Scientific American - Arctic Sea Ice: What, Why, and What Next

[GliderGuider]

http://blogs.scientificamerican.com/guest-blog/2012/09/21/arctic-sea-ice-what-why-and-what-next/

Figure 3 - Arctic sea ice coverage, as reconstructed from 69 sites around the area, fluctuated in a fairly narrow range for more than 1400 years. In the last few decades, it has plunged abruptly.


Figure 6 - Artic sea ice volume has dropped far faster than coverage. In September the ice that remains is down by nearly 80% from its volume in 1980. At current pace of volume loss, the first ice-free Arctic day could come in just a few years.

This blogpost is the best compilation of the whole thing I've seen so far - a really monumental piece of work, accessible by everyone from interested amateur to professional denier...

[CRH]

1. Extrapolate the following paragraph, ...

Last edited Sat Sep 22, 2012, 03:59 PM - Edit history (1)

and the feedback loops present now would have to cease for 2030 to be realistic.

~~ snip from linked article

When we look at volume instead of area, we don’t see that half of all the ice has disappeared since 1980. Instead, we see that almost 80% of the September ice has disappeared in that time. And most of that loss has been in the last 12 years. 70% of the ice volume we saw in 2000 has disappeared. Less than one third of that ice volume – from just 12 years ago – is what we see today.

edit: added a word

[Speck Tater]

2. Something I didn't realize...

In June, the Arctic ice cap covers around 2% of the Earth’s surface – around 11 million square kilometers of Arctic ice cap out of a total of 510 million square kilometers of Earth’s land and oceans. And that 2% of the Earth’s surface, for a period of roughly two months, receives more solar energy per day than even the sunniest areas on the equator.

Analyzing this, Peter Wadhams of the Global Oceans Physics Program at Cambridge calculates that the loss of the Arctic ice throughout the summer would have a warming effect roughly equivalent to all human activity to date. That is to say, with the ice gone in summer, the planet would, have an additional heating effect, just as large as the heating effect of all human CO2 and other greenhouse gasses to date.

(My emphasis)

On edit: The punchline:

In other words, the complete meltdown of the Arctic could roughly double the rate of warming of the planet as a whole.

[longship]

3. DUers should read this.

R&K

[joshcryer]

4. Speaking of deniers, they think this is a good thing, I suspect.

After all one of their favorite go to talking points is "We were entering another ice age! Global warming is just keeping that from happening! It's a good thing!"

[AverageJoe90]

5. Sad but all too true. nt