Arctic Sea Ice Minimum Volumes [Septembers] 1979-2014|
Volume (as opposed to surface area) loss, so thinning of ice as well as oscilating retreat of area are both factors:
The above shows the critical volume not surface area (see also here for area (extent) collapsing faster than previously estimated; also here)
2012 October UPDATE(above
was as of 8/25/12 as the graph above says), update of Oct 3rd, giving final end of melt season numbers, sadly,
even more extreme, we're at 3.3 not 3.6 for the latest annual
And, now: What what level is co2? And in the past? Two graphs, historical and present. Right now
Conclusion? By ~2015 peak annual global average Co2 levels (red line) will hit 400 ppm (parts per million), and by ~2016, which may coincidentally be when summer arctic ice is gone, even the average annual (seasonally adjusted, look at black line) global concentrations will be at about 400ppm. (and pushed higher each year by annual emissions)
Just a short few years ago, in 2010, it looked like this:
Now Look at the preceding 800,000 graph and find "400ppm" there. A massive spike of geologic proportions. And "[Corporate Capitalist, and Western and now Asian Industrial] Business As Usual doesn't stop there as 400ppm is zoomed by towards 425, 450, 500ppm, 600ppm and beyond by end of this century, possibly by mid-century. Again compare 400ppm and beyond with history:
In such a scenario, there could a "new class of heatwaves" of magnitudes never experienced before, says the report entitled Turn Down the Heat, Why A Four Degrees Celsius Warmer World Must Be Avoided. ..[the report is] synthesis of the latest climate science prepared by the Potsdam Institute for Climate Impact Research (PIK) and German NGO Climate Analytics for the World Bank. ..
"Current scientific evidence suggests that even with the current commitments and pledges fully implemented, there is roughly a 20 percent likelihood of exceeding 4 degrees C by 2100, and a 10 percent chance of 4 degrees C being exceeded as early as the 2070." ......However, "warming would not stop there," says the report. "Because of the slow response of the climate system, the greenhouse gas emissions and concentrations that would lead to warming of 4 degrees C by 2100 would actually commit the world to much higher warming, exceeding 6 degrees C or more, in the long term......
..writes Jim Yong Kim, president of the World Bank in the foreword. "A 4 degrees C world is likely to be one in which communities, cities and countries would experience severe disruptions, damage, and dislocation, with many of these risks spread unequally....so report should "shock us" into action....The biggest jump in warming would be expected to occur over land (range from 4 degrees C-10 degrees C). Increases of 6 degrees C or more in average monthly summer temperatures would be expected in the Mediterranean, North Africa, Middle East and parts of the USA "there is also no certainty that adaptation to a 4 degrees C world is [even] possible [if we get there, so we should make sure to NOT ever, ever get there]."
But even putting aside predictions about the future of Arctic ice collapse - just look at what's already happened and it's hard to avoid the conclusion that "collapse to a substantial extent" hasn't already happened. It's just not yet as complete a collapse as where we're unfortunately headed.