolved gasses. An increase of one degree C on the oceans means some billions of tons of CO2 more on the air.

And we simply dump too much CO2. "The average American per capita emission is 5 tons of carbon annually."> (Damn! It's TOO much!)

More CO2 on the air, plus oceans retaining less C02 means something bad will happen.

Re:Buoyancy please....

[grozzie2]

don't forget that most of the world's fresh water is locked up in the Antarctic ice cap, and that isn't floating in the sea - it's on dry land

The greenland icecap is also on land, and it's on par with the antarctic icecap in terms of volume of ice. BUT, theres a big difference if it all melts. The greenland icecap is situated between a couple mountain ranges, and is in places more than 3 miles thick, with a bottom well below sea level. If it all melts, it becomes a huge lake, whereas if the antarctic cap melts, it runs down into the ocean.

Re:What we need...

[HalfFlat]

I thought the key issue with CO2 was that it did not have the same opacity to radiation at all frequencies. The basic scenario being as follows.

A range of solar radiation hits the Earth, a chunk of which is passed unimpeded by the CO2 in the atmosphere. This radiation hits the ground, water, whatever, gets bounced around a bit, absorbed and re-emitted preferentially at frequencies at which CO2 is more opaque. Thus CO2 in the atmosphere has a greater effect on decreasing the energy radiated part of the equation and less on the energy absorbed part.

If this picture is correct, a greater CO2 percentage in the atmosphere, other things being more or less equal, would lead to a higher steady state mean temperature.

PS: I'd wager most serious climatologists don't get a kick (or kickbacks) from scaring the population with the spectre of global warming. In fact, if you're looking for kickbacks, you're much more likely to find them on the other side of the fence. There is a real fear, backed by observed facts and admittedly primitive models, that the effect of mankind's activities on the environment will yield severe changes in climate in the not so distant future. Given how painful such changes would be, this ostritch approach towards the issue seems incredibly stupid.

Re:More Info?

[stevelinton]

Try http://books.nap.edu/html/climatechange/ (US National Academy of Sciences review).

The really detailed numbers are in http://www.grida.no/climate/ipcc_tar/ (which is about 1000 fairly technical pages. There are various summaries and the US report independently confirmed that they are reasonably accurate summaries,

Re:Circular

[Xilman]

Ok, a brief tutorial in planetology. Very brief and glosses over much that is presently known. Discovering more is left as an exercise.

While it's true that Venus is closer to the sun than we are, and Mars is further away, that's not the whole truth. Believe it or not, more solar radiation reaches the Earth's surface than ours. The albedo (i.e. reflectivity) of Venus is so high that most sunlight is reflected back out into space before it has a chance to heat the surface. In the case of the Earth, about 50% gets through and about 50% is reflected. The difference in distance between each planet and the sun is not enough to overcome this effect.

An important reason why Mars is so much colder than the Earth is not that it's further away but that it's also much less massive. The martian atmosphere may not be heated as strongly as the terrestial atmosphere, so the atoms and molecules may not move as fast, but they don't have to move as fast to escape and over the aeons they leak away. There are other factors involved, some of them caused or influenced by the lower mass, but this is one of them. Others include the lack of a strong magnetic field (to keep the solar wind at a good distance from heating the upper atmosphere) and, perhaps, the lack of active plate tectonics in recent history.

Turning to Venus, it rotates very slowly and does not have a pernament magnetic field. In its early history it probably had an atmosphere quite like the early Earth's and was very probably at much the same sort of temperature as on the Earth today, but just a bit warmer. Venus was still closer to the sun than was the Earth, but the Sun was noticeably cooler in those days (about 75-80 percent of present luminosity). Not having a magnetic field helped to heat the upper atmosphere; water was photolysed to hydrogen and oxygen and the hydrogen leaked away. At some point in its history, Venus got just a little bit too warm before life had evolved enough to start stabilising the climate as it has done here on Earth for the last few billion years. No-one got around to inventing photosynthesis in a big way to mop up carbon-dioxide and replace it with much less effective (as a greenhouse gas) oxygen while the lack of plate tectonics meant that organic matter and water wasn't safely swept ip into the upper mantle. At least one important feedback mechanism was missing on Venus and the greenhouse effect ran away until we see the conditions today: less solar heating at the surface than the Earth, but a temperature high enough to melt lead.

Paul