[geo] Re: we're engineering the arctic now
I registered for Dot Earth, but for some reason, the message on this particular one won't allow me to log in. So I ask for you to post it if you wish. Without human interference, the interglacial would still take at least several thousand years to end and the ice sheets to return to cover the northern hemisphere. With it, the interglacial continues. Most likely, the CO2 we have added to the atmosphere will have been removed by some form of air capture in 100-200 years (sorry to disappoint David Archer et al.). Thus, we will have had no impact on preventing the return of the Laurentide Ice Sheet and related ones in Europe and Asia. UNLESS we take the lessons learned from our inadvertent intervention into the climate system and use it to our benefit. One of the definitions of geoengineering that is often used is that of deliberate modification of Earth's environment on a large scale to suit human needs and promote habitability. The needs of the present are to stop the effects of global warming before the planet becomes uninhabitable for humans. Geoengineering in this instance is the use of technologies that stop global warming without reducing emissions of CO2 and other greenhouse gases. But once we can can control the CO2 level in the atmosphere, do we really want it to return to the pre-industrial level? Probably so. That was the level that allowed a stable climate and for human civilization to develop. At some point, probably thousands of years from now, we will want to counteract the natural cycle and prevent the interglacial from ending. By then, we will have developed far more advanced technologies of all types than today and adjusting the climate will be relatively simple. Assuming we survive our current experience with global warming, we will be able to build on it and develop the technologies to modify climate to our needs, back to the first definition. Not surprisingly, there are those on the environmental left who would welcome the return of the ice sheets. One poster at the geoengineering group even said he thought we should allow the ice sheets to cover Canada and the northern U.S. again because the glaciers would scrape up more minerals that could be used. Like we are expecting a shortage of iron and nickel in 8000 AD? He then went on to imagine that the survivors (NY Times won't be able to publish under 2 miles of ice, sorry Andy, must change name of blog to Dot Ice) could all go and live in the tropics, where, of course, food will still be limited due to changes in precipitation and in the subtropics, winds will howl most of the time. The ice age was no picnic, even in the southern U.S. How people come to view humans, their own species as the enemy beats me. We've made some mistakes and they have cost us and other species. But at least we are on the path to the 12 step recovery program by recognizing we have a problem. Is the answer to alcoholism to shoot all the drunks? An even more extreme view shared by many, but voiced by few (for understandable reasons) is that humans are an invasive species that should be eliminated from the planet! Moi kudzu? Do I look like a zebra mussel to you? For this select crowd, I have come up with a suitable name. Cutterites. After the character in the BBC TV series Primeval, Helen Cutter, who became such a misanthrope she went back in time and tried to eliminate all the early humans. I'm sure Helen would not be in favor of continuing the interglacial either. And what happened to her experiment in preventative extinction? She was crushed by a dinosaur that followed her through one of her time portals. Gotta watch out for that technology. It'll get you when you least expect it. Alvia Gaskill Pro-Human Lobbyist - Original Message - From: Andrew Revkin anr...@nytimes.com To: geoengineering@googlegroups.com Sent: Thursday, September 03, 2009 3:40 PM Subject: [geo] we're engineering the arctic now http://www.nytimes.com/2009/09/04/science/earth/04arctic.html http://dotearth.blogs.nytimes.com/2009/09/03/humans-may-have-ended-long-arctic-chill/ we may be able to 'skip' the next ice age in fact. would love your thoughts in the comments section. -- Andrew C. Revkin The New York Times / Environment 620 Eighth Ave., NY, NY 10018 Tel: 212-556-7326 Mob: 914-441-5556 Fax: 509-357-0965 http://www.nytimes.com/revkin --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: we're engineering the arctic now
Alvia: I too have been cut out of the Dot Earth comments and I have been contributing for a few years. Andy asked me to e-mail him directly and I expect I will have to start doing that if he is careful to suppress my full name, but whoever is screening appears to be anti Geoengineering. You missed one key point. All the climate variations are superimposed on top of an upward trend heading to 25 C even without CO2 increase. As you know this has happened at least 5 times during the 540 million year history of the Earth and is probably related to plate or land mass motion and how it influences ocean currents. No matter what they think about the dangers or risks (pretty stupid to think it would be implemented without risk assessment) geo will prove to be essential to block the increase. It is not going to be either or. -gene -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Alvia Gaskill Sent: Friday, September 04, 2009 7:06 AM To: anr...@nytimes.com; geoengineering@googlegroups.com Subject: [geo] Re: we're engineering the arctic now I registered for Dot Earth, but for some reason, the message on this particular one won't allow me to log in. So I ask for you to post it if you wish. Without human interference, the interglacial would still take at least several thousand years to end and the ice sheets to return to cover the northern hemisphere. With it, the interglacial continues. Most likely, the CO2 we have added to the atmosphere will have been removed by some form of air capture in 100-200 years (sorry to disappoint David Archer et al.). Thus, we will have had no impact on preventing the return of the Laurentide Ice Sheet and related ones in Europe and Asia. UNLESS we take the lessons learned from our inadvertent intervention into the climate system and use it to our benefit. One of the definitions of geoengineering that is often used is that of deliberate modification of Earth's environment on a large scale to suit human needs and promote habitability. The needs of the present are to stop the effects of global warming before the planet becomes uninhabitable for humans. Geoengineering in this instance is the use of technologies that stop global warming without reducing emissions of CO2 and other greenhouse gases. But once we can can control the CO2 level in the atmosphere, do we really want it to return to the pre-industrial level? Probably so. That was the level that allowed a stable climate and for human civilization to develop. At some point, probably thousands of years from now, we will want to counteract the natural cycle and prevent the interglacial from ending. By then, we will have developed far more advanced technologies of all types than today and adjusting the climate will be relatively simple. Assuming we survive our current experience with global warming, we will be able to build on it and develop the technologies to modify climate to our needs, back to the first definition. Not surprisingly, there are those on the environmental left who would welcome the return of the ice sheets. One poster at the geoengineering group even said he thought we should allow the ice sheets to cover Canada and the northern U.S. again because the glaciers would scrape up more minerals that could be used. Like we are expecting a shortage of iron and nickel in 8000 AD? He then went on to imagine that the survivors (NY Times won't be able to publish under 2 miles of ice, sorry Andy, must change name of blog to Dot Ice) could all go and live in the tropics, where, of course, food will still be limited due to changes in precipitation and in the subtropics, winds will howl most of the time. The ice age was no picnic, even in the southern U.S. How people come to view humans, their own species as the enemy beats me. We've made some mistakes and they have cost us and other species. But at least we are on the path to the 12 step recovery program by recognizing we have a problem. Is the answer to alcoholism to shoot all the drunks? An even more extreme view shared by many, but voiced by few (for understandable reasons) is that humans are an invasive species that should be eliminated from the planet! Moi kudzu? Do I look like a zebra mussel to you? For this select crowd, I have come up with a suitable name. Cutterites. After the character in the BBC TV series Primeval, Helen Cutter, who became such a misanthrope she went back in time and tried to eliminate all the early humans. I'm sure Helen would not be in favor of continuing the interglacial either. And what happened to her experiment in preventative extinction? She was crushed by a dinosaur that followed her through one of her time portals. Gotta watch out for that technology. It'll get you when you least expect it. Alvia Gaskill Pro-Human Lobbyist - Original Message - From: Andrew Revkin anr...@nytimes.com
[geo] Re: we're engineering the arctic now
Apologies to those who are not Dot Earth readers (and I *do* encourage everyone to have a look)... But just to make it clear to all, I do 98 percent of the comment moderation on the blog (no easy task) and there is NO screening or censorship (to the consternation of some, who feel the blog has been taken over by climate skeptics). If a comment is on topic and constructive and polite, it gets published. There *have* been significant technical glitches with a transition to a new comment mechanism, so many comments have been lost (by folks of all stripes). I always recommend keeping a copy of text instead of writing the comment in the submission box. Then it can be emailed to me as a backstop. At 8:54 AM -0400 9/4/09, Eugene I. Gordon wrote: Alvia: I too have been cut out of the Dot Earth comments and I have been contributing for a few years. Andy asked me to e-mail him directly and I expect I will have to start doing that if he is careful to suppress my full name, but whoever is screening appears to be anti Geoengineering. You missed one key point. All the climate variations are superimposed on top of an upward trend heading to 25 C even without CO2 increase. As you know this has happened at least 5 times during the 540 million year history of the Earth and is probably related to plate or land mass motion and how it influences ocean currents. No matter what they think about the dangers or risks (pretty stupid to think it would be implemented without risk assessment) geo will prove to be essential to block the increase. It is not going to be either or. -gene -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Alvia Gaskill Sent: Friday, September 04, 2009 7:06 AM To: anr...@nytimes.com; geoengineering@googlegroups.com Subject: [geo] Re: we're engineering the arctic now I registered for Dot Earth, but for some reason, the message on this particular one won't allow me to log in. So I ask for you to post it if you wish. Without human interference, the interglacial would still take at least several thousand years to end and the ice sheets to return to cover the northern hemisphere. With it, the interglacial continues. Most likely, the CO2 we have added to the atmosphere will have been removed by some form of air capture in 100-200 years (sorry to disappoint David Archer et al.). Thus, we will have had no impact on preventing the return of the Laurentide Ice Sheet and related ones in Europe and Asia. UNLESS we take the lessons learned from our inadvertent intervention into the climate system and use it to our benefit. One of the definitions of geoengineering that is often used is that of deliberate modification of Earth's environment on a large scale to suit human needs and promote habitability. The needs of the present are to stop the effects of global warming before the planet becomes uninhabitable for humans. Geoengineering in this instance is the use of technologies that stop global warming without reducing emissions of CO2 and other greenhouse gases. But once we can can control the CO2 level in the atmosphere, do we really want it to return to the pre-industrial level? Probably so. That was the level that allowed a stable climate and for human civilization to develop. At some point, probably thousands of years from now, we will want to counteract the natural cycle and prevent the interglacial from ending. By then, we will have developed far more advanced technologies of all types than today and adjusting the climate will be relatively simple. Assuming we survive our current experience with global warming, we will be able to build on it and develop the technologies to modify climate to our needs, back to the first definition. Not surprisingly, there are those on the environmental left who would welcome the return of the ice sheets. One poster at the geoengineering group even said he thought we should allow the ice sheets to cover Canada and the northern U.S. again because the glaciers would scrape up more minerals that could be used. Like we are expecting a shortage of iron and nickel in 8000 AD? He then went on to imagine that the survivors (NY Times won't be able to publish under 2 miles of ice, sorry Andy, must change name of blog to Dot Ice) could all go and live in the tropics, where, of course, food will still be limited due to changes in precipitation and in the subtropics, winds will howl most of the time. The ice age was no picnic, even in the southern U.S. How people come to view humans, their own species as the enemy beats me. We've made some mistakes and they have cost us and other species. But at least we are on the path to the 12 step recovery program by recognizing we have a problem. Is the answer to alcoholism to shoot all the drunks? An even more extreme view shared by many, but voiced by few (for understandable reasons) is that humans are an invasive species that should
[geo] Re: we're engineering the arctic now
Web sites are like airports. They always seem to be under construction whenever I pass through. I totally failed to find a way to post a comment and don't know what dot earth is So I e-mailed my comment direct to Andy - not sure if he has yet had time to post it but, for info the geoengineering list, it is appended further below Peter - Original Message - From: Andrew Revkin anr...@nytimes.com To: Eugene I. Gordon euggor...@comcast.net; agask...@nc.rr.com; geoengineering@googlegroups.com Sent: Saturday, September 05, 2009 1:59 AM Subject: [geo] Re: we're engineering the arctic now Apologies to those who are not Dot Earth readers (and I *do* encourage everyone to have a look)... But just to make it clear to all, I do 98 percent of the comment moderation on the blog (no easy task) and there is NO screening or censorship (to the consternation of some, who feel the blog has been taken over by climate skeptics). If a comment is on topic and constructive and polite, it gets published. There *have* been significant technical glitches with a transition to a new comment mechanism, so many comments have been lost (by folks of all stripes). I always recommend keeping a copy of text instead of writing the comment in the submission box. Then it can be emailed to me as a backstop. Hi Andy Can't see how to post to your comment page but you are welcome to put this below up for me Best Peter * Nothing very surprising in Kaufman et al's paper. Back in the 1970's we were all worrying about the overdue ice age.. Then someone remembered Arrhenius and we got to worry (increasingly) about global warming or, as now seems quite possible, climatic catastrophe. Bill Ruddiman's book last year Plows Plagues and Petroleum argues quite plausibly that agricultural clearances, putting forest carbon into the atmosphere, was inadvertant benign geo-engineering that prevented the arrival of the ice age. With industrialization things have got a bit out of hand. Stewart Brand said recently What I'm saying now is we are as gods and have to get good at it. Necessity comes from climate change, potentially disastrous for civilization. The planet will be okay, life will be okay. We will lose vast quantities of species, probably lose the rain forests if the climate keeps heating up. So it's a global issue, a global phenomenon. It doesn't happen in just one area. The planetary perspective now is not just aesthetic. It's not just perspective. It's actually a world- sized problem that will take world sized solutions that involves forms of governance we don't have yet. It involves technologies we are just glimpsing. It involves what ecologists call ecosystem engineering. Beavers do it, earthworms do it. They don't usually do it at a planetary scale. We have to do it at a planetary scale. A lot of sentiments and aesthetics of the environmental movement stand in the way of that. If they continue to stand in the way then truly it is 'the Age of Stupid' Peter Read --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: we're engineering the arctic now
I agree with Alvia about some of the environment left. I call those who oppose most new environmental engineering Dark Greens. They can be easy to detect because many if not most of their arguments end with there are just too many people, leaving the listener wondering what solution is implied by that statement and whether I or thee must be sacrificed. I call myself a Light Green because I believe that wise use of technology offers hope for the future. = Stuart = Stuart E. Strand 167 Wilcox Hall, Box 352700, Univ. Washington, Seattle, WA 98195 voice 206-543-5350, fax 206-685-3836 http://faculty.washington.edu/sstrand/ -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Alvia Gaskill Sent: Friday, September 04, 2009 4:06 AM To: anr...@nytimes.com; geoengineering@googlegroups.com Subject: [geo] Re: we're engineering the arctic now I registered for Dot Earth, but for some reason, the message on this particular one won't allow me to log in. So I ask for you to post it if you wish. Without human interference, the interglacial would still take at least several thousand years to end and the ice sheets to return to cover the northern hemisphere. With it, the interglacial continues. Most likely, the CO2 we have added to the atmosphere will have been removed by some form of air capture in 100-200 years (sorry to disappoint David Archer et al.). Thus, we will have had no impact on preventing the return of the Laurentide Ice Sheet and related ones in Europe and Asia. UNLESS we take the lessons learned from our inadvertent intervention into the climate system and use it to our benefit. One of the definitions of geoengineering that is often used is that of deliberate modification of Earth's environment on a large scale to suit human needs and promote habitability. The needs of the present are to stop the effects of global warming before the planet becomes uninhabitable for humans. Geoengineering in this instance is the use of technologies that stop global warming without reducing emissions of CO2 and other greenhouse gases. But once we can can control the CO2 level in the atmosphere, do we really want it to return to the pre-industrial level? Probably so. That was the level that allowed a stable climate and for human civilization to develop. At some point, probably thousands of years from now, we will want to counteract the natural cycle and prevent the interglacial from ending. By then, we will have developed far more advanced technologies of all types than today and adjusting the climate will be relatively simple. Assuming we survive our current experience with global warming, we will be able to build on it and develop the technologies to modify climate to our needs, back to the first definition. Not surprisingly, there are those on the environmental left who would welcome the return of the ice sheets. One poster at the geoengineering group even said he thought we should allow the ice sheets to cover Canada and the northern U.S. again because the glaciers would scrape up more minerals that could be used. Like we are expecting a shortage of iron and nickel in 8000 AD? He then went on to imagine that the survivors (NY Times won't be able to publish under 2 miles of ice, sorry Andy, must change name of blog to Dot Ice) could all go and live in the tropics, where, of course, food will still be limited due to changes in precipitation and in the subtropics, winds will howl most of the time. The ice age was no picnic, even in the southern U.S. How people come to view humans, their own species as the enemy beats me. We've made some mistakes and they have cost us and other species. But at least we are on the path to the 12 step recovery program by recognizing we have a problem. Is the answer to alcoholism to shoot all the drunks? An even more extreme view shared by many, but voiced by few (for understandable reasons) is that humans are an invasive species that should be eliminated from the planet! Moi kudzu? Do I look like a zebra mussel to you? For this select crowd, I have come up with a suitable name. Cutterites. After the character in the BBC TV series Primeval, Helen Cutter, who became such a misanthrope she went back in time and tried to eliminate all the early humans. I'm sure Helen would not be in favor of continuing the interglacial either. And what happened to her experiment in preventative extinction? She was crushed by a dinosaur that followed her through one of her time portals. Gotta watch out for that technology. It'll get you when you least expect it. Alvia Gaskill Pro-Human Lobbyist - Original Message - From: Andrew Revkin anr...@nytimes.com To: geoengineering@googlegroups.com Sent: Thursday, September 03, 2009 3:40 PM Subject: [geo] we're engineering the arctic now http://www.nytimes.com/2009/09/04/science/earth/04arctic.html
[geo] Re: we're engineering the arctic now
Hi Andrew, Interesting paper, you referred to, published in Science today (4th September). It seems to confirm the Ruddiman hypothesis [1] that we would be in a cooling period of the Milankovitch cycle, if it were not for (inadvertent) climate intervention by mankind. But Ruddiman takes a rather longer view, and considers temperature over the past 8000 years, which has remained pretty steady, allowing civilisations to develop. He shows that mankind's activities over this period have almost exactly countered a natural cooling that would have occurred from the Milankovitch cycles (concerning the Earth's orbit and tilt). But, since the start of industrialisation, we have injected an enormous pulse of CO2 into the atmosphere, as well as methane from livestock. These are already tipping the Earth's climate system towards a much hotter state. The global warming is amplified at the poles. An interesting point from the paper is that the Milankovitch cooling was starting to overcome anthropogenic warming in the Arctic at least two thousand years ago, until the last century, when polar amplification of global warming cut in and the cooling trend reversed. The abstract of the paper is here: http://www.sciencemag.org/cgi/content/short/325/5945/1236 Recent Warming Reverses Long-Term Arctic Cooling Darrell S. Kaufman,1,* David P. Schneider,2 Nicholas P. McKay,3 Caspar M. Ammann,2 Raymond S. Bradley,4 Keith R. Briffa,5 Gifford H. Miller,6 Bette L. Otto-Bliesner,2 Jonathan T. Overpeck,3 Bo M. Vinther,7 Arctic Lakes 2k Project Members The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000. The lesson is surely clear. We have to reduce the CO2 in the atmosphere and cool the polar regions if we are to restore the stability of climate (and sea-level) that we have enjoyed for the past 8000 years. Reducing emissions by itself will have little effect. Cheers from Chiswick, John [1] http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyppothesis/ Andrew Revkin wrote: Apologies to those who are not Dot Earth readers (and I *do* encourage everyone to have a look)... But just to make it clear to all, I do 98 percent of the comment moderation on the blog (no easy task) and there is NO screening or censorship (to the consternation of some, who feel the blog has been taken over by "climate skeptics"). If a comment is on topic and constructive and polite, it gets published. There *have* been significant technical glitches with a transition to a new comment mechanism, so many comments have been lost (by folks of all stripes). I always recommend keeping a copy of text instead of writing the comment in the submission box. Then it can be emailed to me as a backstop. At 8:54 AM -0400 9/4/09, Eugene I. Gordon wrote: Alvia: I too have been cut out of the Dot Earth comments and I have been contributing for a few years. Andy asked me to e-mail him directly and I expect I will have to start doing that if he is careful to suppress my full name, but whoever is screening appears to be anti Geoengineering. You missed one key point. All the climate variations are superimposed on top of an upward trend heading to 25 C even without CO2 increase. As you know this has happened at least 5 times during the 540 million year history of the Earth and is probably related to plate or land mass motion and how it influences ocean currents. No matter what they think about the dangers or risks (pretty stupid to think it would be implemented without risk assessment) geo will prove to be essential to block the increase. It is not going to be either or. -gene -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Alvia Gaskill Sent: Friday, September 04, 2009 7:06 AM To: anr...@nytimes.com; geoengineering@googlegroups.com Subject: [geo] Re: we're engineering the arctic now I registered for Dot Earth, but for some reason, the message on this particular one won't allow me to log in. So I ask for you to post it if you wish. Without human interference, the interglacial would still take at least several thousand years to end and the ice sheets to retur
[geo] Re: we're engineering the arctic now
Again, I emphasize; be precise. We are in a warming period of the
Milankovitch cycle, which afflicts mostly the Antarctic. However the same
tilt cools the Arctic. The cycle will last another 10,000 years but it will
not progress.
From: geoengineering@googlegroups.com
[mailto:geoengineer...@googlegroups.com] On Behalf Of John Nissen
Sent: Friday, September 04, 2009 6:18 PM
To: anr...@nytimes.com
Cc: Eugene I. Gordon; agask...@nc.rr.com; geoengineering@googlegroups.com;
wf...@virginia.edu
Subject: [geo] Re: we're engineering the arctic now
Hi Andrew,
Interesting paper, you referred to, published in Science today (4th
September). It seems to confirm the Ruddiman hypothesis [1] that we would
be in a cooling period of the Milankovitch cycle, if it were not for
(inadvertent) climate intervention by mankind. But Ruddiman takes a rather
longer view, and considers temperature over the past 8000 years, which has
remained pretty steady, allowing civilisations to develop. He shows that
mankind's activities over this period have almost exactly countered a
natural cooling that would have occurred from the Milankovitch cycles
(concerning the Earth's orbit and tilt). But, since the start of
industrialisation, we have injected an enormous pulse of CO2 into the
atmosphere, as well as methane from livestock. These are already tipping
the Earth's climate system towards a much hotter state. The global warming
is amplified at the poles. An interesting point from the paper is that the
Milankovitch cooling was starting to overcome anthropogenic warming in the
Arctic at least two thousand years ago, until the last century, when polar
amplification of global warming cut in and the cooling trend reversed.
The abstract of the paper is here:
http://www.sciencemag.org/cgi/content/short/325/5945/1236
Recent Warming Reverses Long-Term Arctic Cooling
Darrell S. Kaufman,1,* David P. Schneider,2 Nicholas P. McKay,3 Caspar M.
Ammann,2 Raymond S. Bradley,4 Keith R. Briffa,5 Gifford H. Miller,6 Bette L.
Otto-Bliesner,2 Jonathan T. Overpeck,3 Bo M. Vinther,7 Arctic Lakes 2k
Project Members{dagger}
The temperature history of the first millennium C.E. is sparsely documented,
especially in the Arctic. We present a synthesis of decadally resolved proxy
temperature records from poleward of 60°N covering the past 2000 years,
which indicates that a pervasive cooling in progress 2000 years ago
continued through the Middle Ages and into the Little Ice Age. A 2000-year
transient climate simulation with the Community Climate System Model shows
the same temperature sensitivity to changes in insolation as does our proxy
reconstruction, supporting the inference that this long-term trend was
caused by the steady orbitally driven reduction in summer insolation. The
cooling trend was reversed during the 20th century, with four of the five
warmest decades of our 2000-year-long reconstruction occurring between 1950
and 2000.
The lesson is surely clear. We have to reduce the CO2 in the atmosphere and
cool the polar regions if we are to restore the stability of climate (and
sea-level) that we have enjoyed for the past 8000 years. Reducing emissions
by itself will have little effect.
Cheers from Chiswick,
John
[1]
http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyp
pothesis/
Andrew Revkin wrote:
Apologies to those who are not Dot Earth readers (and I *do*
encourage everyone to have a look)...
But just to make it clear to all, I do 98 percent of the comment
moderation on the blog (no easy task) and there is NO screening or
censorship (to the consternation of some, who feel the blog has been
taken over by climate skeptics).
If a comment is on topic and constructive and polite, it gets published.
There *have* been significant technical glitches with a transition to
a new comment mechanism, so many comments have been lost (by folks of
all stripes). I always recommend keeping a copy of text instead of
writing the comment in the submission box. Then it can be emailed to
me as a backstop.
At 8:54 AM -0400 9/4/09, Eugene I. Gordon wrote:
Alvia:
I too have been cut out of the Dot Earth comments and I have been
contributing for a few years. Andy asked me to e-mail him directly and I
expect I will have to start doing that if he is careful to suppress my full
name, but whoever is screening appears to be anti Geoengineering.
You missed one key point. All the climate variations are superimposed on top
of an upward trend heading to 25 C even without CO2 increase. As you know
this has happened at least 5 times during the 540 million year history of
the Earth and is probably related to plate or land mass motion and how it
influences ocean currents.
No matter what they think about the dangers or risks (pretty stupid to think
it would be implemented without risk assessment) geo will prove to be
essential to block the increase. It is not going to be either or.
-gene
-Original
[geo] Re: we're engineering the arctic now
probably I'm being stupid but it seems to me that if earth is tilted a bit more it will present more arctic to the sun in the northern summer and more antarctic to the sun in the southern summer ?? And ditto for elipticity (though I don't think it needs coincide with tilt?)??. As for precession, that's too much for me. Peter - Original Message - From: Eugene I. Gordon To: j...@cloudworld.co.uk ; anr...@nytimes.com Cc: agask...@nc.rr.com ; geoengineering@googlegroups.com ; wf...@virginia.edu Sent: Saturday, September 05, 2009 11:48 AM Subject: [geo] Re: we're engineering the arctic now Again, I emphasize; be precise. We are in a warming period of the Milankovitch cycle, which afflicts mostly the Antarctic. However the same tilt cools the Arctic. The cycle will last another 10,000 years but it will not progress. From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of John Nissen Sent: Friday, September 04, 2009 6:18 PM To: anr...@nytimes.com Cc: Eugene I. Gordon; agask...@nc.rr.com; geoengineering@googlegroups.com; wf...@virginia.edu Subject: [geo] Re: we're engineering the arctic now Hi Andrew, Interesting paper, you referred to, published in Science today (4th September). It seems to confirm the Ruddiman hypothesis [1] that we would be in a cooling period of the Milankovitch cycle, if it were not for (inadvertent) climate intervention by mankind. But Ruddiman takes a rather longer view, and considers temperature over the past 8000 years, which has remained pretty steady, allowing civilisations to develop. He shows that mankind's activities over this period have almost exactly countered a natural cooling that would have occurred from the Milankovitch cycles (concerning the Earth's orbit and tilt). But, since the start of industrialisation, we have injected an enormous pulse of CO2 into the atmosphere, as well as methane from livestock. These are already tipping the Earth's climate system towards a much hotter state. The global warming is amplified at the poles. An interesting point from the paper is that the Milankovitch cooling was starting to overcome anthropogenic warming in the Arctic at least two thousand years ago, until the last century, when polar amplification of global warming cut in and the cooling trend reversed. The abstract of the paper is here: http://www.sciencemag.org/cgi/content/short/325/5945/1236 Recent Warming Reverses Long-Term Arctic Cooling Darrell S. Kaufman,1,* David P. Schneider,2 Nicholas P. McKay,3 Caspar M. Ammann,2 Raymond S. Bradley,4 Keith R. Briffa,5 Gifford H. Miller,6 Bette L. Otto-Bliesner,2 Jonathan T. Overpeck,3 Bo M. Vinther,7 Arctic Lakes 2k Project Members The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000. The lesson is surely clear. We have to reduce the CO2 in the atmosphere and cool the polar regions if we are to restore the stability of climate (and sea-level) that we have enjoyed for the past 8000 years. Reducing emissions by itself will have little effect. Cheers from Chiswick, John [1] http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyppothesis/ Andrew Revkin wrote: Apologies to those who are not Dot Earth readers (and I *do* encourage everyone to have a look)... But just to make it clear to all, I do 98 percent of the comment moderation on the blog (no easy task) and there is NO screening or censorship (to the consternation of some, who feel the blog has been taken over by climate skeptics). If a comment is on topic and constructive and polite, it gets published. There *have* been significant technical glitches with a transition to a new comment mechanism, so many comments have been lost (by folks of all stripes). I always recommend keeping a copy of text instead of writing the comment in the submission box. Then it can be emailed to me as a backstop. At 8:54 AM -0400 9/4/09, Eugene I. Gordon wrote: Alvia: I too have been cut out of the Dot Earth comments and I have beencontributing for a few years. Andy asked me to e-mail him directly and Iexpect I will have to start doing
