Arctic takes the heat
BBC News
New research reveals that Arctic temperatures are now higher than at any time in the last 2,000 years. Evidence taken from ice cores, tree rings and lake sediments reveals a long, slow cooling trend followed in the last century by an abrupt warming, particularly over the past few decades.
So what?Changes in Earth's orbit have decreased the amount of solar energy reaching the Arctic region in summertime. So the sudden rise in temperature this century is due to greenhouse gas emissions, which have increased melting of the Arctic ice cap.