Blog Archive

Tuesday, April 24, 2018

Ben Santer, Charles Manski & Ray Weymann: Scientific American: Speaking Science to Power

A statement released by 317 [now at least 634] National Academy of Sciences members challenges the widespread dismissal of science and scientific understanding by the Trump administration

Speaking Science to Power

Credit: Jeff Greenberg Getty Images

by Ben Santer, Charles Manski, and Ray Weymann, Scientific American, April 23, 2018

Today, on April 23, 2018, a statement was released by 317 members of the U.S. National Academy of Sciences. It calls for “the Federal Government to maintain scientific content on publicly accessible websites, to appoint qualified personnel to positions requiring scientific expertise, to cease censorship and intimidation of Government scientists, and to reverse the decision to withdraw the United States from the Paris Accord.
We are the three writers and organizers of this statement. Although our expertise is in very different areas—economics, astrophysics and climate science—we share a common concern. It relates to the dismissal of science and scientific understanding by the current administration. This piece explains why we decided to write the statement, what we hope to accomplish with its release, and how interested readers can help to achieve the goals quoted above.  
Today’s statement had its genesis in an open letter by members of the National Academy of Sciences published in September 2016. The open letter warned of the potentially serious negative consequences of a U.S. withdrawal from the Paris climate accord, an action called for by then-candidate Donald J. Trump.

In the aftermath of the last U.S. presidential election, many of the negative consequences mentioned in the September 2016 open letter are now unfolding. The Trump administration has initiated the process of U.S. withdrawal from the Paris Agreement, and continues to cast doubt on the reality and seriousness of human-caused climate change. Negative consequences are now affecting many areas of science—not just climate science. The administration has shown a systematic disregard for using sound scientific information in public policy making. Science inconsistent with the administration’s ideological goals is ignored, suppressed, portrayed as too uncertain, and dismissed as politically and financially motivated.
This systematic disregard for science prompted our efforts to develop today’s new statement. We strongly believe that there is no future in ignorance. The United States does not benefit if it kicks the problem of human-caused climate change down the road, if it ignores sensible energy policies or if it regards access to clean air and clean water as a privilege of the few.
The ability to perform research and advance scientific understanding is not an inalienable right, given to us in perpetuity by virtue of the accident of our birthplace. Powerful forces in the current administration seek to constrain our understanding of the world, and how and why it is changing. Such forces of unreason are emboldened if they encounter inaction and silence; they thrive if scientific myths, misconceptions and disinformation are repeated without being challenged.
The statement we and our NAS colleagues issued today is an attempt to move beyond inaction and silence. Its message is clear: “Ignore science at your peril.” Perhaps the administration will pay no heed to this message; perhaps the message will be lost in the daily background noise of political events. Even if the administration is not listening, there is still value in warning publicly about the consequences of living in a country that pursues an anti-science agenda. We believe that millions of U.S. citizens are listening to this warning, and share our concern about the kind of country we are passing on to future generations.
Scientists have special responsibilities to inform the public on key societal issues that are relevant to their specific expertise. We are doing that today. But scientists are only a small part of the overall effort to rebut ignorance. Each of us has the ability to change our society for the better.

There are many creative ways of catalyzing change. We can seek reliable information on complex scientific issues, drawing on sources like the National Academy of Sciences, the U.S. National Climate AssessmentScientific American and government agencies. We can share that information with our colleagues, friends, family and neighbors, through conversation, letters to newspapers, and social media. We can encourage quality science education in our public schools, and ensure that science is taught accurately. We can support organizations advocating for the importance of science in society. We can become involved in the political process, and elect representatives who understand the value of science.

We live in a complex world. We face many existential problems: climate change, pandemics, terrorism, the threat of nuclear war, and diminishing food and water security. How we deal with these issues will shape the well-being of many future generations. The statement issued today is a reminder that ignorance is a poor strategy for solving complex challenges. We all lose if science is excluded from government. We hope you help us to share this message widely.

The views expressed are those of the author(s) and are not necessarily those of Scientific American.

Ben Santer, Charles Manski and Ray Weymann

Ben Santer is an atmospheric scientist and member of the U.S. National Academy of Sciences. Charles Manski is Board of Trustees Professor of Economics at Northwestern University and a member of the National Academy of Sciences. His most recent book is Public Policy in an Uncertain World (Harvard, 2013). Ray Weymann is director emeritus of the Carnegie Observatories and has done research in cosmology and on the intergalactic gas. Since retirement he has concentrated on public education regarding climate change.

Saturday, April 7, 2018

Algae, Impurities Darken Greenland Ice Sheet And Increases Melting

by Keith Cowing, SpaceRef, April 4, 2018

Impure Ice at Jakobshavn Isbrae on western Greenland. ©MODIS/NASA
The Dark Zone of Greenland ice sheet is a large continuous region on the western flank of the ice sheet; it is some 400 kilometers wide stretching about 100 kilometres up from the margin of the ice.
Some previous theories have attributed this darkening to water on top of the ice sheet - often seen as strikingly sapphire blue ponds, rivers and lakes. But a new study in Nature Communications provides a new hypothesis based on the character of the impurities on the ice surface itself.
"What we show is that the Dark Zone is covered in a finely distributed layer of dust, and black carbon, which provide nutrition for dark coloured algae. These are the main cause of the darkening," says professor Alun Hubbard, the co-author of the study and professor at CAGE (the Centre for Arctic Gas Hydrate, Environment and Climate at UiT, The Arctic University of Norway).
A dirt belt in the melt zone
The Dark Zone is literally a dirty belt of the melting area - the ablation zone - of the ice sheet. The darker this ablation zone is, the more of the sun's energy it absorbs, and the faster the ice melts.
Albedo is a measure of the reflectance of the ice sheet. It is the major factor governing how much incoming solar radiation is used to melt the ice and is the main positive feedback in Arctic climate change. Bright white surfaces, like snow or pure ice, reflect the sun's energy, but dark surfaces absorb it.
"The fact that a large portion of the western flank of the Greenland ice sheet has become dark means that the melt is up to five times as much as if it was a brilliant snow surface. " says Hubbard.
Algae - a major player
The ice algae seem to be one of the major players in this scheme - even the slight increase of the atmospheric temperature and liquid water production seems to promote algae colonization across the ice surface.
"The algae need nutrients and food, essentially dust, organic carbon, and water. In summer, these are plentiful and the algal bloom takes off. Because algae are dark in colour - they reinforce the dark zone. Thereby you get a positive feedback effect where the ice sheet absorbs even more solar radiation producing yet more melt."
Innovative drone study
The Dark Zone of the Greenland ice sheet is vast and previously observed by satellites such as MODIS. But for this study the scientists employed relatively modest drones - or unmanned aerial vehicles (UAV) - to survey the darkened ice belt in unprecedented detail.
While satellite data are great for the big picture of what's happening across the entire Greenland ice sheet, they only work at really coarse pixel resolutions.
"If we compare it to camera pixels, even the best satellites for the ice sheet imaging have resolution of tens of metres. They can't see the detail of what's happening on the ground. Our fixed-wing UAVs can take hundreds of images with pixel resolutions on the centimeter scale with an operating range of hundreds of kilometres," says Hubbard.
Scientists could see in real detail what the dark zone is made up of. In effect, this UAV survey across the ablation zone of the ice sheet perfectly bridges the gap between people on the ground studying what's under their feet in just one part of the ice sheet, and the satellite data that shows what's going on across the entire ice sheet.
"The UAV survey, with its amazing detail, allows us to identify and characterize all the different surface types and impurities across the entire dark zone, not just a small local little part of it."
The AUV images used in this study were collected by Johnny Ryan (Aberystwyth University, Brown University, University of California), Jason Box (GEUS) and Alun Hubbard (Aberystwyth University/CAGE) in the summer of 2014.
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