NOAA: Arctic Likely Free Of Summer Ice By 2050 — Possibly Much Sooner 335
Scientists from the National Oceanic and Atmospheric Administration have published research into the shrinking levels of sea ice in the Arctic. They wanted to figure out how long it would take before summer sea ice disappeared entirely. Since there's no perfect model for predicting ice levels, they used three different methods. All three predicted the Arctic would be nearly free of summer sea ice by the middle of the century, and one indicated it could happen as early as 2020. Two of the methods were based on observed sea ice trends. If ice loss proceeds as it has in the past decade, we get the 2020 timeframe. If ice loss events are large, like the 2007 and 2012 events, but happen at random some years, the estimate is pushed back to 2030. The third method uses global climate models to 'predict atmosphere, ocean, land, and sea ice conditions over time.' This model pushes the timeframe back to 2040 at the earliest, and around 2060 as the median (abstract). One of the study's authors, James Overland, said, "Rapid Arctic sea ice loss is probably the most visible indicator of global climate change; it leads to shifts in ecosystems and economic access, and potentially impacts weather throughout the northern hemisphere. Increased physical understanding of rapid Arctic climate shifts and improved models are needed that give a more detailed picture and timing of what to expect so we can better prepare and adapt to such changes. Early loss of Arctic sea ice gives immediacy to the issue of climate change."
Empirical curve fitting suggests sooner. (Score:5, Informative)
One approach looks only at ice volume measurements, and explicitly ignores theory because the existing theoretical models failed to predict anything like the ice loss that we observed. Using the simplest accelerating-curve-fit, we get first ice free in September 2017, and six months per year ice free by 2025.
http://earlywarn.blogspot.com/2012/08/more-on-arctic-sea-ice-volume.html [blogspot.com]
Re:Excellent! (Score:5, Informative)
I will be able to water ski from North America to Russia, always wanted to do this.
You already can. And Sarah Palin might even wave as you go by!
Seriously, check the map. You don't actually need to cross the Pole to reach Russia from Alaska.
Re:I thought this was over and done already? (Score:3, Informative)
Weather and climate are not the same thing. Just as you can't predict whether a given coin toss will end up heads or tails, but you can pretty accurately predict the results of 50 or 100 or 1000 coin tosses in ensemble.
Second, there isn't a whole of precision in those climate estimates, as they range from 2020 (7 years away) out to 2050 (30 years later).
Re:Let's ignore the fact that arctic ice is normal (Score:4, Informative)
Let's do only pick this one particular time when the ice is still below normal, but not by the much, and pretend like there's absolutely nothing going on. That's a winning strategy!
Take a look at the two year trend. At no point has it ever been at normal, much less above it, and many times it's been significantly below normal for significant periods of time. The trend is unmistakable.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png [uiuc.edu]
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png [uiuc.edu]
I'm not surprised that ice recovers in the winter when it's still quite cold. The Earth's tilt hasn't changed. The summer trends are unmistakable, though, and not be ignored.
Satellite data on ice mass [Re:Let's ignore th...] (Score:5, Informative)
The most unambiguious measurement of arctic ice at the moment is from the GRACE satellite (Gravity Recovery and Climate Experiment), a satellite that is measuring the mass of ice on the poles.
These results do not support your statement "the amount of multi-year ice is increasing." In fact, it is significantly decreasing
http://www.nasa.gov/mission_pages/Grace/news/grace20121129.html [nasa.gov]
http://www.nasa.gov/mission_pages/Grace/multimedia/chart20121129.html [nasa.gov] shows the graph.
Here's an animation showing specifically the data from Greenland: http://photojournal.jpl.nasa.gov/archive/PIA13955_Greenland_Ice_Loss_20111205-640.mov [nasa.gov]
Re:Hurry up damnit (Score:5, Informative)
Boy this was hard [wikipedia.org].
Or even harder [lmgtfy.com]
Re:Empirical curve fitting suggests sooner. (Score:4, Informative)
Here are more curves that were posted in the comments of the blog you're linking:
https://sites.google.com/site/arctischepinguin/home/piomas [google.com]
Clearly, the exponential model has the best fit (which is not very surprising), and says 2015, take or give 1 year for 95% confidence. Of course, there is no theoretical model behind, but most of the time, the theoretical explanation comes after the empirical fit.
Re:Or not... (Score:5, Informative)
I don't know about "long range", but the medium-range projections have almost always proven to be too optimistic.
I suspect IPCC feels political pressure to tone down the bad news.
Re:I thought this was over and done already? (Score:5, Informative)
Anti-firearm tends to correlate with urban more than conservative.
Re:Hurry up damnit (Score:2, Informative)
When you are using Wikipedia as a citation, you are either lazy, or you don't understand what Wikipedia is.
Re:I thought this was over and done already? (Score:4, Informative)
Nooo...it was because many of us that was for actually FIXING the problem saw the AGW platform hijacked by scammers [nakedcapitalism.com] who don't give a flying fuck about the climate or the planet, they just want to fleece you for themselves and their friends.
Then let's look at the evidence: firstly you say that in general, people on slashdot adopting a counter position do so because emissions reduction schemes (i.e cap and trade, emissions trading, direct legislation for reduction) are a scam. But they think the actual phenomenon of anthropogenic climate change is real:
This guy thinks the reduction in arctic sea ice is caused by underwater volcanoes: http://science.slashdot.org/comments.pl?sid=3645525&cid=43442631 [slashdot.org]. If he thinks that anthropogenic climate change is real, why is he saying that it is not? This seems disingenuous.
This guys seems to think that the predictions of climate science can't be trusted - although bizarrely, he posted a link which indicates otherwise: http://science.slashdot.org/comments.pl?sid=3645525&cid=43441341 [slashdot.org]. If he though those predictions could be trusted, why not say so? This seems disingenuous.
This guy thinks that the arctic ice is not melting at all: http://science.slashdot.org/comments.pl?sid=3645525&cid=43441403 [slashdot.org] - if he thinks that AGW is real (and evidenced by melting arctic ice) why did he not just say it? This seems disingenuous.
This guy thinks it's happened but won't get off his arse and do anything about it because it will mainly happen to poor people: http://science.slashdot.org/comments.pl?sid=3645525&cid=43443501 [slashdot.org]. If, he, as you claim, is genuinely concerned about climate change, why does he not just say so? This seems disingenuous.
Notably, these positions are all:
1. Notably lacking any hard evidence
2. In contradiciton with one another
As is yours.
Why is the true position?
Which out of the whole crowd of you is telling us the truth?