Rare clouds over Antarctica suggest global warming

[cal04]

Scientists say the appearance of rare clouds over Antarctica could be an indicator of global warming.

Dr Andrew Klekociuk from the Australian Antarctic Division says nacreous clouds are naturally-occurring, and indicate extremely cold temperatures in the stratosphere.

The stratosphere is between eight and 50 kilometres above the earth's surface, and gets colder as temperatures closer to earth get warmer.

Dr Klekociuk says as global warming increases, temperatures in the stratosphere should drop, and that has been reflected in data collected over the last 25 years.

more
http://www.abc.net.au/news/newsitems/200608/s1702788.htm

[amitten]

1. So what fresh hell is this now?

Is the colder stratosphere going to kill us all that much faster now, or what?

Or, should I be happy about this?

Christ, this global warming crap is making me freakin' nuts.

WHO IS DOING SOMETHING ABOUT ALL THIS?

And don't tell me to buy new freaking energy-saving light bulbs because that is NOT going to cut it!!!

[lapfog_1]

2. Yup... we don't have 25 years to solve this

We need to switch to non greenhouse fuels, both for vehicles and for power plants.

We need to plants just a whole bunch of trees. And we need to try the ground up granite experiment on our existing forests.

We need to immediately stop cutting down the Amazon forest and start cloud seeding there to end the drought.

We need to look at ways to actively cool the planet (but let's not leap into this until we have studied it just a bit).

We need to control the population of humans on this planet, with an eye toward reducing the planet population by 3/4 (so that all who live may enjoy a modern life).

We don't have a lot of time to do all these things... maybe only 5 years, maybe 10.

Otherwise there will be widespread famine and much more of resource wars... And we will involuntarily reduce the population by 10 fold. Or worse.

[hatrack]

3. One of the reasons the ozone layer's still in trouble - these temps

With heat held lower in the troposphere, there's less energy reradiating to space, meaning that the stratosphere and mesosphere are continuing to cool.

Along with the chlorine molecules carried aloft by CFC molecules, the other key factor is temperature - the lower the temps, the more ozone molecules can be destroyed.

[jpak]

4. That, and anthropogenic methane emissions

Methane is the principal source of water vapor in the stratosphere (it's oxidized to water and CO2).

Nacreous clouds (AKA polar stratospheric clouds, PSC) play a central role in the reactions that destroy stratospheric ozone in the Antarctic. They form at temperatures <80 degrees C.

And ozone is the principal greenhouse gas that warms the stratosphere...destroy ozone and the stratosphere cools.

So...more methane > more stratospheric water vapor > more PSCs > more ozone destruction > cooler temps > more PSCs...etc.

It's a positive feedback.

[XemaSab]

6. Is that because the unstable

ozone-destroying molecules don't break down as fast? :shrug:

[CHIMO]

5. Scientists worried by rare cloud formation over Antarctica

HOBART, AUSTRALIA — Some of the coldest temperatures on Earth have fostered a rare cloud formation over Australia's Mawson station in Antarctica, scientists said Tuesday.

Meteorological officer Renae Baker captured spectacular images of the nacreous clouds, also known as polar stratospheric clouds, on July 25.

The clouds only occur at high polar latitudes in winter, requiring temperatures less than approximately minus 80 C. A weather balloon measured temperatures down to minus 87 C on the day the photos were taken.

“Amazingly, the winds at this height were blowing at nearly 230 kilometres per hour,” Ms. Baker said on the Australian government's Antarctic Division's website.

http://www.theglobeandmail.com/servlet/story/RTGAM.20060801.wclouds0801/BNStory/Science/home



A rare and spectacular nacreous cloud (top) appears high in the stratosphere about 20 kilometres above Australia's Mawson station in Antartica. (Renae Baker/AFP/Getty Images)