Recurrent Arctic blasts in North America this year surely have some skeptics doubting the evidence of climate change. Indeed, the latest polar plunge will affect most of the U.S. this week, an unusual event for late February.
Nevertheless, the global climate is warming, polar ice is melting and the seas are rising. The incursions of Arctic air merely reflect the position of a gyrating jet stream, producing warm "ridges" and cold "troughs." As mild air flows northward from the Pacific Ocean, it displaces polar air that slides southward within the trough; of course, storm systems form along these dramatic temperature boundaries, producing the heavy snow, flooding rains and severe thunderstorms that we have witnessed this past week.
Warmer ocean waters and a warming atmosphere fuel both the dramatic jet stream gyrations and the power of the storms that they generate. Periods of intense heat and severe cold can be expected until advanced global warming grips the entire planet, a scenario we need to prevent.
