Originally Posted by
N2264J
What your cartoon doesn't show very well is the loss of 278,000 square miles
of ice since 1979 (roughly the size of Texas). Also, it doesn't show the ice
sheet over the arctic getting thinner.
The arctic has been referred to as the canary in the mindshaft, in part
because it represents one of the dozens of feedback systems that act like
a self sustaining engine to exacerbate the problem ie the ice sheet reflects
the sun's rays back out into space - as ice is melted in the summer months,
it exposes sea water that absorbs the heat to melt adjacent ice, exposing
more ocean that is warmed and thereby melting more ice, etcetera.
The world's oceans are a natural carbon sink. Due to the increase of
carbon in the atmosphere that is being absorbed, the ocean's pH are
decreasing becoming more acidic. Acidic enough, in fact, to start
dissolving coral and shellfish shells.
Suffice it to say, the planet will no longer be able to support the current
number of human beings when the oceans start dying.
There's a difference between climate and weather. The Flat-earthers tend
to get wrapped around the axle about local weather and miss the big picture:
"It snowed in Houston this year so global warming must be a hoax." I'm starting
to think the denial is a defense mechanism to suppress panic.
This is worth going over at length as your post brings up some issues that need to be addressed.
Take a look at this:
The maximum extent of the sea ice varies each year, but it is fair to say that it is at least 13 million square km. The summertime minimum sea ice varies as well, but one can say that the min is not more than 7 million square km. Texas is just under 700,000 square kilometers--that means that an area equal to at least 10 Texases melts every year. An area equal to 10 Texases also refreezes every year. I am guessing (since you provide no references)that the Texas size lost ice to which you referred is from the 2007 minimum. Predictions of an "ice free arctic" are simple extrapolations based on the 2007 trend--these extrapolations are neutered by the higher 2008, and the much higher 2009 minima.
The warming feedback from reduced albedo is a well-known phenomenon but, if it was as simple as you say there would be runaway warming every spring. If it was as well understood as you imply, somebody would have predicted the ice recovery the last two summers. I am unaware of such a prediction.
Although you don't say it explicitly, I get the impression that your view of the arctic sea ice as a vast area that is permanently and unbrokenly frozen. The area described by the graphs in this post, and in the cartoon you liked is the area where there is more than 15% sea ice coverage. It is not one big piece of ice that has been there since the last ice age. It is an area of sea ice coverage, the majority of which melts every summer and refreezes in the winter months.
It was a cold summer in the northern hemisphere and it will be a cold winter. The arctic sea ice extent at its minimum in 2010 will be higher again than in 2009. Call me out next Sept if I am wrong.
WW