“The panel, however, has lowered predictions of how much sea levels will rise in comparison with its last report in 2001. Climate change sceptics are expected to seize on the revised figures as evidence that action to combat global warming is less urgent.” “UN downgrades man’s impact on the climate,” The Telgraph, January 12, 2006.
One of the strengths of the IPCC is that it tends to be very conservative and cautious in its predictions. Nevertheless, the report’s prediction that by 2100 the sea level will rise anywhere between 7 and 23 inches is hardly good news, especially in that sea level will keep rising for centuries more. Such a rise will mean serious economic, health and environmental damage to coastal areas.
IPCC’s projections of sea level rise are based on (1) the expansion of ocean waters as they warm, (2) the melting of mountain glaciers and ice caps, and (3) the accumulation and melting of snow on the surfaces of the Greenland and Antarctic ice sheets. However, because it is so hard to estimate, the IPCC’s projection specifically excludes the potential for large changes in the flow of the West Antarctic and Greenland ice sheets. To account for this omission, the IPCC report instead includes a proviso that sea level rise could be significantly greater (and so more damaging) if the deterioration of the big ice sheets accelerates.
And there are some early indications that this may be starting to happen. In 2002, Antarctica’s 1,255-square-mile Larsen B ice shelf broke off and disappeared in just 35 days and in 2006 an entire shelf also vanished in about a month because of global warming. Both events are illustrations that change which is much more rapid that can be accounted for in present models. As another indicate that the pace of melting, NASA satellite data indicate that Greenland is losing 53 cubic miles of ice each yeartwice the rate it was losing in 1996.
These and other recent findings have led climate experts around the world to predict that this century’s rise in sea level is likely to be, as NASA’s James Hansen has said, “measured in feet not inches.” And Hansen is not alone in his concern; in a recent issue of SCIENCE, Stefan Rahmstorf, a physics and oceanography professor from Potsdam University in Germany and a climate panel lead author extrapolated from recent trends, and projected that sea level would rise by 20 inches to 55 inches by 2100.
For More Information:
- http://www.sciencemag.org/cgi/content/summary/315/5810/297n?maxtoshow= &HITS=10&hits=10&RESULTFORMAT=&fulltext=%22sea+level+rise%22&searchid= 1&FIRSTINDEX=0&sortspec=date&resourcetype=HWCIT
Myth: There is a problem with the peer-review process in generaland since the argument has become so politicized, climatologists who disagree with the consensus may be afraid to speak out.
“Climate change has tended to be caught in a straightjacket between so-called ‘skeptics’ and so-called ‘alarmists’ with seemingly little room left in the middle for people who may have reasonable doubts or heterodox views about the range of policy descriptions that should be considered for climate change of uncertain dimensions.”
Steven F. Hayward and Kenneth Green, American Enterprise Institute, in “AEI Critiques of Warming Questioned,” Washington Post, February 5, 2007.
Peer-reviewed research is research that has been published in a scholarly scientific journal after review by an expert peer or peers from the authors’ same field. The process is undertaken to ensure that authors meet the standards of their discipline, and to establish the validity and accuracy of the research. With an occasional exception, the peer-review process generally works quite well.
Today’s widely-held views on global warming are based on literally thousands of peer-reviewed studies. The research contained in these studies is scrupulously vetted to guarantee that it is based on solid scientific evidence and methodology, and that the conclusions contained therein stand up to scientific scrutiny.
Climatologists who disagree with consensus views have little to fear from the peer-review process as long as that research conforms to scientific standards. In any event, the research of a few scientists who may hold dissenting viewswhether their research is published subject to peer-review or notat best will add only a small bit of information to a very large body of well-reviewed, established knowledge.
For More Information:
Myth: Since correlation does not imply causation, we should not assume that rising temperatures necessarily relate to increased greenhouse gas concentrations. For example, the IPCC does not explain away what is shown by data from ice-core samples, which show that the relationship between historic temperatures and CO2 levels has been that carbon dioxide increases follow a rise in temperature, rather than the other way around.
“Temperatures have risen and fallen significantly over the past two millennia with levels of greenhouse gases being static. The IPCC continues to blindly follow a single, unproven hypothesis and does not tolerate dissent.”
Martin Livermore, Britain’s Scientific Alliance, in “Through the Climate Window,” BBC, February 2, 2007.
It is true that ice core studies have shown that carbon dioxide starts to increase about 800 years after Antarctic temperature begins rising following the beginning of glacial terminationswarming periods at the ends of ice ages that have occurred about every 100,000 years, most likely as a result of orbital parameters favorable to this result.
However, a glacial terminationa period of change from cold glacial conditions to warmer interglacial conditionslasts about 5,000 years. Or about 4,200 more years after CO2 begins to increase.
While CO2 is not considered the cause of the first 800 years of warming, it certainly contributed to the ongoing warming over the remaining, on average, 4,200 years of warming. In other words, rising levels of CO2 are present in Antarctic ice core samples for about 80 percent of the warming years.
Under one possible scenario, the 800-year warming period cited above may trigger the release of deep ocean CO2 that had lain trapped under the ocean during the intense phases of the ice ages. Once released, that CO2 rises and begins to trap heat, further warming the Earth. That heat, in turn, causes the release of even more CO2, and so on, in a classic greenhouse gas scenario.
What does this mean for our situation today? Simply that a natural change in the CO2 concentration was not the initiator of our warming, not that CO2 injected by other means (i.e., combustion of fossil fuels) will not cause warming. In fact, the real concern is that the natural positive feedback process involving CO2 ejection from the ocean might further amplify the warming that humans have begun..