Research & Commentary: The Cryosphere
One of the most common claims made by those who warn of an anthropogenic global warming crisis is that increases in temperature have led to unusual melting in mountain glaciers, Arctic sea ice, and polar icecaps. Known collectively as the cryosphere, these are areas on or near Earth’s surface so cold that water is present in solid form as snow or ice in glaciers, icecaps, and sea ice.
A report from the Nongovernmental International Panel on Climate Change (NIPCC), an independent group of some 50 scientists from 15 countries, titled Climate Change Reconsidered II: Physical Science, summarizes the large, significant body of research examining the effect of global warming on the cryosphere. The research shows changes in glacier and sea-ice extent occur in ways that frequently contradict and rarely concur with the claims of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) and the projections of its climate models.
Although the NIPCC report finds some melting of mountain glaciers, it notes melting is not occurring in other areas of the cryosphere. The current state of Arctic sea ice and polar icecaps is not “unnatural” and does not constitute evidence of a human impact on climate.
Information on the global ice budget collected from satellite and airborne resources, methods that are still in the early stages of development, suggest both the Greenland and Antarctic Ice Caps are close to balance. The global extent of sea-ice cover remains similar to what it was at the start of satellite observations in 1979, with ice shrinkage in the Arctic Ocean being offset by growth around Antarctica.
Contrary to claims by the IPCC, the research examined by NIPCC finds changes in the cryosphere occur in natural multidecadal, centennial, and millennial time-scale cycles independent of any human-related carbon dioxide (CO2) emissions. Historically, glaciers have been both considerably larger and substantially smaller than they are today; over the past 25,000 years, glaciers around the world have fluctuated widely in concert with changing climate, at times shrinking to positions and volumes smaller than today.
Although shrinking mountain glaciers make for popular propaganda videos, one mountain glacier is not indicative of the climate as a whole, and they do not respond to global temperature change in a simple, uniform way. Recent research indicates the observed changes in temperature, snowfall, ice flow speed, glacial extent, and iceberg calving in both Greenland and Antarctica lie within the limits of natural climate variation.
CCR-II concludes new research finds less melting of ice in the Arctic, Antarctic, and mountain glaciers than previously feared, and no melting at all that could be uniquely attributed to rising carbon dioxide levels.
The above introduction is based on text from Climate Change Reconsidered II: Physical Science and its Summary for Policymakers, published by The Heartland Institute for the Nongovernmental International Panel on Climate Change (NIPCC).
The following documents provide additional information about the cryosphere.
Chapter 5 of Climate Change Reconsidered II
Donald Easterbrook, Clifford Ollier, and Robert Carter summarize the extensive scientific literature on global warming as it might affect the cryosphere. The authors find changes in glacier and sea-ice extent occur in ways that frequently contradict and rarely concur with the claims of the IPCC and the projections of its climate models.
Summary for Policymakers of Climate Change Reconsidered II
The IPCC claims to know, apparently with rising certainty over time, that “most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations” (IPCC AR4 SPM, p. 10). This Summary for Policymakers summarizes and interprets Climate Change Reconsidered II, a major scientific report that refutes the IPCC’s claim.
Polar Sea Ice Exceeds the Long-Term Average
In this May 24, 2013 article for The Heartlander digital magazine, James M. Taylor reports polar sea ice remains more extensive than the long-term average, as has been the case for most of this year. Satellite instruments have precisely measured polar sea ice extent since 1979, producing a 33-year record of objective data.
Antarctic Sea Ice Sets More Records
In this March 15, 2013 article for The Heartlander digital magazine, James M. Taylor notes Antarctic sea ice extent has set several records this year: “So far during 2013, Antarctic sea ice extent has set records on eight separate dates, including the past five days in a row. By comparison, there are only seven dates in the entire calendar year when the greatest extent of Antarctic sea ice occurred before 2000.”
Monthly Antarctic, Arctic and Global Sea Ice Extent Since November 1978, after National Snow and Ice Data Center
This Web site tracks changes in sea ice across the globe since 1978.
Recent Ice-Sheet Growth in the Interior of Greenland
In this paper published in 2005 in Science, Ola M. Johannessen, Kirill Khvorostovsky, Martin W. Miles, and Leonid P. Bobylev analyze a continuous dataset of Greenland Ice Sheet altimeter height from European Remote Sensing satellites (ERS-1 and ERS-2), 1992 to 2003. An increase of 6.4 ± 0.2 centimeters per year (cm/year) is found in the vast interior areas above 1500 meters, in contrast to previous reports of high elevation balance.
The Phase Relations among Atmospheric CO2 Content, Temperature and Global Ice Volume Over the Past 420 ka
Writing in Quaternary Science Reviews in 2001, Manfred Mudelsee addresses the problem of determining the accuracy of estimates of the phase relations between Vostok’s CO2 and proxy air-temperature and ice-volume records for the past 420 ka. Over the full 420 ka of the Vostok record, he found CO2 variations lagged behind atmospheric temperature changes in the Southern Hemisphere by 1.3 ± 1.0 ka, and preceded global ice-volume variations by 2.7 ± 1.3 ka. Significant short-term changes in the lag of CO2 relative to temperature, subsequent to Terminations II and III, were also detected.
Overview and Assessment of Antarctic Ice-Sheet Mass Balance Estimates: 1992–2009
Zwally and Giovinetto compare the mass balance estimates of the Antarctic Ice Sheet (AIS) predicted in the 2007 report of the Intergovernmental Panel on Climate Change, as well as estimates in more recent reports, to real world numbers. In an attempt to determine which set of observations is most correct, the authors “compare the various estimates, discuss the methodology used, and critically assess the results,” and “modify the IOM estimate using (1) an alternate extrapolation to estimate the discharge from the non-observed 15% of the periphery, and (2) substitution of input from a field data compilation for input from an atmospheric model in 6% of the area.” Zwally and Giovinetto state “although recent reports of large and increasing rates of mass loss with time from GRACE-based studies cite agreement with IOM results,” they say the evidence “does not support that conclusion.”
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