The latest version of the government’s official map of Canada has attracted criticism for the amount of sea ice coverage it shows in the Arctic.
The previous version of the map, from 2006, showed only the permanent polar ice cap. But the version published on 15 April uses a different method to calculate ice cover, showing the median level of ice over 30 years for the month of September, when ice coverage hits its seasonal low.
That method is in line with international standards, but the result is that more Arctic waters are shown as ice-covered, despite warnings over shrinking ice coverage as a result of increases in global temperatures. Denis Dubé, a senior forecaster with the Canadian Ice Service, defended the change. "We decided to provide a median over 30 years so we could compare actual conditions, as opposed to just what is represented by the permanent polar cap coverage," he told CBC News.