A new study published in the journal Nature suggests that Canada's boreal forest may in fact be releasing more greenhouse gases than it absorbs. 

     "The boreal forest, at least in the north-central part of Manitoba, has gone from a weak carbon sink to a weak carbon source," said Dr. Tom Gower of the U of Wisconsin.  His team studied a million square kilometers of forest, and concluded "it is now contributing to atmospheric [carbon dioxide] concentration."

     The forest once absorbed, on average, slightly more carbon than it emitted - about 5 or 10 grams per square meter of forest per year.  Now the flow has reversed, with the forest actually emitting about 2 grams per square meter per year.  (CP)