This month Greenland’s ice sheet experienced dramatic change. About 97 percent of the ice sheet experienced melting over four days. The largest melt area observed by satellites over the past three decades covered just 55 percent.
Is this “proof” of global warming? Not really.
Ice core records show similar melting occurred in 1889 and indicate similar melts have happened every 150 years. Greenland’s history is filled with dramatic temperature change. The Norse Vikings arrived around 980, during a 300-year-long warm period. Then around 1100, the average temperature dropped 7 degrees Fahrenheit in about 80 years, driving the Vikings out.
A study published in the Proceedings of the National Academy of Sciences found that over the past 5,600 years the Greenland arrivals and departures of the Vikings and two other groups coincided with major, rapid temperature changes.
A changing climate is not proof that mankind is changing the climate.