To: Wharf Rat who wrote (41571 ) 7/27/2013 1:11:04 AM From: Bilow 2 RecommendationsRecommended By
Read Replies (1) | Respond to Hi Rat; As published by the American Geological Institute in September 2006, in their journal Geotimes (which has since been renamed "EARTH!"):Testing Global Warming Hypotheses Global climate change has been a natural phenomenon driven by natural processes for 4.5 billion years. Nevertheless, cultural pressures exist to identify a human cause for current global climate change.Michael Mann and colleagues, the hockey stick study — which statistically interpreted tree ring data as demonstrating unprecedented current warming relative to the past 1,000 years — failed to capture and denied the existence of the “medieval climate optimum,” a warming event beginning 1,100 years ago. The hockey stick was the basis for the U.N. Intergovernmental Panel on Climate Change’s statement that “there is discernible human impact on climate.” Vindicating the original criticism of past-published researchers, the National Academy report identifies the failure of the hockey stick to model climate beyond the past 400 years, as evidenced by its inability to reflect the medieval climate optimum. The optimum has been extensively documented by recorded human history and proxies, but cannot be explained by computer models based on equations that assume that greenhouse gases dominate climate change. These same models predict massive increases in Earth’s atmospheric temperature because of the additions of a small percentage of human-derived carbon dioxide.... It is incumbent on the geoscience profession to better communicate this fundamental principle. Statements that the Arctic is warming, or that ice is melting, or that summer temperatures are higher can each be true, but they do not imply any specific cause of such changes . Some in the media, government and even academic organizations follow those statements with, “so that proves that humans are causing climate change.” But that statement does not follow and is not true. ... Despite this pattern, many people will argue that a significant portion of the modern temperature rise is due to human greenhouse gas emissions. Yet the human contribution to total global greenhouse gases is so small as to be de minimis. The sum of these observations and correlations falsify the hypothesis that human additions to greenhouse gases are a significant climate driver. ... agiweb.org
