This is jonthed's Typepad Profile.
Join Typepad and start following jonthed's activity
Join Now!
Already a member? Sign In
jonthed
Recent Activity
Everybody must surely agree, experts included, that the dynamics of an ice sheet as thick as the GIS when subjected to a change in weather as severe and abrupt as what it is experiencing, are highly complex and unknown. But so many people's approach seems to be fairly simplistic and dismissive, 'glacial pace' crops up all the time. But with more and more warm melt water working its way over, through, and under the ice, surely the effect is not as simple as surface melt and glacial calving. The whole ice sheet could (will?) become riddled with cracks, holes, gullys, caverns, etc. not to mention the base lubrication, all of which massively increase the amount of surface area exposed to warmer water, and the melt and erosion that that will bring. And this is deep into the core of the ice sheet. It will be eaten away in 3 dimensional space, not just the surface. Like a bone with osteoporosis. Its integrity will weaken and parts will start crumbling. Whilst calving might speed up with the added lubrication and melt water action, I see the largest threat to the ice sheet as the melt water itself. Eating away and destabilising the ice sheet form the inside. Particularly if we are to see larger melt areas more frequently as the weather patterns change. I'll be very interested to see how measurements of melt water runoff and ice sheet mass loss develop in the next few decades. Sure it might all be a bit unknown, and hard to model or predict. But we can't just assume a simple model and be satisfied with that.
Has anyone seen any discussion of this recent paper? http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00175.1 seems to be one of the most recent on the topic. This is the MIT News article about his research that Rose links to from his website: http://web.mit.edu/newsoffice/2013/demystifying-the-cretaceous-hothouse.html
Toggle Commented Jul 30, 2013 on Second storm at Arctic Sea Ice
This discussion of a transition to a single cell northern hemisphere is, unfortunately, news to me, and has indeed added to my feelings of dread. Thank you so much for bringing this to my attention (not being sarcastic btw). So, as pointed out, if the earth can exist in a dual climate state (NH hot-house, SH ice-house) then global warming is not the immediate concern, but northern hemisphere warming is! Instead of getting concerned as we watch the global average temperatures rise, should we be focussing (for now) on solely the northern hemisphere temperatures, and, having filtered out the more moderate increases seen in the SH, be getting even more concerned! I wondered what a graph showing warming by hemisphere would reveal (a quick google found data sets for hemispheres from NASA GISS, and also this graph: http://www.giss.nasa.gov/research/news/20100121/418334main_hemi-temp-full.jpg ) So, as already said by others, tipping the NH climate into a new state is much closer than a 'global' change seemed to be. And with it come huge changes to weather patterns, and enough warmth to unleash the arctic carbon. Seems that it really is NH warming that needs to be at the forefront of discussion, not global warming. Is there any indication that climate science is picking up on this? If not we need to get much more scientists to get to work on this. - One question, in the hothouse/icehouse dual state, what effect would this have on the ENSO, and its effect on global temperatures?
Toggle Commented Jul 29, 2013 on Second storm at Arctic Sea Ice
I still don't understand this mentality of obsessing over what is 'most likely' to happen, and refusing to take the 'less likely' scenarios into account when deciding how seriously we should view our current situation, particularly when some of those less likely scenarios result in global catastrophe. Same as the IPCC emissions scenario projections. The fact that 8C warming is even on the table surely should mean we take the most aggressive reductions path possible. Not just carry on BAU and think 'well it could only be 2C'.
Toggle Commented Jul 29, 2013 on Arctic time bombs at Arctic Sea Ice
Am I to understand that people are down playing the threat of a sudden methane release because there were warmer times in the deep past that had no such sudden release? Surely that's completely disregarding the difference in rate of change between current warming and previous natural warmings? If previous warm periods came about slowly due to natural changes in the forcings (milankovitch cycles etc.) and methane is a short lived ghg, then there would of course not be a sudden methane pulse. However, current rate of warming is so much faster and if the same amount of methane is to be released but over a much shorter time scale then surely the feedback will be much stronger and the threat of sudden methane release much more probable. What am I missing? Also, there are so many potential disaster scenarios with climate change, that just because we don't know with accuracy what will happen, the fact that there are multiple threats and that if even just one of them is worse than the optimistic scenarios then the world is going to be in for a very rough time, surely should warrant serious action. It seems like we're playing russian roulette with a gun that we don't know how many bullets are in, but we're hoping it's actually empty, so we play on.
Toggle Commented Jul 26, 2013 on Arctic time bombs at Arctic Sea Ice
Surprised you genuinely seem pleased with the volume increase Neven. As Danny has already pointed out, the arctic is already gone, and as Espen says, it's like watching someone on their death bed, and getting excited that one particular painful gasp of breath was less rattly than the last one. The ice is gone, the climate still has a long way to go to reach equilibrium again even if we stopped emitting tomorrow. I must say I think that another record breaking year and new low for the arctic may be more beneficial to the climate than a debatable "recovery". We need action ASAP, disappearing arctic ice may be our best shot at getting enough people concerned. I don't want the skeptics to have more fuel for the doubt machine, that would only delay action, and not save the arctic anyway. This is bad news to me, but I still think we'll be in for a new low this year, so we'll see what the public make of it then. Keep up the good work, and I love that slogan Scarlet P!
Toggle Commented Mar 13, 2013 on PIOMAS March 2013 at Arctic Sea Ice
jonthed is now following The Typepad Team
Mar 12, 2013