Thursday, December 3, 2009

Brown snow, browning evergreens

    What American researchers were finding up in the Rockies over the summer put a new twist on "purple mountains' majesty."

   Try, pink, or tan, or just brown where it should have been white — white as snow.

    That's what they were examining: snow with an ominous glaze of dust that had blown across time zones and oceans. It was dust that is one more signal of a planet in distress. And the thing is, the migrating dust itself is contributing to that distress.

       Climatologists call it a very troubling sign of desiccation — a long word for two short ones: "drying up." The dirt has been carried in winds from as far away as China, they say. It's not a condition confined to our own snow fields. Seasonally, increasing amounts of dust have accumulated on snow fields in the Andes, the Himalayas and China's Tian Shan range.

        Significance? The darkening of the snow from dirt and dust increases its conductivity of solar heat, causing it to melt faster. It also makes a major contribution to global heating.

      This sounds very exotic and not exactly germane to must of our earthly travails, until you hear someone who analyzes water supplies for a network of farms discuss it. Recently, a researcher for the Rio Grande Water Conservation District in Southern Colorado, which divvies up water rights from the Rio Grande, used terms like "Martian winter" and "dramatic" to describe the sped-up snow melt in the San Juan Mountains. That doesn't mean the farms won't get what they need. It does mean that a very real climatological phenomenon is happening.

       Snow isn't the only thing browning when it should be gleaming in the summer months. Massive stands of lodgepole pines are browning, not because of dust but because of a merciless pine beetle infestation sweeping across the Rockies.

        You probably don't want to hear that this has a lot to do with global warming, too. Sorry, it does.

         Longer summers, shorter periods of killing frost, give the pine beetles more time to survive, thrive and work their misery as they migrate north. As it is, the killing of the pines in some of the Rockies' most stunning forests is a slow-motion inferno that doesn't give off the billows of smoke that get people running.

         A stark projection issued by state and federal foresters in January was that every large lodgepoll pine forest in Colorado and southern Wyoming will be dead within five years. And guess what: These endangered forests are crucial carbon sinkholes that moderate greenhouse gases.

         A recent poll by the Pew Research Center finds that just as indicators of global distress continue to mount, Americans' concern about the matter is declining.

        Pew found that the number of people saying there is strong scientific evidence that the Earth has gotten warmer over the past few decades is down from 71 percent a year ago to 57 percent this year. Only 36 percent believe man-made pollution has anything to do with the warming conditions, down from 47 percent last year.

      Andrew Kohut of the research center suggested that the strains faced in the American economy are the key reasons for this.

      What? You mean evidence of global warming is contingent on Dow Jones and the unemployment rate? Apparently so.

      Even with Pew's troubling numbers, one can find encouragement in the fact that a majority of those polled — 56 percent — feel the United States should join other countries in setting standards to address global climate change.

      Maybe there is still hope down here in the fruited plain.

        John Young writes for Cox Newspapers.

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