Lying with statistics, or in this case lying with graphs. The National Climate Assessment (NCA) wants us to believe that Greenland and Antarctica are rapidly losing ice. They use these graphs to make that case:
Wow, I bet you think Greenland and Antarctica will be cultivating fields and exporting corn any day now. No, the ice sheets in those places actually aren’t going anywhere, at least not for the next several thousand years if current trends continue. You see, the graphs above are not proportional. They depict ice loss in raw numbers.
Say I had 10,000 marbles and I lose about one a year. Not a big deal. It will take me 100 years at that rate to lose 1% of my marbles. Now say I lose one marble every 22 years. At that rate it will take me 2,200 years to lose 1% of my marbles.
If I constructed a graph showing the number of marbles I’ve lost over a ten year period and did it so as to contrast the total marbles lost after 10 years to the total number lost after the first year, I’d get a steeply sloping line from left to right which would make it appear that I was losing my marbles at an alarming rate. But that would be misleading and would erroneously give the impression that I’m losing my marbles at a much faster rate than I really am losing my marbles. That’s the trick the NSA is using to try to make us us lose all of our marbles and believe that Greenland and Antarctica are losing ice at a rapid rate when in reality they are losing ice at a rate slower than a snail could crawl from Greenland to Antarctica.
These two examples depict the exact rate at which Greenland and Antarctica are losing ice, respectively. Greenland is losing 0.01% of its ice per year and Antarctica is losing 4.5/10,000ths of 1 percent per year. It will take Greenland a century to lose 1% of its ice, and it will take Antarctica 2,200 years to lose 1% of its ice.
These graphs are based on the proportional context of the loss of ice over the 10-year period 2003-2012 and depict a line that is almost straight for Greenland and even straighter for Antarctica. The NCA couldn’t use these graphs because then no one would think the ice loss is rapid, because it isn’t.
The first graph is from the NCA. The source for the amount of ice loss of Greenland and Antarctica and the second and third graphs are E. Calvin Beisner and J.C. Keister at the Watts Up With That? blog.
The current rate of ice loss will likely change. At times it may be greater than at present, at other times it will likely be slower, or one or both places may be increasing its ice sheet. At any rate, there is simply no reason to believe that the total amount of ice on Greenland or Antarctica is going to change much at all within any amount of time relevant to the next few hundred human generations.