2011-06-22 08:39:11Atmospheric Carbon Dioxide Buildup Unlikely to Spark Abrupt Climate Change, Scientists Find
John Cook

john@skepticalscience...
121.222.9.229

Can easily see this result being taken out of context...

http://www.sciencedaily.com/releases/2011/06/110620094555.htm

There have been instances in Earth history when average temperatures have changed rapidly, as much as 10 degrees Celsius (18 degrees Fahrenheit) over a few decades, and some have speculated the same could happen again as the atmosphere becomes overloaded with carbon dioxide.

New research lends support to evidence from numerous recent studies that suggest abrupt climate change appears to be the result of alterations in ocean circulation uniquely associated with ice ages.

"There might be other mechanisms by which greenhouse gases may cause an abrupt climate change, but we know of no such mechanism from the geological record," said David Battisti, a University of Washington atmospheric sciences professor.

Battisti was part of a team that used a numerical climate model coupled with an oxygen-isotope model to determine what caused climate shifts in a computer-generated episode that mimicked Heinrich events during the last ice age, from 110,000 to 10,000 years ago. Heinrich events produced huge numbers of North Atlantic Ocean icebergs that had broken off from glaciers.

The simulations showed the sudden increase in North Atlantic sea ice cooled the Northern Hemisphere, including the surface of the Indian Ocean, which reduced rainfall over India and weakened the Indian monsoon.

Battisti noted that while carbon dioxide-induced climate change is unlikely to be abrupt, the impacts of changing climate could be.

"When you lose a keystone species, ecosystems can change very rapidly," he said. "Smoothly retreating sea ice will cause fast warming if you live within a thousand kilometers of the ice. If warming slowly dries already semi-arid places, fires are going to be more likely."

Previous studies of carbonate deposits from caves in China and India are believed to show the intensity of monsoon precipitation through the ratio of specific oxygen isotopes. The modeling the scientists' used in the current study reproduced those isotope ratios, and they determined that the Heinrich events were associated with changes in the intensity of monsoon rainfall in India rather than East Asia.

The research is published online June 19 by Nature Geoscience. The lead author is Franceso Pausata of the Bjerknes Centre for Climate Research in Norway. Besides Battisti, other co-authors are Kerim Nisancioglu of UNI Research in Norway and Cecilia Bitz of the UW.

2011-06-22 09:22:24
nealjking

nealjking@gmail...
84.151.55.191

I actually don't get a clear message from this at all.

2011-06-22 09:24:22
Rob Honeycutt

robhon@mac...
98.207.62.223

I had a brief email exchange with Battisti on this...

 

On Jun 20, 2011, at 3:38 PM, Rob Honeycutt wrote:

Dr Battisti,
I just finished reading an article in the Science Daily where you are quoted.  http://www.sciencedaily.com/releases/2011/06/110620094555.htm
The opening sentence of the article doesn't jibe with my own understanding of climate.  It states, "There have been instances in Earth history when average temperatures have changed rapidly, as much as 10 degrees Celsius (18 degrees Fahrenheit) over a few decades, and some have speculated the same could happen again as the atmosphere becomes overloaded with carbon dioxide."
The article then goes on to quote you regarding Heinrich events and abrupt climate change.  Am I incorrect in my thinking that Heinrich events are like D-O events that are representative of a bi-polar sea saw where you might have rapid warming in the Arctic but an antiphased cooling event in the Antarctic?  In other words, while the climate of a region might warm 10C over the course of a few decades, that is not representative of the entire planet.  Is the wording of that opening sentence incorrect or am I looking at this wrong?

Best regards,

Rob Honeycutt

Hi Rob, 

   The sentence is a bit vague in what is mean by averaged temperature. As you can see from the figure in our paper (or in any other paper that looked at the climate impact of a large change in sea ice in the north atlantic), the temperature changes are largest in the north atlantic, with large temperature changes across a large portion of the northern hemisphere high latitudes. Since the signal is mainly a winter phenomenon, the winter changes can be locally very large (> 20C). No modeling or observational study -- including ours -- has reported any temperature change of consequence  in the southern hemisphere associated with Dansgaard Oeschger events or Heinrich events. The bipolar sea saw refers to a very weak temperature response in the southern ocean associated with ocean circulation changes that that is seen in some (but not all) of the heinrich events, and in none of the Dansgaard Oeschger events. Furthermore, DO and Heinrich events have never been convincingly seen in any proxy climate (as opposed to ocean) record between 15S and the southern ocean.  
  I hope this helps. 
Cheers, David

Professor of Atmospheric Sciences
   and Tamaki Endowed Chair
Dept of Atmospheric Sciences
University of Washington 351640
Seattle WA 98195-1640
phone: 206 543 2019       fax: 206 543 0308

2011-06-22 09:27:11
Rob Honeycutt

robhon@mac...
98.207.62.223

Really?  D-O events have NO corresponding cooling in the southern hemisphere?

This exchange was literally from last night and I haven't responded.  If anyone has any insights that they'd like me to pass along please let me know.

2011-06-22 12:01:27
nealjking

nealjking@gmail...
84.151.55.191

"The simulations showed the sudden increase in North Atlantic sea ice cooled the Northern Hemisphere, including the surface of the Indian Ocean, which reduced rainfall over India and weakened the Indian monsoon.

Battisti noted that while carbon dioxide-induced climate change is unlikely to be abrupt, the impacts of changing climate could be.

"When you lose a keystone species, ecosystems can change very rapidly," he said. "Smoothly retreating sea ice will cause fast warming if you live within a thousand kilometers of the ice. If warming slowly dries already semi-arid places, fires are going to be more likely." "

 

What I'm not getting here:

- CO2-induced climate change won't be abrupt; but

- impacts of climate change will be.

 

Is that like sitting in a swimming pool, and the water level slowly rises; but I suddenly drown 3 minutes after the water level reaches my nose? Or what?

2011-06-22 18:54:15car analogy (though I don't like to use those)
jyyh
Otto Lehikoinen
otanle@hotmail...
85.78.241.106

Maybe an analogy with car engines would be appropriate here, I think what they're saying is effect of CO2 is like the freely breathing normal engine, but add enough pressure (more CO2 in the analogy) to the intake the engine will become turbo/supercharged (the abrupt effects of other forcings). And the mankind is driving a car (the climate) with a supercharger that is set to go off at an unknown pressure (the uncertainty in the climate models WRT abrupt climate change). But I'm of the same opinion this result is very easily converted to 'no reason to worry, the supercharger won't go off in the next bend (with the famous cliff).

2011-06-22 23:49:15Up, up, and away!
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

How about a hot-air ballon analogy?

2011-06-23 01:48:41
Rob Honeycutt

robhon@mac...
98.207.62.223

Battisti admits the opening sentence is vague but he really doesn't clarify anything for me at all.  

I almost interpret what he's saying is, "Watch out because it ain't gonna be the steady rise in temp from CO2 that's gonna get us.  It's going to be an alteration in ocean circulation that eventually pops up to bite us in the a**."

The problem is that it's a complex issue where the wording of the title and the opening sentence tend to lead the reader to the exact opposite conclusion.  That CO2 doesn't drive rapid climate change.

2011-06-23 07:41:41
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.103.217

Yup, clear as mud. I took the piece as saying abrupt change may occur regionally or locally, rather than on a global scale. Hence the comment about marked cooling in the northern hemisphere, but no cooling in the southern hemisphere. Given the inter-connectdness of some systems, that's not a statement that will universally hold true.   

2011-06-24 01:53:45Denier Drone Posting
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

The following was posted a few minutes ago on the comment thread to Climate Change: Public Skeptical, Scientists Sure

Joseph Neubauer (jbn1) wrote:

"New research lends support to recent studies that suggest abrupt climate change is the result of alterations in ocean circulation uniquely associated with ice ages, not from atmospheric carbon dioxide."

The source of this quote is:

Atmospheric Carbon Dioxide Buildup Unlikely to Spark Abrupt Climate Change

Released: 6/20/2011 8:00 AM EDT
Source: University of Washington

Newswise — There have been instances in Earth history when average temperatures have changed rapidly, as much as 10 degrees Celsius (18 degrees Fahrenheit) over a few decades, and some have speculated the same could happen again as the atmosphere becomes overloaded with carbon dioxide.

New research lends support to evidence from numerous recent studies that suggest abrupt climate change appears to be the result of alterations in ocean circulation uniquely associated with ice ages.

“There might be other mechanisms by which greenhouse gases may cause an abrupt climate change, but we know of no such mechanism from the geological record,” said David Battisti, a University of Washington atmospheric sciences professor.

Battisti was part of a team that used a numerical climate model coupled with an oxygen-isotope model to determine what caused climate shifts in a computer-generated episode that mimicked Heinrich events during the last ice age, from 110,000 to 10,000 years ago. Heinrich events produced huge numbers of North Atlantic Ocean icebergs that had broken off from glaciers.

The simulations showed the sudden increase in North Atlantic sea ice cooled the Northern Hemisphere, including the surface of the Indian Ocean, which reduced rainfall over India and weakened the Indian monsoon.

Battisti noted that while carbon dioxide-induced climate change is unlikely to be abrupt, the impacts of changing climate could be.

“When you lose a keystone species, ecosystems can change very rapidly,” he said. “Smoothly retreating sea ice will cause fast warming if you live within a thousand kilometers of the ice. If warming slowly dries already semi-arid places, fires are going to be more likely.”

Previous studies of carbonate deposits from caves in China and India are believed to show the intensity of monsoon precipitation through the ratio of specific oxygen isotopes. The modeling the scientists’ used in the current study reproduced those isotope ratios, and they determined that the Heinrich events were associated with changes in the intensity of monsoon rainfall in India rather than East Asia.

The research is published online June 19 by Nature Geoscience. The lead author is Franceso Pausata of the Bjerknes Centre for Climate Research in Norway. Besides Battisti, other co-authors are Kerim Nisancioglu of UNI Research in Norway and Cecilia Bitz of the UW.

The work was funded by the Norwegian Research Council and the U.S. National Science Foundation.

 

2011-06-24 03:18:11
nealjking

nealjking@gmail...
84.151.62.211

Maybe it would be a good idea to develop a set of simple questions that clarify what he means, and submit them to him. Then post the q&a on SkS and promote it. Battisti really seems to have no idea of what he's encouraging.

2011-06-25 00:24:24PlanetSave's take on this story...
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Carbon Dioxide Unlikely to Spark Abrupt Climate Change

By Joshua S. Hill, PlanetSave, June 24, 2011

New research into the issue of whether atmospheric carbon dioxide has the capacity to spark an abrupt climate change has shown that past changes are more likely linked to alterations in ocean circulation unique associated with ice ages, rather than a catastrophic level of atmospheric carbon dioxide.

“There might be other mechanisms by which greenhouse gases may cause an abrupt climate change, but we know of no such mechanism from the geological record,” said David Battisti, a University of Washington atmospheric sciences professor.

The important aspect of this study to understand, however, is not that carbon dioxide cannot play a role in climate change, but rather that it is unlikely to be the cause for an abrupt shift in the climate.

David Battisti was part of a team of researchers which created a numerical climate model coupled together with an oxygen-isotope model to determine what caused climate shifts in a computer-generated episode that mimicked Heinrich events during the last ice age, which occurred from 110,000 to 10,000 years ago.

According to Wikipedia, a Heinrich event is an event when “armadas of icebergs broke off from glaciers and traversed the North Atlantic.”

The simulations showed that the sudden increase of sea-ice into the North Atlantic was directly linked to cooling of the Northern Hemisphere, and cooling of the surface of the Indian Ocean which in turn weakened the Indian monsoon and reduced rainfall over India.

Battisti makes it clear that while climate changes induced by carbon dioxide are unlikely to be abrupt, its affect is still catastrophically important.

“When you lose a keystone species, ecosystems can change very rapidly,” he said. “Smoothly retreating sea ice will cause fast warming if you live within a thousand kilometers of the ice. If warming slowly dries already semi-arid places, fires are going to be more likely.”

Source: Washington University

Source: Planetsave (http://s.tt/12IGL)

 

2011-06-25 00:53:27
nealjking

nealjking@gmail...
84.151.51.94

OK, I think I have a bit more perspective on it:

- On the one hand, increasing CO2 is not going to generate a dramatically sudden climate change (mechanism: effect on ocean circulation, blah blah); but

- On the other hand, environmental changes due to climate change can be dramatic, because when a slow change hits a threshold, the inter-species dynamics can switch quickly. (Example: When the winter temperature in the pine forests of North America eventually rises above the killing point for beetles, the beetles start to destroy the forest outright.)

- So if we keep our eyes on the thermometers, we will see a gradual change; but if we watch out for consequences, we might experience a roller-coaster ride.

The article is an excellent example of poor communication: It buries the big picture in details that break the "momentum" of the meaning.

2011-06-25 01:44:49nealjking
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

Which article are you referring to in your prior post?

2011-06-25 01:51:02Tipping Points -- An SkS Void???
John Hartz
John Hartz
john.hartz@hotmail...
98.122.98.161

The SkS search engine generates only seven articles when "tipping points" is keyed into it. 

None of the seven articles comprehensively addresses this issue. 

Do we have a "void" to be filled?


OPs! I meant to post this as a new blog. Will do so now. 

2011-06-25 05:19:10
nealjking

nealjking@gmail...
84.151.51.94

The original article, that JC thought might be taken "out of context".

Indeed, it's hard to figure out what context to put it in.