NORMAN — In his November 10 Letter, Gary Reynolds misstated information in the October 27 op-ed by Catherine Hobbs, “New report says global warming is “unequivocal.” Mr. Reynolds incorrectly stated that Dr. Hobbs cited evidence from the 2007 UN Panel to assess climate change. Actually, Dr. Hobbs quoted directly from the report released in September, “Climate Change 2013: The Physical Science Basis, Summary for Policy Makers” from Working Group 1’s contribution to the Fifth Assessment Report by the UN Intergovernmental Panel on Climate Change. The report states, “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.” We urge Mr. Reynolds to read the entire online report written by climate experts including over 600 lead authors and contributing authors, and 50 review editors from more than 39 countries. The authors considered evidence from peer-reviewed journals up to March 2013.
Citing only an unnamed “chief meteorologist for NASA” as a source of information, Mr. Reynolds made statements about Arctic and Antarctic sea ice that contradict information on the NASA website. The volume and extent of Arctic sea ice decreases every summer, and the magnitude of the decrease has been increasing over the last few decades. According to the NASA website, the extent of Arctic sea ice reached its 2013 summer minimum at a level higher than last year’s record low level, but it is “still the sixth lowest extent of the satellite record . . .” NASA states further that this “is in line with the long-term downward trend of about 12 percent per decade since the late 1970s.” NASA glaciologist, Walt Meier states, “I was expecting that this year would be higher than last year ... in our satellite data, the Arctic sea ice has never set record low minimums in consecutive years.”
Regarding the southern Antarctic sea ice, Mr. Reynolds mischaracterized the more complex effects of Antarctic climate. Unlike Arctic ice, which forms in an ocean basin hemmed in by continental masses, Antarctic sea ice freezes on the sea that encircles the Antarctica continent, and is much more susceptible to the effects of open ocean currents and winds. As a result, there is more variability depending on regional geography. On average, Antarctic sea ice is growing at about 1.5 percent per decade, mostly in the area of the Ross Ice Shelf, where winds are stronger and pushing ice further offshore. As NASA’s website explains, “Recent research points at the depleted ozone layer over Antarctica as a possible culprit. Ozone absorbs solar energy, so a lower concentration of this molecule can lead to a cooling of the stratosphere over Antarctica. At the same time, the temperate latitudes have been warming, and the differential in temperatures has strengthened the circumpolar winds flowing over the Ross Ice Shelf.” For the last two winters, winter sea ice extents were at record highs, but this increase is far less than the decrease in northern Arctic Ice. As NASA climate scientist, Claire Parkinson, states, “Climate does not change uniformly: The Earth is very large and the expectation definitely would be that there would be different changes in different regions of the world. That’s true even if overall the [climate] system is warming.”