The oceans reach new warmth records and acidify. The Arctic sea ice melts. Scientific news can be grim. Instead, let's walk through a cool, green, and leafy forest, as did Henry David Thoreau:
"I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived."
We can visit the trees of Minnesota with Saint Bernard:
You will find something more in woods than in books. Trees and stones will teach you that which you can never learn from masters.
In northeastern Minnesota, paper birch trees on south-facing slopes are dying as the prairie moves north. Two University of Minnesota professors studying the 1,700 mile long border between prairie and forest conclude that the border will shift up to 300 miles north: "As temperatures increase, droughts, violent storms and fires will become more frequent. Insects, some new to the region, will become more numerous and damaging. Invasive earthworms will continue their march north, consuming the forest floor's protective duff and warming and drying the soil. White-tailed deer will become more numerous, eating away at the forest's ability to regenerate as it otherwise would. It's not just that it will be a few degrees warmer, but all these other threats are going to be more prevalent than they were in the past."
Many changes are occurring faster than even the forestry professors expected: "No explanation other than drought-related climate change appears to make sense." Red maple trees, for example, are becoming more abundant and sprouting in burned-over areas near the Minnesota-Ontario border.
Or we can visit the trees of Western United States and Canada with Robert Louis Stevenson:
It is not so much for its beauty that the forest makes a claim upon men's hearts, as for that subtle something, that quality of air that emanates from old trees, that so wonderfully changes and renews a weary spirit.
Mountain pine beetles have long infested the pines of the Western United States and Canada in limited numbers. The beetles bore into a tree; over time (usually within 2 weeks of attack), the tree is overwhelmed as layers of bark are damaged enough to cut off the flow of water and nutrients. In the end, the tree starves to death. From the air, entire groves of trees after an outbreak will appear reddish. The lodgepole pine -- one of the most common trees of higher elevations -- has evolved defenses, including a thick bark, that normally would repel the beetle. Normally, the trees' best defense is a few days of a harsh winter: one cold snap of night temperatures below -40 degrees will kill them. And normally, a controlled burn will eradicate an outbreak. But these are not normal times.
A pine-beetle infested forest of dead trees near the Grand Tetons (credit Kurt Repanshek):
In British Columbia, the current outbreak of mountain pine beetles is "an order of magnitude larger in area and severity than all previous recorded outbreaks." The beetle has converted an affected forest from a small carbon sink -- a place that captures carbon -- to a carbon source -- decaying trees emit carbon into the atmosphere. A dead and dessicated tree is more likely to burn than a living tree. Economists studying wildfires (22 pg pdf) in Montana concluded: "We find that a one degree increase in average spring and summer temperature is associated with a 305 percent increase in area burned, and a 107 percent increase in home protection costs." Of course, the cost of protecting a home from wildfire pales in comparison to the long term damage that occurs when a carbon sink is turned into a carbon source.
And we can visit trees of the Siberian permafrost permamelt with Anton Chekhov:
Man has been endowed with reason, with the power to create, so that he can add to what he's been given. But up to now he hasn't been a creator, only a destroyer. Forests keep disappearing, rivers dry up, wild life's become extinct, and the climate's ruined and the land grows poorer and uglier every day.
The taiga, or boreal forests, are comprised primarily of evergreen spruce, fir, and pine along with some tough deciduous trees. They're found in Siberia, Canada, northern Scotland, northern Japan, and the Scandinavian countries. In America, they not only include most of Alaska but also far northern parts of Minnesota, Michigan, New Hampshire, upstate New York, and Maine. They're home to caribou, moose, grizzly and black bears, wolverines, wolves, lynxes, and smaller animals.
Siberia has already been hit hard by global warming, with temperatures already up two degrees Celsius and eight of the past ten summers being extreme wildfire seasons. Smoke drifts as far away as the United States. American and Russian researchers working together find that "a warmer, drier climate appears to be stifling regrowth of burned-out areas on the Siberian forest's southern edge, turning them to grasslands," while girding for a surge in the highly destructive Siberian moth, a caterpillar that devours forests of pine, spruce, fir and larch.
North of the taiga is was the permafrost, or tundra. As Joe Romm explains: "The tundra or permafrost is soil that stays below freezing (0°C or 32°F) for at least two years. Normally, plants capture carbon dioxide from the atmosphere during photosynthesis and slowly release that carbon back into the atmosphere after they die. But the Arctic acts like a freezer, and the decomposition rate is very low. The tundra is a carbon locker. We open it at our own risk."
Oops, we already did open that locker! A frozen peat bog the size of France and Germany has been melting since 2005. As it melts, it releases methane and carbon into the atmosphere. A Russian botanist describes it as "an ecological landslide that is probably irreversible and undoubtedly connected to climatic warming." It's termed a "positive feedback" that amplifies existing warming, although I don't see anything positive about it.
Or we can skip the tour of the forests and instead comfort in the immortal words of one of America's greatest Presidents, Ronald Wilson Reagan:
A tree is a tree - how many more do you need to look at?