Climate data show that winter temperatures in the northernmost regions of the world have warmed alarmingly in a very short period. Parts of Alaska and northern Eurasia, for example, have warmed by nearly 11 degrees Fahrenheit in the winter months over the past 30 years. Climate evidence from the past four centuries gleaned from ice cores, lake cores, and tree rings indicates a gentler warming trend that extends back 400 years.
This image shows the winter temperature trend in the Arctic from 1966 to 1995. The scale is in degrees Celsius per decade. Over the 30-year period shown, average winter temperatures in central Siberia warmed by as much as 6°C.
For more information, visit the State of the Cryosphere.
Image courtesy National Snow and Ice Data Center.
