Re: functionally Re: [geo] September sea-ice gone by end of century? (or much sooner)
absolutely. now we need a way to communicate this. A few years ago, we moved from talking about the extent to depth and volume. Perhaps this September, a new narrative can emerge about the functionality of the sea ice rather than the extent. I think this reinforces the need for active intervention to stabilise the Arctic and restore the sea ice, or at least its functionality. very best wishes, Emily. On 18/07/2011 22:16, Mike MacCracken wrote: The sea ice is already becoming dysfunctional in a number of ways--for some marine animals, for indigenous communities on barrier islands (absence means less suppression of winter storm waves), indigenous hunting at certain times of the year is disrupted, disruption of the creation of the very cold air of the Arctic in some seasons (so we have a longer season with the Arctic supplying a lot of heat to the atmosphere and affecting the weather in mid-latitudes), etc. Even thin ice or shorter ice-in situations leads to dysfunction--we don't have to wait until 100% is gone in a particular season, etc. Mike On 7/18/11 5:00 PM, Emilyem...@lewis-brown.net wrote: hi thanks, extinct, I think means it isn't in the wild or captivity for 30 years... which is a long time to wait. The point I'm making is that other terms are created when there is little sense in waiting for 30 years for non existence to exist... The point about sea ice, is an important one. Communicating an issue is key. If, as is possible, that some sea ice remains in pockets or as a thin film over the Arctic in areas at some times of the year, do we wait before accepting that the ecosystem is functionally, well, dysfunctional? I think a term can be adopted in this case, which refers to the sea ice as so severely reduced that it is no longer performing its critical previous functions. Communicating in phrases and terms which are accurate but also readily accessible is key. I am not sure what the correct phrase for the diminishing sea ice is, and I am hopeful that we wont need one. I am optimistic that we will restore the Arctic ecosystem, just as we re plant a forest when we realise we need it, we clean up an oil spill, and we clean up a coal spoil heap. thanks so much, Emily. On 18/07/2011 21:50, Mike MacCracken wrote: For species, I have heard (e.g., from reviewers when I have misused the word extinct) that when there are no more in a region or in the wild, the appropriate term is (from biology online): Extirpation The act of extirpating or rooting out, or the state of being extirpated; eradication; excision; total destruction; as, the extirpation of weeds from land, of evil from the heart, of a race of men, of heresy. Extinction only applies when there are none either in the wild or in captivity. I am not sure that applying this word to sea ice would work very well, however. Mike MacCracken On 7/18/11 3:53 PM, Emilyem...@lewis-brown.net wrote: Hi, a term used for species extinctions comes to mind - when a species is reduced to such a small number of animals in the wild but isn't extinct, it is sometimes referred to as 'functionally extinct'. If we consider the functions of the Arctic sea ice - in areas it is pretty near functionally extinct already... eg in Hudson Bay... Sea ice performs so many different functions it's hard to even list them. best wishes, Emily. On 18/07/2011 17:24, rongretlar...@comcast.net wrote: Ken (cc list) I have tried (as a rank amateur observer, not participant) to follow this retreatjng September arctic ice topic for the last 5 years. I have come to a different conclusion than expressed in your two articles.. The website I have found most valuable can be located by remembering the name Neven - and googling with arctic and ice . This blog averages more than one message per hour - and the folks commenting there seem to be putting a lot of time into the topic. Not experts on this blog, but dedicated amateurs, who do seem to be talking to the ice experts, however. The key question is what are we to be measuring when we talk of gone? I gather that 10% remainder is considered gone. One also has to consider whether one will be talking area, extent, or volume. I like the volume definition - as thickness is dropping much more rapidly than area (the smaller number) or extent - and the volume is easier to find data on than thickness. A good (April 2011) discussion of these differences is at http://neven1.typepad.com/blog/2011/04/trends-in-arctic-sea-ice-volume.html #m ore This short write-up, using experimental volume data, suggests about 2016 as a best guess to get to this 10% value. This uses a Gompertz model - which has no particular theoretical validity - but seems to have more validity than a linear or quadratic approach to absolute zero. It might be overly conservative. For today's blog exchange (several dozen so far today), go to just the early part of the above URL. The modeler who seems (to me) to
Re: [geo] September sea-ice gone by end of century? (or much sooner)
http://dotearth.blogs.nytimes.com/2010/03/22/new-light-shed-on-north-pole-ice-trends/ The bottom line, expressed here before, is that no one should expect to find much broad meaning in short-term variability in Arctic sea ice — in one direction or the other. If there is a death spiral, expect a lot of loop the loopshttp://dotearth.blogs.nytimes.com/2009/10/06/spread-of-thicker-arctic-ice-seen-last-summer/along the way. Those most passionately pushing for and against action on greenhouse gases have a tendency to jump to the National Snow and Ice Data Center Web site to chart each wiggle. On Mon, Jul 18, 2011 at 8:41 AM, Ken Caldeira kcalde...@dge.stanford.eduwrote: Folks, There has been a fair amount of discussion on this group that talks about imminent September sea ice loss in the Arctic. The attached paper indicates that around half of the normal September sea-ice should still be around in the 2020-2040 time frame. Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009). I am not saying that the situation in the Arctic is not dire, however, are the suggestions that September sea-ice in the Arctic is soon to be a thing of the past a bit overblown and without foundation? Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- 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. -- *Please excuse typos; as you may be aware, I had a stroke 1 Julyhttp://dotearth.blogs.nytimes.com/2011/07/01/time-for-a-checkup/ .* ANDREW C. REVKIN Dot Earth blogger, The New York Times http://www.nytimes.com/dotearth Senior Fellow, Pace Acad. for Applied Env. Studies Cell: 914-441-5556 Fax/voicemail: 509-357-0965 Twitter: @revkin Skype: Andrew.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.
RE: [geo] September sea-ice gone by end of century? (or much sooner)
I would just ask people to draw attention to sea ice volume models. In addition to look at i.e. Cryosphere Today how the terrestrial defrost progressed this year, and check out temperature legend maps for North Canada and Siberia. How many natural processes behave the same way on their very last legs as they do in the mid journey. Almost none. Date: Mon, 18 Jul 2011 13:04:34 -0400 Subject: Re: [geo] September sea-ice gone by end of century? (or much sooner) From: rev...@gmail.com To: kcalde...@gmail.com CC: geoengineering@googlegroups.com http://dotearth.blogs.nytimes.com/2010/03/22/new-light-shed-on-north-pole-ice-trends/ The bottom line, expressed here before, is that no one should expect to find much broad meaning in short-term variability in Arctic sea ice — in one direction or the other. If there is a death spiral, expect a lot of loop the loopsalong the way. Those most passionately pushing for and against action on greenhouse gases have a tendency to jump to the National Snow and Ice Data Center Web site to chart each wiggle. On Mon, Jul 18, 2011 at 8:41 AM, Ken Caldeira kcalde...@dge.stanford.edu wrote: Folks, There has been a fair amount of discussion on this group that talks about imminent September sea ice loss in the Arctic. The attached paper indicates that around half of the normal September sea-ice should still be around in the 2020-2040 time frame. Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009). I am not saying that the situation in the Arctic is not dire, however, are the suggestions that September sea-ice in the Arctic is soon to be a thing of the past a bit overblown and without foundation? Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- 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. -- Please excuse typos; as you may be aware, I had a stroke 1 July.ANDREW C. REVKINDot Earth blogger, The New York Timeshttp://www.nytimes.com/dotearthSenior Fellow, Pace Acad. for Applied Env. StudiesCell: 914-441-5556 Fax/voicemail: 509-357-0965 Twitter: @revkin Skype: Andrew.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. -- 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.
RE: [geo] September sea-ice gone by end of century? (or much sooner)
At last some sanity. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Revkin Sent: Monday, July 18, 2011 1:05 PM To: kcalde...@gmail.com Cc: geoengineering Subject: Re: [geo] September sea-ice gone by end of century? (or much sooner) http://dotearth.blogs.nytimes.com/2010/03/22/new-light-shed-on-north-pole-ic e-trends/ The bottom line, expressed here before, is that no one should expect to find much broad meaning in short-term variability in Arctic sea ice - in one direction or the other. If there is a death spiral, expect http://dotearth.blogs.nytimes.com/2009/10/06/spread-of-thicker-arctic-ice-s een-last-summer/ a lot of loop the loopsalong the way. Those most passionately pushing for and against action on greenhouse gases have a tendency to jump to the National Snow and Ice Data Center Web site to chart each wiggle. On Mon, Jul 18, 2011 at 8:41 AM, Ken Caldeira kcalde...@dge.stanford.edu wrote: Folks, There has been a fair amount of discussion on this group that talks about imminent September sea ice loss in the Arctic. The attached paper indicates that around half of the normal September sea-ice should still be around in the 2020-2040 time frame. Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009). I am not saying that the situation in the Arctic is not dire, however, are the suggestions that September sea-ice in the Arctic is soon to be a thing of the past a bit overblown and without foundation? Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 tel:%2B1%20650%20704%207212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- 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 mailto:geoengineering%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- Please excuse typos; as you may be aware, I had a stroke 1 July http://dotearth.blogs.nytimes.com/2011/07/01/time-for-a-checkup/ . ANDREW C. REVKIN Dot Earth blogger, The New York Times http://www.nytimes.com/dotearth Senior Fellow, Pace Acad. for Applied Env. Studies Cell: 914-441-5556 Fax/voicemail: 509-357-0965 Twitter: @revkin Skype: Andrew.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. -- 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.
RE: [geo] September sea-ice gone by end of century? (or much sooner)
Schaeffer et al have already estimated c fluxes from permafrost at ~1.8Gtpa over coming decades. Some of these fluxes may be methane, and the process will be accelerated by feedbacks However, it is likely of course that premature thaw of the arctic will accelerate this process. I wonder if anyone can hazard a guess at the new c fluxes we might have to face as a result of the rapid sea ice loss currently observed? A On 19 Jul 2011 09:52, Veli Albert Kallio albert_kal...@hotmail.com wrote: I would just ask people to draw attention to sea ice volume models. In addition to look at i.e. Cryosphere Today how the terrestrial defrost progressed this year, and check out temperature legend maps for North Canada and Siberia. How many natural processes behave the same way on their very last legs as they do in the mid journey. Almost none. Date: Mon, 18 Jul 2011 13:04:34 -0400 Subject: Re: [geo] September sea-ice gone by end of century? (or much sooner) From: rev...@gmail.com To: kcalde...@gmail.com CC: geoengineering@googlegroups.com http://dotearth.blogs.nytimes.com/2010/03/22/new-light-shed-on-north-pole-ice-trends/ The bottom line, expressed here before, is that no one should expect to find much broad meaning in short-term variability in Arctic sea ice — in one direction or the other. If there is a death spiral, expect a lot of loop the loopsalong the way. Those most passionately pushing for and against action on greenhouse gases have a tendency to jump to the National Snow and Ice Data Center Web site to chart each wiggle. On Mon, Jul 18, 2011 at 8:41 AM, Ken Caldeira kcalde...@dge.stanford.edu wrote: Folks, There has been a fair amount of discussion on this group that talks about imminent September sea ice loss in the Arctic. The attached paper indicates that around half of the normal September sea-ice should still be around in the 2020-2040 time frame. Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009). I am not saying that the situation in the Arctic is not dire, however, are the suggestions that September sea-ice in the Arctic is soon to be a thing of the past a bit overblown and without foundation? Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- 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. -- Please excuse typos; as you may be aware, I had a stroke 1 July.ANDREW C. REVKINDot Earth blogger, The New York Timeshttp:// www.nytimes.com/dotearthSenior Fellow, Pace Acad. for Applied Env. StudiesCell: 914-441-5556 Fax/voicemail: 509-357-0965 Twitter: @revkin Skype: Andrew.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. -- 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. -- 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.
Re: [geo] Digest for geoengineering@googlegroups.com - 9 Messages in 1 Topic
In discussing what defines functionally extinct ice, it's also clear that the term ice-free arctic is not well defined: if ice extent is generally defined as the area with 15% continuous ice cover, then the whole arctic as ice free seems to be starting to get defined in some circles as that percentage cover (which itself seems somewhat arbitrary, and, I believe, originates from issues of navigability and not from any 'vital functions') being confined to 1 million sq km. From a recent paper, (Wang and Zhang, 2010): Following Wang and Overland (2009), the ice-free state is defined as occurring when the total September Arctic Ocean sea ice extent, the area with a sea ice concentration ≥15%, is less than 1 million km2. This cutoff is used because models suggest that even when the Arctic can be considered ‘‘nearly sea ice free’’ at the end of the summer, the regions north of Greenland and Canada will still retain some sea ice. But in the Boe et al paper that Ken posted, this doesn't seem to have been followed, and perhaps partly thus the low probability of ice-free conditions coming soon? - On the basis of our approach, there is a probability of 16% that at least 20% of the baseline sea-ice cover in September remains at the end of the twenty-first century and the same probability that the ice disappears completely by 2046-2065. And since all of this only concerns extent and not volume, and yet we know that thickness is vital to stability, isn't this really all just a house of cards, as far as accurately predicting the future path of the arctic? I agree with Ron about Maslowski.. Cheers, Nathan On Tue, Jul 19, 2011 at 7:39 AM, geoengineering+nore...@googlegroups.comwrote: Today's Topic Summary Group: http://groups.google.com/group/geoengineering/topics - September sea-ice gone by end of century? (or much sooner)#1314231fd53034d0_group_thread_0[9 Updates] Topic: September sea-ice gone by end of century? (or much sooner)http://groups.google.com/group/geoengineering/t/d416291f7ce28ab7 Ken Caldeira kcalde...@carnegie.stanford.edu Jul 18 02:41PM +0200 ^#1314231fd53034d0_digest_top Folks, There has been a fair amount of discussion on this group that talks about imminent September sea ice loss in the Arctic. The attached paper indicates that around half of the normal September sea-ice should still be around in the 2020-2040 time frame. Boe, J., Hall, A., Qu, Z. Nature Geosci 2, 341-343 (2009). I am not saying that the situation in the Arctic is not dire, however, are the suggestions that September sea-ice in the Arctic is soon to be a thing of the past a bit overblown and without foundation? Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira rongretlar...@comcast.net Jul 18 04:24PM ^#1314231fd53034d0_digest_top Ken (cc list ) I have tried (as a rank amateur observer, not participant) to follow this retreatjng September arctic ice topic for the last 5 years. I have come to a different conclusion than expressed in your two articles.. The website I have found most valuable can be located by remembering the name Neven - and googling with arctic and ice . This blog averages more than one message per hour - and the folks commenting there seem to be putting a lot of time into the topic. Not experts on this blog, but dedicated amateurs, who do seem to be talking to the ice experts, however. The key question is what are we to be measuring when we talk of gone? I gather that 10% remainder is considered gone. One also has to consider whether one will be talking area, extent, or volume. I like the volume definition - as thickness is dropping much more rapidly than area (the smaller number) or extent - and the volume is easier to find data on than thickness. A good (April 2011) discussion of these differences is at http://neven1.typepad.com/blog/2011/04/trends-in-arctic-sea-ice-volume.html#more This short write-up, using experimental volume data, suggests about 2016 as a best guess to get to this 10% value. This uses a Gompertz model - which has no particular theoretical validity - but seems to have more validity than a linear or quadratic approach to absolute zero . It might be overly conservative. For today's blog exchange (several dozen so far today), go to just the early part of the above URL. The modeler who seems (to me) to have done the best job in modeling this (the subject of Ken's two articles) is Dr. Wieslaw Maslowski who has supported this 2016 gone date since 2008 or so (and again this year). The following 2008 cite is given in the
