ENLIGHTENMENT IN THE DARK 

The fifth annual Earth Hour will be held Saturday night at 8:30, offering people around the planet a chance to collectively stop using electricity and enjoy the Earth's natural darkness. Begun in 2007, Earth Hour has evolved into a global ritual during its first four years, creating a yearly moment of reflective calm to highlight how much energy is wasted during the other 8,759 hours of the year. Earth Hour 2010 was the biggest yet, featuring a record 128 countries and territories, and organizers are expecting another vast turnout this year — including, as always, darkened landmarks like the Empire State Building, Rome's Colosseum, the Sydney Harbor Bridge and the Eiffel Tower.

Earth Hour is not without its critics, however: Some people say it's a waste of time, arguing that one hour of reduced energy consumption is pointless. As Toronto Sun columnist Brian Lilley writes, "I actually want to live in a country with clean air, clean water and clean soil to grow food in, but I fail to see how sitting in the dark for an hour once a year actually accomplishes this." This literal interpretation of Earth Hour is common among its detractors, who suggest the event hopelessly intends to fight climate change directly. But the immediate insignificance of one dimly lit hour isn't lost on Earth Hour organizers — they point out it's symbolic, serving as a touchstone to prove we can enjoy ourselves without electronic lights and gadgets. That's the idea behind their "Beyond the Hour" campaign, which aims to convert people's Earth Hour "slacktivism" (as Lilley calls it) into year-round activism.

There is one good point about Earth Hour that Lilley raises, however — it's not wise to simply trade electric light for candlelight, at least not with traditional candles. Most candles sold in North America are made from paraffin, a byproduct of crude oil. Not only would burning this fossil fuel negate your other Earth Hour efforts, but it's bad for your health, too: The fumes from paraffin candles have been linked to a variety of respiratory ailments similar to the effects of breathing other fossil-fuel hydrocarbons. Instead, why not use beeswax candles? They smell like honey and release negative ions that actually clean toxins out of the air. And, as with other Earth Hour habits, you might even want to start using them the rest of the year, too.

(Sources: Earth Hour, Wired, Independent, Toronto Sun)

'VERY GRAVE AND SERIOUS' 

The crisis at Japan's Fukushima Daiichi nuclear plant had seemed to soften a bit this week, with workers braving high heat and radioactive steam to restore the troubled reactors' power supplies. Even amid repeated evacuations and other setbacks, there was real progress taking place. Yet as many news outlets are now reporting, those setbacks appear to have grown more dire than previously believed — possibly including a breached core at one of the plant's six nuclear reactors.

"The situation today at the Fukushima Dai-ichi power plant is still very grave and serious. We must remain vigilant," Japanese Prime Minister Naoto Kan said during a somber press conference on Friday. "We are not in a position where we can be optimistic. We must treat every development with the utmost care." It's well-known that Fukushima Daiichi has been leaking low levels of radiation for a while now — already enough to force broad civilian evacuations, contaminate nearby crops and spur a water panic in several prefectures — but a core breach would mean an even worse, more widespread disaster. The Japanese government has suggested that people living directly outside the mandatory evacuation zone should begin to voluntarily evacuate, hinting at a possible expansion of the exclusion zone around the stricken power plant.

Still, Japanese officials seem to be downplaying the likelihood that a reactor is leaking,  Reuters reports, even as they revealed Friday that two hospitalized workers had been exposed to radiation levels far higher than normal. "The contaminated water had 10,000 times the amount of radiation as would be found in water circulating from a normally operating reactor," said Japanese nuclear agency official Hidehiko Nishiyama. "It is possible that there is damage to the reactor." But, he added, "It could be from venting operations and there could be some water leakage from pipes or from valves, but there is no data suggesting a crack."

(Sources: TIME, New York Times, Washington Post, Reuters)

COMING TO AMERICA 

Not only did ancient humans arrive in the Americas some 2,500 years earlier than most scientists thought, but they apparently made the trip before the famous Bering Land Bridge was accessible. According to a new study in Friday's edition of Nature, people were living in central Texas 15,500 years ago — some two millennia before the Clovis culture, long considered the earliest evidence of Native Americans, and back when glaciers still blocked off the continent's northern reaches. That means humans likely got to North America somehow besides the Bering Land Bridge, possibly traveling in boats hugging the coastline from Siberia to California — and beyond.

"This is the oldest credible archaeological site in North America," study leader Michael Waters said during a news teleconference Thursday. "This is almost like a baseball bat to the side of the head of the archaeological community to wake up and say, 'hey, there are pre-Clovis people here, that we have to stop quibbling and we need to develop a new model for peopling of the Americas.'" Waters and his colleagues found nearly 16,000 artifacts at the site in central Texas, most of which were chipping debris from making and sharpening tools. But more than 50 of the artifacts were tools themselves, modeled in a more primitive style than those at Clovis and other more recent sites. 

It has been argued for 80 years that the Clovis culture was the first group of humans to infiltrate the New World, crossing from Asia into North America via a strip of exposed land spanning the Bering Sea. But that land bridge wouldn't have been much use if it was surrounded by hard-to-cross glaciers, as it was a few thousand years before the Clovis people's arrival. This, combined with the rapid expansion of humans as far south as Chile, suggested they were coming to America by some other means. As scientists have found more and more evidence of pre-Clovis Americans in recent years, the idea of seafaring colonists from Asia has gained support. And this discovery, Waters argues, marks the death knell for the idea that Clovis people were the first Americans. "These studies will help us figure out where these people came from, how they adapted to the new environments they encountered, and understand the origins of later groups like Clovis," he says.

(Sources: New York Times, BBC News, PhysOrg)

RAISING A STINK 

Farmers and gardeners beware: Experts say a growing invasion of stink bugs in the U.S. will likely be even worse this year than in previous seasons. Long a noxious nuisance in Mid-Atlantic states, brown marmorated stink bugs are marching across the country, now occupying at least 33 states — including eight new ones they've picked up since last fall.

"I would say people now regard them as an out-of-control pest," USDA research entomologist Kim Hoelmer tells USA Today. And as an executive with the National Pest Management Association adds, the problem is only getting worse. "This season's stink bug population will be larger than in the past," says the NPMA's Jim Fredericks. The insects have been found as far west as California, as far north as Minnesota and as far south as Florida. They seem to be avoiding the Rocky Mountains and Great Plains for some reason, although there's no evidence suggesting those states are immune. And within the last few months, eight new states have joined the brown marmorated stink-bug club: Arizona, Iowa, Georgia, Michigan, Minnesota, Vermont, Washington and Wisconsin, according to the USDA.

There are more than 4,700 species of stink bugs worldwide, 250 of which live in the U.S. and Canada. Not all of them are agricultural pests; in fact, some are actually beneficial predators that feast on other pests. For now, it's just the brown marmorated stink bug that's causing a stink in the U.S. — but the problem is becoming unbearable for many farmers and gardeners, as well as other people whose homes are being overrun. "In this area, people are literally finding thousands in their homes," says a USDA entomologist in Kearneysville, W.Va. But they aren't venomous — they merely release a foul odor when threatened — so they're only a major problem for those trying to grow crops. "They feed on a wide range of important food crops," Hoelmer says. "Some growers have lost their entire crop to stink bug infestations. This adds up to many millions of dollars of losses in crop values. It's a serious economic loss to some growers."

(Source: USA Today)

THIS DAY IN HISTORY

Imminent ice-shelf collapse is confirmed, lawmaker cites biblical evidence against climate change, and more.

Russell McLendon

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Photo (New York City skyline during Earth Hour 2009): Brad Barket/Getty Images

Photo (smoke rising from Fukushima Daiichi reactor No. 3): ZUMA Press

Photo (Texas Hill Country): NASA Goddard Space Flight Center

Photo (brown marmorated stink bugs): Dendroica cerulea/Flickr

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