this is probably nothing to worry about (cont'd)

Canada's forests, once huge help on greenhouse gases, now contribute to climate change

VANCOUVER — As relentlessly bad as the news about global warming seems to be, with ice at the poles melting faster than scientists had predicted and world temperatures rising higher than expected, there was at least a reservoir of hope stored here in Canada's vast forests.

The country's 1.2 million square miles of trees have been dubbed the "lungs of the planet" by ecologists because they account for more than 7 percent of Earth's total forest lands. They could always be depended upon to suck in vast quantities of carbon dioxide, naturally cleansing the world of much of the harmful heat-trapping gas.

But not anymore.

In an alarming yet little-noticed series of recent studies, scientists have concluded that Canada's precious forests, stressed from damage caused by global warming, insect infestations and persistent fires, have crossed an ominous line and are now pumping out more climate-changing carbon dioxide than they are sequestering.

Worse yet, the experts predict that Canada's forests will remain net carbon sources, as opposed to carbon storage "sinks," until at least 2022, and possibly much longer.

"We are seeing a significant distortion of the natural trend," said Werner Kurz, senior research scientist at the Canadian Forest Service and the leading expert on carbon cycles in the nation's forests. "Since 1999, and especially in the last five years, the forests have shifted from being a carbon sink to a carbon source."

Translation: Earth's lungs have come down with emphysema. Canada's forests are no longer our friends. . .