Published by Brunsell on 28 Feb 2009
Will, Arctic Ice, and Global Warming
Over the past few weeks, George Will has written two opinion pieces in the Washinton Post lambasting Global Warming alarmists. At its core, the controversy surrounds Will’s claims that arctic ice is about the same as it was in 1979.
By George F. Will, Washington Post
Friday, February 27, 2009; A17Citing data from the University of Illinois’ Arctic Climate Research Center, as interpreted on Jan. 1 by Daily Tech, a technology and science news blog, the column said that since September “the increase in sea ice has been the fastest change, either up or down, since 1979, when satellite record-keeping began.” According to the center, global sea ice levels at the end of 2008 were “near or slightly lower than” those of 1979. The center generally does not make its statistics available, but in a Jan. 12 statement the center confirmed that global sea ice levels were within a difference of less than 3 percent of the 1980 level.
This statement plays on a common theme amongst most climate change naysayers. A scientist makes a short-term climate prediction that doesn’t come true, so therefore climate change must be wrong. This year, one scientist predicted that 2008 may be the first that we have NO arctic ice. He was wrong…so Global Warming nay-sayers now say that man made global warming must be wrong (I find it failry disturbing that they celebrate their ignorance with a picture of a polar bear jumping from one piece of ice to another).
What George Will fails to include is that this year’s fall increase was predictable - it always increases in the fall. What is important to focus on is the minima for ice covereage. We still had arctic ice this year. In fact, it wasn’t even the lowest ice level on record. It was the second lowest since 1979. The lowest was during 2007. The third lowest was 2005. Over the last 30 years, the ice cover is trending downwards, with three of the the last four years being the worst on record. Trends are more important than looking at a single year because there are other influences (like increased cloud cover, which reflects sunlight and therefore has a cooling effect) that have short-term impacts.
NSIDC Research Scientist Julienne Stroeve said, “I find it incredible that we came so close to beating the 2007 record—without the especially warm and clear conditions we saw last summer. I hate to think what 2008 might have looked like if weather patterns had set up in a more extreme way (source). ”
seaice_2008_climatology_lr.mov
So, why did ice form at such a fast rate this year? In the fall, atmospheric conditions in the arctic quickly fall below freezing. In order for ocean ice to form, ocean water must release energy into the atmosphere to cool off. This causes an increase in near-surface atmospheric temperature (still below freezing) as the ocean cools and ice forms. This is anti-intuitive. Ice formation occurs as the near-surface temperature increases. When there is less ice cover, more water is exposed. More water exposure leads to a faster transfer of energy between the ocean and atmosphere. A faster transfer of energy leads to a higher rate of ice formation.
It is also important to note that 2008 marked the largest loss of ice ever recorded.
However, if we look at the total extent of ice lost between the March maximum and the September minimum, 2008 set a new record for total ice loss over an entire melt season.
2007 had the lowest recorded arctic ice level since 1979. This left a greater expanse of open water, which lead to a larger region of thin ice. Not surprisingly, thin ice disappears faster than thick ice (source). This will happen again in 2009 as thicker multi-year ice is replaced by thin single-year ice.
Figure 4 shows an animation of ice age in the Arctic from 1981 through 2007. The colors indicate the age of the sea ice in years; light blue is open water (OW). Areas in red are locations where the ice is five years or older, whereas the dark blue areas are first-year ice. The overall reduction in ice age over the past twenty-six years becomes evident as the animation runs through the years. The animation also shows seasonal variations in the ice cover as the first-year ice melts in the summer and regrows in the winter (source).
