Fewer temperature reports could mean warming underestimated: scientist

Environment Canada says climate scientists who track global temperature trends may be underestimating the amount of warming in the Canadian Arctic, because they are working with data from a declining sample of weather stations across the region.

A U.S. government agency, the National Oceanic and Atmospheric Administration, compiles an important database of historic surface temperatures, based on readings from thousands of local weather stations across the planet. The raw data is obtained from the World Meteorological Organization, which receives temperatures from national governments around the world.

The number of local stations included in that database has dropped precipitously in recent years. In Canada, for example, temperature measurements for the 1970s were sampled from nearly 600 stations across the country, compared to only 35 stations today.

Only one station