7 ms·
Greenland ice sheet climate disequilibrium and committed (274mm) sea-level rise
- soperj 4y ago> The high-melt year of 2012 applied in perpetuity yields an ice loss commitment of 782 ± 135 mm SLR, serving as an ominous prognosis for Greenland’s trajectory through a twenty-first century of warming. It's been a decade now and we haven't had any years really even close to 2012 in terms of minimum sea ice extent.
- Retric 4y agoThat’s false. Compare 1980 was 7.54 million, 2000 was 5.98 million, 2012 was 3.39 million, and 2020 was 3.82 million. https://climate.nasa.gov/vital-signs/arctic-sea-ice/ https://climate.nasa.gov/vital-signs/arctic-sea-ice/ It is noisy data with few data points, so yes 2013 was 5.05 million but both the peaks and troughs are dropping.
- soperj 4y agothat's over a 10% difference between 2020 & 2012, and it was the only year under 4 million, so my point still stands.
- cheath 4y agoWhat is the point that still stands, exactly? There are peaks and troughs with a clear downward trend. If your point is that in that trend, some years over 10 year periods look similar, then you would be correct. But in making that point, you risk drawing the wrong conclusion from the data.
- soperj 4y agoMy point was that you shouldn't base a prognosis on a melt year that has happened once in a 40 year record, when it so far has been an anomaly.
- bobkazamakis 4y agodata that I don't like is an abberation. data that I do like is proof!
- soperj 4y agothat's nonsense. It hasn't happened again in a decade despite the last 5 years being some of the warmest on record, and there was a cyclone that ripped through arctic dispersing sea ice in early August that year. It's clearly an anomaly.
- Retric 4y agoBeing 2 standard deviations from the trend line is hardly an anomaly, just expected variance over a sample that size. 0.05 * 40 = 2.
- carrychains 4y agoYour definition of "really even close" is either absurd or you don't much care about the data nearly as much as the point you wanted to make.
- soperj 4y agoDo you understand the point I'm trying to make? Because it doesn't really seem like it.
- praestigiare 4y agoThe 20 years leading up to 2004 the average was > 6 million square km. 2012 was 3.4. 2020 was 3.8. In the context of the previous average, that does seem close. What was your point?
- soperj 4y agoMy point was don't base a prognosis on an anomaly, but clearly everyone has taken it as something else entirely, based on the tones of the replies.
- anonporridge 4y agoA different visualization of the same data here, https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ https://nsidc.org/arcticseaicenews/charctic-interactive-sea-...
- pier25 4y agoI guess it depends how you define "close". All years from the last decade look pretty close to me: http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger... See the PIOMAS project data: http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/ http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volum...
- soperj 4y agoI'm not sure how they got data going to the end of 2022? This also doesn't show a low point in 2012, so can't be what they're basing it on.
- czinck 4y agoThe red line (2022 data) stops at July, and while it's hard to tell exactly it looks to me like the diamond line (not sure what to call that color) for 2012 is the lowest line between August and October.
- soperj 4y agoAhhh i see it now, 2 red lines with pluses. I was looking at 2015. That makes wayyy more sense.
- pier25 4y agoThere are multiple years show. The PIOMAS project has been collecting data with a satellite over the Arctic since 1979 IIRC.
- soperj 4y agoThe PIOMAS project is just a calculation based on other satellite observations, the model has been verified using 2 different satellites, one launched in 2003, and another in 2010. [0] Their paper on the model was released in 2003. My mistake was that I was looking at the 2015 line, because the color and design looks exactly like 2022. [0] - https://en.wikipedia.org/wiki/Measurement_of_sea_ice#Sea_ice_volume https://en.wikipedia.org/wiki/Measurement_of_sea_ice#Sea_ice...
- jackmott42 4y agoExtent tends to be a noisier signal that total ice mass.
- soperj 4y agoI agree entirely, but it seems that they're basing their calculation off of extent rather than volume, because 2012 isn't the low point volume.
- enviclash 4y agoThe West Antarctic Ice Sheet is much bigger a problem, and is following suite. Source: https://www.nationalgeographic.com/environment/article/west-antarctic-glaciers-melting-human-influence https://www.nationalgeographic.com/environment/article/west-...
- the_third_wave 4y agohttp://polarportal.dk/groenland/iskappens-overflade/#c7242 http://polarportal.dk/groenland/iskappens-overflade/#c7242 Here you can follow the accumulation - Greenland has a net accumulation of snow/ice every year - over the last months and years. This year has seen less melt/more accumulation than the average for the last 40 years. Go back to 2016 for the last period of high melt/low accumulation, 2010-2012 saw the highest melt/lowest accumulation in the last ~70 years. At this moment the runoff of water from Greenland is comparable to that in the 1950's [1 - select 'Run off' on polarportal.dk to get this graph]. As to why the authors suggest the application of the highest melt in 70 years - which, as is shown by the graph, clearly stands out from the rest - 'in perpetuity' I'll leave up to the readers to decide. [1] http://polarportal.dk/fileadmin/_processed_/csm_tasersuaq_cee23cbc18.jpg http://polarportal.dk/fileadmin/_processed_/csm_tasersuaq_ce...
- olddustytrail 4y agoJust to ensure nobody is fooled by this idiot, the SMB clearly states: "It does not include the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater. " English version at http://polarportal.dk/en/greenland/surface-conditions/ http://polarportal.dk/en/greenland/surface-conditions/
- the_third_wave 4y agoNice snub. Realise why those glaciers calve off icebergs - it is related to the flow of the glacier which is in turn a function of the amount of mass accumulated. As to those icebergs 'melting in contact with warm seawater' I can add that this is what icebergs do when they come into contact with seawater - they melt. Did you think they just stayed around forever to accumulate somewhere in a giant iceberg pileup? Nope, they melt and return the water to the ocean from where it eventually evaporates for a new cycle. So before you call someone an 'idiot' I'd suggest you read up on the subject so as to make yourself look like less of one.
- olddustytrail 4y ago
- paulbaumgart 4y agoHow much wiggle room is there in the conclusion that this is level of sea level rise is going to happen “regardless of twenty-first-century climate pathways”? For example, and setting aside feasibility, if carbon dioxide levels were reduced back down to pre-industrial levels, would that amount of sea level rise still be locked in? Or would the ice stop melting and even gradually re-freeze?
- bmismyname 4y agoIt depends on who you ask, but I've seen estimates that suggest at least 10m of sea level rise is already "priced in", so to speak. In the climate crisis discussion communities there's a saying that things are happening "faster than expected", which also applies to the fact that most of the accepted climate models are much more conservative than they should be. The IPCC models (for example) largely ignore tipping points and methane emissions, and their contribution to the exponential rate of increase in climate change. At this point we're not going to do what's needed to make things less bad (i.e., keeping the carbon in the ground) so my suggestion is to plan for the worst and hope for the best.
- cgb223 4y agoIs there a map somewhere that simulates various coastline changes based on sea level rise? Ex: the 10 meters mentioned above
- bmismyname 4y agoGood question, there are several, but the one I've played with is this tool from the NOAA: https://coast.noaa.gov/slr/ https://coast.noaa.gov/slr/ I've used this tool to inform my decisions with regard to planning for my climate mitigation strategy.
- tuatoru 4y agoA better question would be, is there a map that shows the extended inland reach of the more violent storms that we will get with a warmer atmosphere? Planning on the basis of the ocean being a mill-pond won't go very well.
- mylons 4y agoif we start mass desalination (just assume we can), would that have any impact on sea levels? what if it were on a scale of irrigating deserts, etc?
- dsq 4y agoAt some point all excess water flows to the sea or evaporates into the atmosphere, where it turns to rain and then to the sea. So sea (ocean, really) levels do not change.
- mym1990 4y agoI mean at a fundamental level if you can take out the same amount of water(or more) as is melting, yes. But I think from the shear size of the problem, most people have a hard time reasoning about just how much water we are talking about.
- jeffbee 4y agoThere was a proposal to just pump seawater inland to the center of Antarctica. That would consume a monumental amount of energy, of course, but is technologically feasible.
- kube-system 4y agoAssuming that the center of Antarctica is still frozen after increasing energy consumption that much…
- jeffbee 4y agoWind or tidal power would be zero emissions and the most practical. You can use them directly without electrical conversion.
- Ebree 4y agoConsidering manufacturing, nothing is emissions free. Sea waves energy turbines are well engineered & safe for fauna not affecting water oxygenation unlike the other thing.
- high_pathetic 4y agoGreenland Ice Melt Today http://nsidc.org/greenland-today/ http://nsidc.org/greenland-today/
- Proven 4y ago
- Tyndale 4y agoThis is nonsense. Climate change isn't science because it's not falsifiable. Next.
- dapf 4y agoNo mention to this small detail in that article: https://www.sciencedaily.com/releases/2020/12/201207102105.htm https://www.sciencedaily.com/releases/2020/12/201207102105.h...