See also:

Details on Tree Ring Analysis
 
Temperatures at Old Crow
 
Temperatures at Shingle Point

Arctic Borderlands Ecological Knowledge Co-op

What is happening?

• This long term perspective on summer temperatures indicates a warming trend over the past 150 years. Summer temperatures have been getting warmer over the long term, according to this indirect measure, which has been obtained from looking at the widths of tree rings (see details on tree ring analysis).

Why is it happening?

• Why have summer temperatures (apparently) increased in the North over the past century and a half? Some researchers suggest this is a result of human interference with atmospheric processes by adding greenhouse gases. The long term view provided by data sets such as this point out that periods of natural warming have occurred in the past. The problem, of course, is distinguishing between the two possibilities.

Why is it important?

• Temperature is a key factor that limits many aspects of the ecosystem, especially plant growth. A long term increase in temperature may have a variety of effects on, for example, plant productivity, insect abundance, wildlife habitat and permafrost.

Technical Notes

• See details on tree ring analysis.
• Reference: Szeicz, Julian M. and Glen MacDonald 1995. Dendroclimatic reconstruction of summer temperatures in northwestern Canada since A.D. 1638 based on age-dependent modeling. Quaternary Research 44: 257-266.