Right Samwise. We are back to the level we were near the level the had in 2000 according to your graph. The text you quoted is slightly confusing though.
Any thoughts on my background climate data extrapolation?
Hiya John,
Can you point out the parts that are confusing or not clear?
I'm not sure what your point is about comparing now with 2000. At any given point in time, one can usually find a similar reading from the past; especially since, in this case, last year was a record breaker.
The important thing to look at is each trend line, the linear least squares regression.
I'm sure that with the more recent data, the trend lines will be a little less steep, but they're still pointing downward (increasing average ice-loss).
You know about the meaning of the "slope," right?
I recall some models predict a kind of decade-long 'tipping point' for the arctic ice related to the loss in albedo, etc. The models had predicted this would happen around mid-century.
However the recent behavior is paralleling what they had predicted for that mid-century 'tipping point.'
It'll be interesting, in a few years, to see if this decade-long tipping point has alreaday started so much earlier than predicted (falsifying the models, btw), or if this is just a minor fluctuation along the road to a blissfully moderate climate (or a climate that does sorta follow the IPCC projections). My greatest fear is that we'll trigger some sort of "cold mode," possibly precipitating a partial or even full glaciation.
Any thoughts on my background climate data extrapolation?
The thing with the 3 rough mid-points, and the 30 year cooling/warming cycling? Well, as you said,
"This little thought experiment of mine... This is a very poor sample... This is just 'back of an envelope' type of calculation.... guessing at the mid points and assuming that the mid points...."
It's hard to say whether the lack of agreement with the predictions is due to the fallicy of the thought experiment itself, or the roughness of the calculations (or both).
Or neither! I'm not sure if your ideas even relate to the predictions, but I'll look at it from beginnning to end again. It's an interesting 'thought experiment,' to divide up the different forcers.
My other thought was that maybe the two cooling periods that you mentioned were just interruptions in a long warming trend; cooling interruptions caused by Krakatoa, in 1883, and the huge increase in sulfate pollution that began with WWII and ended with 'cap & trade' of sulfates back in the 70's (to clean up acid rain).
http://wgntv.trb.com/news/weather/wgntv-weatherwords-v,0,2765479.story
Volcanic cooling: A decline of average global temperatures following volcanic eruptions. Global temperatures fell about one degree Fahrenheit in the few years following the eruptions of Krakatoa (between Sumatra and Java) in 1883 and Aging Volcano in Bali in 1963.
http://isbndb.com/d/book/learning_to_manage_global_environmental_risks_a04.html"In 1973 the first EC Environmental Action Program (EAP) was adopted."
"...efforts to deal with climate change, ozone depletion, and acid rain from 1957 (The International Geophysical Year) through 1992 (the UN Conference on Environment and Development)."
Well, just a thought....
