Scientists are simply unsure if climate change could have had anything to do with Hurricane Sandy, but there is plenty of other evidence about how global warming is changing nature as we know it and leaving no place on land or sea untouched.
Scientists from Oregon State University have found that some high mountain meadows — described as “unique ecosystems that once were carpeted with grasses, shrubs and wildflowers” — in the Pacific Northwest are in rapid decline as a result of climate change. Warmer temperatures have led to reduced snowpacks and longer growing seasons that have resulted in trees invading the meadows and threatening the biodiversity of their plant, animal and insect life.
The changes to the meadow ecosystem are occurring at high and low altitudes and in many areas of the American West, notes Harold Zald, a research associate in the College of Forestry at Oregon State University and lead author of this study which was published in Landscape Ecology. Zald and his colleagues studied a decades-long decline at Jefferson Park, a 333-acre subalpine meadow in the central Oregon Cascade Range that is at the base of a 10,497-foot volcano, Mt. Jefferson.
From 1950 to 2007, the researchers found that tree occupation went from 8 percent to 35 percent. The trees that have invaded the meadow are mountain hemlock trees. “Grassy balds,” meadows found at the tops of some lower elevation peaks in the Oregon Coast Range, have also declined an average of 50 percent between 1950 and 2000 at some sites.
Zald says that the changes to mountain meadows have been happening slowly over time. As temperatures on the earth have heated up, the growing season for the trees’ seedlings has been gradually extended and just a few extra months or even weeks greatly increases the chances of their survival. These changes occur bit by bit, just as the melting of glaciers and rising sea levels have.
Recently, scientists have alerted us as to how much faster these changes are occurring. Scientists have predicted that there could be no sea ice in the summer in a decade, sooner than expected. They also note that previous estimates of the rise of sea levels may be too low as earlier predictions did not take into account all the factors that contribute to this, as University of Colorado geologist Bill Hay recently said in a presentation on November 4 to the Geological Society of America in Charlotte, North Carolina, USA.
Hay noted “critical feedbacks” that accelerate rising sea levels. One is melting sea ice; while it does not directly contribute to rising sea levels, it still “plays a role in the overall warming of the Arctic,” with the result of ice losses in Greenland and northern Canada. When the sea ice melts, more fresh water is released from the Arctic and replaced by inflows of “brinier, warmer water from the south” that leads to the Arctic having less ice in its water. As a result, Hay explains, there are more open waters in the Arctic that absorb sunlight and trap more heat, rather than reflecting it back as sea ice does.
A second feedback factor results from last summer ‘s record-setting melting of ice in Greenland. As a result, water stored under the gigantic ice masses in Greenland (and also Antarctica) is now “being squeezed like toothpaste out of a tube,” says Hay. Right now, ice shelves are preventing the ice from emptying into the sea, but once these are gone, “nobody has any idea how fast that ice will flow into the oceans.”
Hay also points out that sea levels rose ten meters in the last interglacial period thousands and thousands of years ago, under “natural conditions” and without any human intervention. But all the carbone dioxide that we’re adding to the atmosphere is accelerating things at a rate that can’t be determined. As Hay sums it up, “Under human prodding, the system wants to go into a new climate state.”
Climate change deniers clearly need to wake up and realize that there already is no place in the world that global warming, caused by “human prodding,” hasn’t touched.
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