Friday, December 19, 2008

Some highlights of 2008 climate change science

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Some highlights of 2008 climate change science

The amount information now generated by scientific efforts to comprehend climate change can make it difficult to feel like you’re keeping up. But as 2008 draws to a close I think it is worth looking back at some of the year’s highlights.

Toward that end I checked in this week with Don Wuebbles, who is a professor of atmospheric sciences at the University of Illinois and a lead author on the first two international assessments of climate change sponsored by the United Nations. Recognizing the continued, vociferous attempts to sow confusion by interest groups opposed to changes in public policy, Wuebbles emphasized that ongoing research substantiates the idea that the earth’s climate is changing significantly, and that that change is being driven by human activity.

The most dramatic aspect of the climate change story this year was the retreat of sea ice in the artic. Since 1979 scientists have been using satellites to measure the extent of arctic sea ice, and they use the minimum area it occupies in September as a benchmark for making comparisons among years. This year’s minimum was the second lowest recorded since satellite measurements began, following the record low set last year, and it was 34 percent lower than the average over the past three decades. [For short accounts see Sept. 17 NY Times article by Andy Revkin and Oct. 3 article from ScienceDaily. For much more information and cool animations of polar sea ice see "The Cryosphere Today" by William Chapman and others with the U of I Department of Atmospheric Sciences Polar Research Group.] At one point this summer both the Northwest Passage over Canada and the Northern Sea Route over Russia were open at the same time. The continued decline of ice in the arctic served to underscore the importance of designating polar bears as a threatened species, which U.S. Fish and Wildlife Service did this past March after years of footdragging.

Another dramatic ice story comes from Greenland, where the focus of attention is on how fast the Greenland ice sheet is melting, and how that melting will affect sea level over the next century. The most recent estimates used by the Intergovernmental Panel on Climate Change projected that the melting of Greenland ice would contribute between one and four inches to sea level rise over the next 100 years. But a study published this summer led by a University of Wisconsin geologist suggests that projection is too conservative, and that melting Greenland ice could contribute between one and two feet to sea level over 100 years. [ScienceDaily short versionNature Geoscience long version (requires access through library or subscription).] This projection is based on analysis of how the last great ice mass to cover parts of Canada and the U.S. melted under conditions similar to those expected for Greenland in the century to come.

Closer to home, professor Wuebbles collaborated with a former student as lead authors on the climate science component of the report, Climate Change and Chicago issued in September. That report projects that by the year 2100 summers in Chicago will resemble present-day summers in Atlanta, even assuming that the global economy make dramatic moves away from fossil fuels. Even hotter conditions are projected under a business-as-usual scenario, with as many as 80 summer days with temperatures above 90 degrees, as opposed to the current average of 15. Unfortunately winters are not projected to be so much warmer. The Chicago climate report also projects disruptive changes in precipitation patterns, with increased precipitation and greater storm events occurring in winter and spring, but less rainfall when it is most needed, later in the growing season.

The good news evident in Chicago’s Climate Action Plan is that it is possible for scientists, policymakers, and stakeholders to work together to confront the challenges posed by climate change. Perhaps there’s hope for such progress at the national level in the year to come.

Thursday, December 11, 2008

An environmental book list for the holidays

An environmental book list for the holidays

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As I put together Environmental Almanac from week to week I have the opportunity to interact with many thoughtful, generous people who are motivated by a wide range of environmental interests. For this week’s column, I asked some of them for thoughts on a list of books that readers might want to give as gifts or add to their own reading lists.

Judy Miller, environmental program manager with the Urbana Park District suggested two books that highlight a child’s perspective on the natural world: Winnie the Pooh by A.A. Milne “because it is just plain fun to read and the perfect example of how a four-year-old thinks and interacts with nature,” and A Sense of Wonder by Rachel Carson, which Miller said, “reminds us what it is like to be a child experiencing nature for the first time.”

Robert McKim, a philosopher and head of the UI Department of Religion, recommended Daniel Quinn's 1992 novel, Ishmael. McKim called “Ishmael” “challenging, thought-provoking, wise, not at all heavy-handed, and a really enjoyable read.” Further, he noted, “It raises important questions about how we ought to think of our relationship to the other species with whom we share this planet.”

Jamie Ellis, a botanist with the Illinois Natural History Survey and board president of Grand Prairie Friends, suggested a work of nonfiction, Heartsblood: Hunting, Spirituality and Wildness in America. This book, by David Petersen, a takes a critical look at hunting today. Ellis said, “I feel that hunting brings me closer to the nature I want to protect and conserve, and this book provides the philosophy and thought behind my feelings about hunting.”

The staff at Prairie Rivers Network collaborated to recommend The Secret Knowledge of Water: Discovering the Essence of the American Desert by Craig Childs, which they describe as “an adventurous and poetic journal of a back-country guide’s treks through the water-shaped desert.” They also suggested, Staying Put: Settling Down in a Restless World, by Indiana writer Scott Russell Sanders,” which is concerned with the importance of putting down roots and of attachments to specific places.

Chris Phillips, a herpetologist with the Illinois Natural History Survey and UI faculty affiliate, suggested two books about the work of biologists in the field: Mean and Lowly Things: Snakes, Science, and Survival in the Congo, by contemporary herpetologist, Kate Jackson, and Into the Jungle: Great Adventures in the Search for Evolution, which tells the stories of earlier naturalists whose work provided the foundation for our scientific understanding of life on earth.

Cynthia Hoyle, a transportation planning consultant with the Champaign-Urbana Mass Transit District recommended Edens Lost & Found: How Ordinary Citizens are Restoring Our Great American Cities, by Harry Wiland and Dale Bell. This book, which is a companion to a PBS series available on DVD, tells the inspiring stories of how ordinary people have worked together to heal the Earth and bring hope and opportunity to our inner cities by uncovering and restoring the beauty of nature.

May Berenbaum, head of the UI Department of Entomology, and a leader in the ongoing, international effort to understand dramatic declines in honey bees, recommended a new book on that topic by Rowan Jacobsen called Fruitless Fall: The Collapse of the Honey Bee and the Coming Agricultural Crisis.

Finally, if you could use a break from shopping and reading you might want to check out Hotspots, a new film that will air on public television nextweek. It provides a global perspective on the current wave of plant and animal extinction, so it won’t be a pick-me-up, but it promises a view that includes hope for the future.

Thursday, December 04, 2008

Beavers in the Prairie State

Beavers in the Prairie State

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On a recent walk at River Bend Forest Preserve someone I met on the trail asked if I knew a good place in Illinois to see beavers. After a moment’s thought I answered, “Anywhere,” because there are unmistakable signs of them in so many places. Beaver-chewed trees, sticks stripped of bark and the slides beavers create by dragging branches down the bank are just part of the landscape along many bodies of water in the Prairie State. [Photo: Chewed trees, like this oak on the bank of the Sangamon River at Lodge Park in Piatt County, are an unmistakable sign of beaver activity.]

Looking back, though, I realized that my quick answer didn’t really get the questioner any closer to laying eyes on Illinois’ largest rodent. That’s because even though beavers live throughout the state, they are not often seen, since they are most active at night, or near dusk and dawn. My answer really should have been to say that if you want to see beavers your best bet is to find a site on a stream or pond where they’ve been active and quietly watch it in the hour before sunset.

There was a time in the not-too-distant past when it was difficult to find beavers in Illinois at all, since prior to 1900 they were nearly extirpated from the state by unregulated trapping. They bounced back over the course of the twentieth century through a combination of protection and reintroduction, and are now common where suitable habitat exists. Indeed, today, beavers sometimes prove a significant nuisance when their ideas about suitable locations for ponds conflict with ours.

Of course, some humans admire the ingenious ways beavers modify their environment, and their ability to do this also benefits the many plants and animals that make use of wetlands. For beavers, the point of building dams is to create ponds that are deep enough not to freeze solid in winter. This allows them to construct lodges that are accessible only through underwater passages. The typical beaver lodge is a dome-shaped mound made of sticks, logs and mud, and a really big one may be 10 feet tall and 30 feet around. But many perfectly respectable beavers live in burrows excavated in the banks of bodies of water, too. That’s why you may find all of the other evidence that beavers inhabit a pond or stretch of river without ever seeing a lodge. Bank burrows, like lodges, provide beavers with protection from weather and predators.

Beavers possess an array of physical adaptations that suit them for a semi-aquatic life. They propel themselves through the water with webbed hind feet, using their signature, paddle-shaped tail as a rudder. Their eyes are protected by a clear, third eyelid, and their nostrils and ears can be closed when they submerge. A beaver may remain underwater for as long as 15 minutes at a stretch.

Unlike most other mammals, beavers are monogamous, and male and female beaver mates remain together until one of the pair dies. Beaver young live with their parents for nearly two years, so family groups include adults, yearlings and kits together.

If you would like to learn more about beavers or any of the other 59 species of wild mammals that occur regularly in Illinois, I would encourage you to pick up a copy of the Field Manual of Illinois Mammals published this year by the Illinois Natural History Survey. The manual contains all of the information you could ask for in such a book, but it is written with attention to the interests of readers who are not scientists, and it is distinguished by first-rate photographs and original color drawings.