DAM NATION: There's a power vacuum developing in the United States. As fossil fuels slowly fade away, a hodgepodge of alternatives are edging into the void, and the country's longtime No. 1 renewable power source — hydroelectricity, which provides 6 percent of U.S. electricity — isn't ready to lay down for upstarts like wind and solar. But as turbines take over more and more of the power grid, some environmentalists are calling for dams to be torn down in the name of salmon. The prized fish struggle to navigate rivers in the Pacific Northwest because they're blockaded by dams, and the ones that do figure out the "fish ladders" people built for them come out "traumatized and weakened," biologists tell the NY Times. Utilities defend the dams, arguing that when winds are slow, they can balance out the power supply without falling back on carbon-heavier sources like natural gas. Still, now seems to be a watershed period for hydroelectricity. Even China, owner of the world's biggest dam, recently showed restraint by suspending two large hydropower projects to conduct environmental assessments. (Sources: New York Times, Associated Press)

 

DRILL, BABY, DRILL: After Interior Secretary Ken Salazar recently blocked 77 oil- and gas-drilling leases in the Mountain West, pressure from Republican lawmakers may force him to reinstate more than a third of them. The Interior Department issued a report Thursday criticizing the Bush administration's hasty auctioning of the leases, but also raised the possibility of reinstating or re-acutioning 30 leases located in existing areas of oil and gas development that aren't near "particularly sensitive landscapes." (Source: Los Angeles Times)

 

MOUNTAINTOP PRIORITY: The Obama administration will crack down on mountaintop-removal coal mining, officials from four agencies announced Thursday, although they stopped short of agreeing to end the practice altogether, as many critics had hoped. The move aims to reduce the worst environmental impacts of mountaintop removal by toughening the way federal permits are issued, following the lead of a federal judge in West Virginia who ruled against the Army Corps of Engineers in March for issuing such permits without conducting environmental impact studies. Mountaintop removal involves blowing up the peaks of mountains with dynamite and dumping the rubble into valleys and streams below, which can kill wildlife and pollute waterways. (Sources: NY Times, Scientific American)

 

GREEN HOUSE: The U.S. House of Representatives may conduct its own research project at the Capitol building next year, using the halls of Congress as a laboratory to test different ways of conserving energy. Under a $25 million proposal, approved this week by the House Administration Committee, the House's chief administrative officer would conduct "a series of demonstration projects" for saving electricity and even generating clean power. The bill doesn't describe specific tests that would be carried out, and some Republicans attacked it as a waste of money. (Source: Washington Post)

 

TALKING A GREEN STREAK: Despite the economic crisis, countries around the world have been showing unprecedented unity in their agreement that greenhouse gases must be cut back post haste. Unfortunately, they're also unified in their reluctance to commit to cutting back their own emissions. As the U.N. climate talks in Bonn, Germany, close today, the urgency intensifies to actually squeeze something concrete from a wealth of vague agreement. Compared with previous meetings, "the attitudes have been more constructive but the level of ambition is lower," France's climate ambassador tells the AFP. Some of the trickiest disputes are between developed and developing countries — namely the United States and China — and must be ironed out before a replacement to the Kyoto Protocol can be drafted at December's make-or-break Copenhagen summit. (Source: Agence France-Presse)

 

EVERYTHING BUT THE CARBON SINK: One way developed countries can boast smaller carbon footprints without actually reducing their carbon emissions is to start including the effects of major carbon sinks, some negotiators proposed at the Bonn talks. Large forests and bogs absorb carbon dioxide from the air, mitigating the effects of burning fossil fuels — U.S. forests alone soak up about 10 percent of the country's entire output of greenhouse gases. This technique could help cajole these countries' into accepting more stringent emissions cuts, although there is a catch: Forests also release huge amounts of carbon when they burn, and Australia is demanding that natural disasters like its recent brush fires not count as part of its emissions. (Source: Bloomberg News)

 

OUR DEERLY DEPARTED: Populations of reindeer and caribou around the world have dropped nearly 60 percent in the last three decades, according to a new study, which blames climate change and habitat encroachment for the decline. "Their future is dubious if climate change and habitat disturbance continue at their current pace," one of the study's authors tells LiveScience. "We do not know how quickly they can adapt to this changing world." The two animals are actually one — caribou live in North America and reindeer are European, but they're technically the same species. In addition to the dangers of losing a species, die-offs of reindeer and caribou threaten people in the regions who depend on them for their livelihoods. (Source: LiveScience) 

 

GET OFF OF MY CLOUD: Weather watchers and officials are mulling whether to create a new category of cloud — which hasn't been done since 1951 — based on photographs taken by an Iowa woman in 2006 (right). The Cedar Rapids paralegal spotted clouds that "looked like Armageddon," eerily undulating, rolling and shimmering as they hung low over the city, and she shot several photos before they dissipated 15 minutes later. Some skeptical climate scientists say the clouds already fit into the cumulus category, but others are pushing for a cumulus sub-classification, "altocumulus undulatus asperatus." (Source: AP)

 

And to catch up on anything you might've missed during the last week, check out MNN's week in review.

 

— Russell McLendon

 

(Top photo: Salmon pass through a fish ladder at Bonneville Dam in North Bonneville, Wash. Source: Don Ryan/AP)

 

(Bottom photo: Clouds photographed in Cedar Rapids, Iowa, on June 20, 2006. Source: Jane Wiggins/AP)