See also:

Long-term temperatures from tree rings
 
Summer temperatures in Northern Yukon
 
Temperatures at Shingle Point
 
Precipitation at Old Crow
 
Old Crow River ice-free period

Arctic Borderlands Ecological Knowledge Co-op

What is happening?

• This set of graphs shows average temperatures for spring, summer, fall and winter at Old Crow based on measurements taken from 1951 to 2002.
• Spring and summer show a significant increase in mean temperature over time (a warming of 3.1 degrees Celsius in the spring and 1.6 degrees Celsius in the summer in the last 30 years).
• Winter temperatures at Old Crow appear to be increasing, however this pattern is not statistically significant. Average temperatures in the fall at Old Crow do not show any clear trends over time.

Why is it happening?

• Increases in global mean temperatures have been predicted as a result of increases in atmospheric greenhouse gases generated by human activities. These changes have been predicted to be greatest in the polar regions.
• Temperature changes may also result from natural climate variations, such as the decrease in temperatures that brought about the "Little Ice Age" cooling period in the 19th century for much of the northern hemisphere.
• Annual variability in mean temperatures is often large, and the detection of trends in climate generally requires long-term data sets.

Why is it important?

• Changes in global and regional climate have important implications for many aspects of the environment. In the North, temperature warming may bring about changes in sea, river and lake ice, snow conditions, permafrost, habitat for plants and animals, and other changes. For human communities, this may mean changes in agricultural productivity, sustainable hunting levels, heating fuel consumption, and patterns of land use. These effects may be both positive and negative, and are likely to vary from region to region.
• One of the greatest concerns associated with human-induced global climate change is the rate of global temperature changes - temperatures in this region are expected to increase by at least as much and faster than after the last ice age (about 10,000 years ago).

Technical Notes

• Trends in temperature were tested using data obtained between 1969 and 2000 for spring, summer and fall, and between 1969 and 1999 for winter). The trend in mean spring and summer temperatures at Old Crow is significant at p<0.05.
• The data presented in these graphs are averages of mean monthly temperature data for March-May, June-August, September-November, and December-February, provided by the Yukon Weather Centre, Environment Canada, Whitehorse, Yukon. Winter means are calculated using December values of the current year, and January and February values of the following year.
• Missing data points are due to a lack of sufficient data to calculate seasonal averages for those years.