Snowpocalypse: How Global Warming Creates Gargantuan Blizzards

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http://www.alternet.org/environment/snowpocalypse-how-global-warming-creates-gargantuan-blizzards



Severe winter storm events often prompt naysayers to mock, “Where’s that global warming?” But while the concept may seem to conflict with rising global temperatures, these storms are actually obvious evidence of man-made climate change.

Climate change, say scientists, fuels the increasing intensities of winter storms. Warmer temperatures allow the atmosphere to hold more moisture and create heavier than normal precipitation. Climatologists agree that global warming will continue to make these storms worse over time.

Weather is different from climate, scientists point out. Weather is what we experience on a day-to-day basis; climate — especially in regards to climate change — is more about long-term trends. While each describes environmental conditions, they’re on different scales of time and space. Climatologists are not in the business of watching daily and regional forecasts, they consider the larger context in which weather operates and describe long-term climate trends and how they relate to ongoing weather events.

In regard to winter weather, climatologists are looking at two different trends. First, global temperatures are 1.6 degrees Fahrenheit warmer than they were 135 years ago when measurements were first taken with accuracy. Second, what were once-in-a-lifetime snowfalls are now commonplace. There’s growing belief among climatologists that these two trends are closely related. Blizzards are generated from disturbances at the boundaries between Arctic and tropical air masses. When these fronts collide, and especially when the air mass temperatures are vastly different, it creates storms. The more divergent the air masses, the more likely the resulting storm will be large. So, as our air grows warmer and holds more moisture, the result is a lot more snow when weather fronts meet. And while you can’t attribute any one storm to the effects of climate change, a clear trend of more intense storms points in that direction.