How much of Greenland's ice melted during past periods of global warming? Two first-of-their-kind studies in Nature look much deeper into the history of Greenland than previous techniques allowed. One of the studies, led by University of Vermont geologist Paul Bierman, concludes that East Greenland -- like the coastal scene shown in this image from near Tasiilaq -- has been actively scoured by glacial ice for much of the last 7.5 million years. The other study presents contrasting results suggesting the disappearance of the ice sheet over the center of Greenland during at least some of the Pleistocene. The two studies improve our understand of Greenland's deep past, while raising questions about both the past and future of its giant ice sheet in a changing climate. CREDIT Joshua Brown/UVM

Studies worry: Is Greenland on thin ice?

From the UNIVERSITY OF VERMONT Greenland on thin ice? Two studies in Nature open deep history of Greenland’s ice sheet — and raise new questions about its stability The ice sheet covering Greenland is four times bigger than California — and holds enough water to raise global sea-level more than twenty feet if most of it…

Photo: Martin Koser of Denmark

Study: The climate ‘uncertainty monster’ limits geoengineering schemes

From the VTT TECHNICAL RESEARCH CENTRE OF FINLAND, a paper that suggests Dr. Judith Curry’s view of the “uncertainty monster” was right all along. Uncertainties related to climate engineering limit its use in curbing climate change Climate engineering refers to the systematic, large-scale modification of the environment using various climate intervention techniques. However, a new study…

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How SkepticalScience views global warming – one way only

Guest essay by Sheldon Walker Most people have probably seen the SkepticalScience graph called “The Escalator”. If you haven’t seen it yet, then you can view it here: Source: http://www.skepticalscience.com/graphics.php?g=47 SkepticalScience claims that “Contrarians” inappropriately “cherrypick” short time periods that show a cooling trend. But SkepticalScience uses a linear regression over the full date range (1970…