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| Image from the earlier post: Accelerated Arctic Warming |
As has been described in earlier posts at this blog, the current speed of change is unprecedented in history, and this is destabilizing the Arctic and threatening to unleash huge amounts of methane from the seabed and escalate into runaway warming. Comprehensive and effective action is therefore desperately needed.
Views on this from other people follow below.
Paul Beckwith:
Basic premise about stability of Greenland Ice sheet is wrong. In previous interglacials summers were much hotter but winters were much colder (more extreme seasonality); this helped maintain both sea ice and Greenland ice. CO2 and CH4 stayed within narrow bands much lower than now. Now, reason for melt is completely different. GHG much higher now; temps higher year round so recovery less robust in winter. Before troposphere and stratosphere warmed; now troposphere warming like crazy and stratosphere cooling. Lapse rates did not change much before, now lapse rate is slower so more warming higher up (recall extreme melt at 3100 m on Greenland peak; in fact on entire Greenland surface; well 97%). Daily lows much higher now then before due to GHG trapping at night; not the case before. GHG concentrated more at pole since tropopause only 7 km high (compared to CH4 wetland emissions from wetlands near equator where tropopause is 17 km high). Over Greenland summit only 4km up to tropopause). Also more black carbon now to kill snow/ice albedo. Not looking too good for the home team (us).
Also, with warmer upper troposphere from reduced lapse rate colder stratosphere now (not so in previous interglacials) there is no surprise that SSWs (sudden stratospheric warming) events are occurring more frequently...
Further views will be added below. Please comment!
I'd like to see a longer time horizon, say 2 million years?
ReplyDeleteYes, it's good to compare things over longer periods. Apart from comparing temperatures and greenhouse gas levels, it's also important to check where conditions were similar and where they were different in the past. At some periods in history, temperatures and greenhouse gas levels may have been higher than they are now. However, in such cases some crucial circumstances were different. As an example, way back in history CO2 levels may have been higher, but solar output was much lower than current levels, and that is why runaway global warming didn't occur then. Similarly, in the more recent (paleo-)past, temperatures may have been higher in some periods, but these temperatures peaks were reached relatively slowly, as they were driven by slow Milanchovich cycles. We're currently at (or rather passed) the peak of a Milanchovich cycle, so temperatures should be falling (slowly), but instead they are rising rapidly, due to emissions by people.
DeleteAs I said, when comparing the current situation with the past, it's important to check whether conditions were different then. Methane can be broken down naturally, as long as methane emissions are moderate and take place slowly, i.e. over a long period of time. The big danger we're facing now is that temperatures are rising so rapidly in the Arctic that the resulting methane emissions will overwhelm the capacity of nature to process it, which will extend methane's lifetime, further accelerating the temperature rise in a vicious cycle that escalates into runaway global warming.
The exponential rise in jet stream swing means we have limited time to speak. Constructive idea #1 should be getting a shift in the valuation of money so it reflects its effect on Earth through the value of its use toward keeping Earth alive.
ReplyDeleteOption. Thee is hurt and dying and we need help.
Discussion is over and lock in is enabled unless we vanguard a change to world politic and bring war to heel and reengage with Natural open system.
Thanks for commenting, Dale. One way to change the false economy of the moment is to put more value on soil carbon, e.g. as discussed at the Biochar Economy - local council rates could incorporate feebates, i.e. higher fees if soil carbon content goes down and rebates on the rates where soil carbon goes up. This could be implemented in a budget-neutral way, i.e. the fees imposed on the worst cases pay for the rebates that reward the best achievers.
DeleteSuch feebates could be implemented as part of a wider comprehensive and effective climate plan.
Sam, the Arctic Methane Emergency Group put plan forward on Dec 7th and gave two months in which mankind could realistically act and it appears that time period is about over you have to admit, Even more so because of CH4 release around Svalbard and Barents Sea in January; that drastic world wide change is needed now to have hope. Somehow we need to change direction of habit from where options narrow to that that naturally opens like a flower. If perhaps we alter the root at the core of the malfunctioning world monetary system a systemic change could transition to a place similar to Nature's open systems. Where things tend to heal and grow better.. A change to the valuation of money with sudden affect.
DeleteHi Dale, I'm quite aware of AMEG's plan and, as I said below, I do see solar radiation management as an indispensable part of the necessary action. Nonetheless, multiple lines of action are needed in parallel, e.g. to avoid soot that is threatening to cause further loss of reflectivity, we also need to give more attention to ways to break down methane, etc., so I like to advocate the comprehensive and effective Climate Plan that I seek people to support.
DeleteIt seem to me that the only options left are for radical multi-pronged geo-engineering efforts. Right now we need short term solutions.
ReplyDeleteIMO, mid to long term economic solutions are certainly still needed, but right now we just need to stop the radiative forcing before it hits the earth, or reflect a lot more of it back.
Solar radiation management certainly is an indispensable part of the necessary action. Nonetheless, multiple lines of action are needed in parallel, for starters to avoid soot that is threatening to cause further loss of reflectivity. I therefore propose a comprehensive and effective Climate Plan.
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