<a href=http://mrbdc.mnsu.edu/mnbasin/fact_sheets/glaciers.html">Minnesota glaciation during the Wisconsin Glaciation era.

"The most recent advancement of glacial ice in Minnesota spanned from around 12,000 to 10,500 years ago. By this time, the ice had melted back out of Iowa and up into the lowland area of Minnesota. When these lobes melted back into the Red River Valley and the Lake Superior Basin, Glacial Lake Agassiz was formed. By 9,000 years ago, the ice sheets had melted completely from the state but the glacial lakes remained."

During the Wisconsin Glaciation period glaciers covered 97 percent of Canada and parts of northern United States. The glaciers receded into Canada by 9000 years ago but even today much of the arctic still has permafrost. In southern Canada the ground thaws during the summer and freezes during the winter. Further north, the summer thaw gets shorter, until somewhere in the NWT it remains frozen year-round. With the warming trend continuing over the last 10,000 years the summer thaw is getting a bit longer in some places.

Wheat supplies 20 percent of food calories for the world's people and contains a vitally important 15 percent protein by weight. Global wheat production is about 600 million tonnes, of which 24 million tonnes (4 percent) is grown in Canada, but which exports 2/3rds of its crop, representing 15 percent of worldwide export market share. If there were another glaciation event, all that would disappear.

Some countries have insufficient domestic supply of wheat, such as Egypt, Japan, China, and Brazil. Upwards of 110 million tonnes (18 percent) of global wheat crop are imported into parts of the world with insufficient supply.