The graph above shows the average ("mean") summer temperature in two Alaskan communities-- Fairbanks and Nome-- over a span of nearly 100 years. The year-to-year temperatures vary (the zig-zag ups and downs in yellow and in blue), but the white lines are trend lines. This graph demonstrates an increase in the mean summer temperatures for both communities over these last 70 to 90 years. A note: the climate changes over time (over hundreds, thousands, millions of years), but the IPCC (Intergovernmental Panel on Climate Change) says that the global warming that is occuring now is influenced by human activities. Compared to previous climate changes, scientists are concerned about the speed of this warming. Click here to get more information about climate change and links to cool climate sites.

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