An enhanced greenhouse effect caused by human activities will upset the radiation balance of the earth system creating a variety of changes in the geography of planet Earth, the most notable being air temperature. Temperature trends over the past 100-plus years clearly indicate rising temperatures on all continents and over the oceans.
The arctic regions appear to be impacted the most. Observations of mean annual surface air temperature over the past 50 years has increased 3.6oF to 5.4°F in Alaska and Siberia and decreased by 1.8°F over southern Greenland. Mean annual surface air temperature over the Arctic region (north of 60° latitude) is projected to increase 3.6°F by 2050 and 8°F by 2100.
Discovery News took a look at the effects of global warming on Alaska that are presently occurring.