Antarctic ice loss offsets warming: study

[Michaelangelica]

Antarctic ice loss offsets warming

A UK study has found that newly-exposed areas of Antarctic sea are now soaking up some of the carbon that causes global warming.

Scientists led by Professor Lloyd Peck of the British Antarctic Survey say that atmospheric and ocean carbon is being gobbled up by microscopic marine plants called phytoplankton, which float near the surface.

 

After absorbing the carbon through the natural process of photosynthesis, the phytoplankton are eaten, or die and sink to the ocean floor.

 

The phenomenon has been spotted in areas of open water exposed by the recent, rapid melting of several ice shelves - vast floating plaques of ice attached to the shore of the Antarctic peninsula.

 

Over the past 50 years, around 24,000 square kilometres of new open water have been created this way, and swathes of it are now colonised by phytoplankton, Peck's team reports in the journal, Global Change Biology.

. . .

. . . It shows nature's ability to thrive in the face of adversity.

 

"We need to factor this natural carbon absorption into our calculations and models to predict future climate change."

,. . .

 

Hardest hit

 

The Antarctic peninsula - the tongue of land that juts up towards South America - has been hit by greater warming than almost any other region on Earth.

 

In the past 50 years, temperatures there have risen by 2.5°C, around six times the global average.

 

Ice shelves are ledges of thick ice that float on the sea and are attached to the land. They are formed when ice is exuded from glaciers on the land.

 

In the past 20 years, Antarctica has lost seven ice shelves.

Antarctic ice loss offsets warming: study › News in Science (ABC Science)

[Zythryn]

Yes, this is a good example of negative feedback. Another is other areas that were too cold for plants to grow that now can grow, or grow faster (absorbing more CO2).

Unfortunately, I strongly suspect the negative feedback shown here is offset by other areas of the ecosphere that are no longer producing plants (the encroching deserts in China for example).

[Michaelangelica]

Yes, this is a good example of negative feedback. Another is other areas that were too cold for plants to grow that now can grow, or grow faster (absorbing more CO2).

Unfortunately, I strongly suspect the negative feedback shown here is offset by other areas of the ecosphere that are no longer producing plants (the encroching deserts in China for example).

Perhaps; to me it shows how complex predicting climate can be, and how complex is the WW system.

 

We know so little; and are like the proverbial "Bulls in a China Shop." With the Damoclean sword of a tipping point maybe somewhere around the next isle.

[Zythryn]

While the feedbacks are incredibly complicated, the result are pretty plain to see.

The basic science of which wavelengths CO2 is transparent to and which it will absorb are well documented.

Continued research is invaluable as we need to understand the whole cycle much better if we want a solution other than simply burning less carbon.

In the meantime, it would seem prudent to take advantage of the only solution we know will work.

[TheBigDog]

It is likely that there has been signifi cant anthropogenic

warming over the past 50 years averaged over each

continent except Antarctica (see Figure SPM.4).

The observed patterns of warming, including greater

warming over land than over the ocean, and their

changes over time, are only simulated by models that

include anthropogenic forcing. The ability of coupled

climate models to simulate the observed temperature

evolution on each of six continents provides stronger

evidence of human infl uence on climate than was

available in the TAR. {3.2, 9.4}

The Antarctic peninsula - the tongue of land that juts up towards South America - has been hit by greater warming than almost any other region on Earth.

 

In the past 50 years, temperatures there have risen by 2.5°C, around six times the global average.

Are these quotes compatible?

 

Bill

[Zythryn]

Compatible yes, they could be, although they are not supportive of each other.

The IPCC statement may have simply said all continents besides antartica because their statement was about all continents besides antartica. They may simply have not had the level of data collection about the antartic, thus they left it out.

Please note, I am not saying this is the case, I would need to read more of the IPCC statement to come to that conclusion. I am simply responding to your question about if the two quotes are compatible.

[TheBigDog]

Compatible yes, they could be, although they are not supportive of each other.

The IPCC statement may have simply said all continents besides antartica because their statement was about all continents besides antartica. They may simply have not had the level of data collection about the antartic, thus they left it out.

Please note, I am not saying this is the case, I would need to read more of the IPCC statement to come to that conclusion. I am simply responding to your question about if the two quotes are compatible.

No problem, Zyth. The quote is from the summary for executives. I am digging through the full document to find out more about Antarctica from the IPCC AR4.

 

Bill

[TheBigDog]

In the SH, where the ozone hole has played a

role, it has resulted in cooling over 1971 to 2000 for parts of

the interior of Antarctica but large warming in the Antarctic

Peninsula region and Patagonia. Temperatures generally have

risen more than average where fl ow has become more poleward,

and less than average or even cooled where fl ow has become

more equatorward, refl ecting the PDO and other patterns of

variability.

It appears that there is agreement, I just needed to dig for the details.

 

Bill

[Michaelangelica]

Sea Ice Measurements Database - Australian Antarctic Data Centre

 

Main page - Australian Antarctic Data Centre

 

A lot of the continent is not covered by measuring instruments, so our knowledge gaps are large.

Rising tide of interest in sea level rise - Australian Antarctic Division

 

The oceans south of 40°S contain roughly 40% of the global oceanic inventory of CO2 and a small change in this can have a significant effect on atmospheric CO2.

 

Research will address the role of the Southern Ocean in the global carbon cycle and also other biogeochemical cycles.

Ice, Ocean, Atmosphere and Climate - program overview - Australian Antarctic Division