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.