For at least two decades now, climate scientists have been telling us that CO2 and other human-generated greenhouse gases are warming the planet, and that if we keep burning fossil fuels the trend will continue. Recent projections suggest a global average warming of perhaps 3 to 4 degrees C, or 5.4 to 7 degrees F, by the end of this century.
But those same scientists have also been reminding us consistently that this is just an average. Thanks to all sorts of regional factors — changes in vegetation, for example, or ice cover, or prevailing winds — some areas are likely to warm more than that, while others should warm less. Далее
Picture two snowmen standing side by side beneath a spring sun. One is pristine white, the other has been coated with rusty brown dust. As the day wears on, a pool of water collects beneath the dusty snowman. He will dissolve long before the untarnished snowman loses his head.
This snowman, comprised of clean snow, will melt much slower than one speckled with dust.
The dusty snowman’s rapid demise occurs because the dark color decreases snow’s ability to reflect sunlight. The particles absorb it and conduct heat to the snowman’s body. The same process appears to have been playing out on a larger scale for 150 years in the mountains of the Upper Colorado River Basin, the birthplace of the Colorado River. Далее
Scientists have been explaining for years that the Arctic is a key region when it comes to climate change, what with thinning ice, melting permafrost and the loss of habitat crucial to the survival of major species including seals, walruses and polar bears.
Now, says a study just published in Nature Geoscience, we can add one more insult to the Arctic ecosystem that may well be at least partly climate-related: significant amounts of toxic mercury flushed into the Arctic Ocean every spring by three mighty rivers most Americans have probably never heard of: the Lena, the Ob, and the Yenisei, all of which flow north through Siberia.
“We’ve known for a long time that there’s a high concentration of mercury in Arctic biota,” said the study’s lead author, Jenny Fisher, a postdoctoral fellow with Harvard’s Atmospheric Chemistry Modeling Group in an interview. Once the neurotoxic (nerve-killing) heavy metal gets into the food supply, it doesn’t break down. Instead, it gets concentrated as bigger animals eat smaller animals on up the food chain, from plankton to fish to seals on up to polar bears, and also the indigenous Inuit, who get much of their nourishment through hunting.
Satellite view of the Lena River Delta. Credit: NASA.
Environmental experts have assumed that the mercury gets up to high latitudes through the atmosphere. It’s belched out through smokestacks of coal-burning power plants and other industrial sources and wafts up into the air, where it can circulate for a year or more before being washed out by precipitation. It all made sense in a general sort of way. Далее
Head in any direction on Michigan’s Upper Peninsula and you will reach gushing rivers, placid ponds and lakes – both Great and small.
An abundant resource, this water has nourished a small Native American community for hundreds of years. So 10 years ago, when an international mining company arrived near the shores of Lake Superior to burrow a mile under the Earth and pull metals out of ore, the Keweenaw Bay Indian Community of the Lake Superior Band of Chippewa had to stand for its rights and its water.
The Eagle Project mine is just inland from Lake Superior in the central part of Michigan’s Upper Peninsula. Credit: Michigan Department of Environmental Quality.
And now, as bulldozers raze the land and the tunnel creeps deeper, the tribe still hasn’t backed down.
“The indigenous view on water is that it is a sacred and spiritual entity,” said Jessica Koski, mining technical assistant for the Keweenaw Bay community. “Water gives us and everything on Earth life.” Далее
SEATTLE – In the long rain shadow of the Cascade Mountains, where dryland wheat farmers have eked out livings for more than a century, climate change is very much an issue of the present.
The rain gauge is always in the back of the mind for Mike Nichols, a wheat farmer cultivating 20,0000 acres across two counties in south-central Washington state.
It has to be: Nichols doesn’t irrigate, and with less than six inches of precipitation a year, his wheat crop is already on the edge of what’s considered possible for dryland farming. When drought hits or if, as expected, the West gets drier, his operation will be in trouble.
A wheat field outside of Palouse, Wash. is dusted by a January snow. Most of Washington’s wheat crop is watered only with rain falling from the sky – a future facing many farmers across the West as water supplies dwindle and the climate shifts to drier conditions. Credit: Josh Smith/flickr.
“The last eight years have been pretty good,” said Nichols. “But we are putting some [cash] aside, because down the line we know we’re going to go through another drought.” Далее