AFTERSHOCK 

Rescuers are poring through the rubble in Christchurch, New Zealand, today, using everything from heavy construction equipment to their bare hands in a race to find survivors from Tuesday's deadly earthquake. The confirmed death toll had risen to 75 by Tuesday night, and with some 300 people still reported missing throughout the city, officials say it will almost certainly continue to climb.

There are still some bright spots, though — about 120 people were rescued overnight Tuesday, according to Christchurch Mayor Bob Parker, including one woman who was dramatically extracted from the fallen Pyne Gould Corp. building. Cheers erupted from a crowd of onlookers as Ann Bodkin was pulled from the building's ruins, just as rays of sunlight poked through the clouds over Christchurch. "They got Ann out of the building, and God turned on the lights," Parker said. Yet not all the rescues were so glorious, with one firefighter forced to saw off a man's leg to free him from the same building. "It's a necessity of the game," explains a rescuer who handed the firefighter a hacksaw. "How are you gonna get out?" And as the AP reports, anyone who does get out is among the lucky few: Many collapsed buildings seem to have killed everyone inside, such as the Canterbury Television building, a seven-story structure so badly damaged that police say it isn't "survivable."

While the shaken city of 350,000 recovers from this disaster — its second major earthquake in less than six months — seismologists say Tuesday's quake highlights the danger of shallow tremors, both in New Zealand and elsewhere. "When you combine the shallow depth, proximity to a major city and soil characteristics, it was capable of immense damage," says Oregon State University geologist Robert Yeats. "The same characteristics that caused such destruction and so many deaths in Christchurch are similar to those facing Portland, Seattle, parts of the Bay Area and many other [U.S.] West Coast cities and towns," he adds. "And it's worth keeping in mind that New Zealand has some of the most progressive building codes in the world. They are better prepared for an earthquake like this than many U.S. cities would be."

(Sources: Associated Press, Washington Post, CNN, e! Science News)

FAT AND FURRY 

American pets have a weight problem, with one-fifth of all U.S. dogs and cats meeting the requirements to be called "obese." That's according to a new survey conducted by the Association for Pet Obesity Prevention and Banfield Pet Hospital, the country's largest general veterinary practice. The survey found that 20 percent of the roughly 171 million pet dogs and cats in the U.S. are obese — meaning they're at least 30 percent above normal weight — and that pet owners spent $25 million on vet bills for obesity-related conditions in 2010 alone. 

"Obesity in pets is almost the equivalent of smoking in human medicine," University of Georgia veterinary researcher Steven Budsberg tells the Wall Street Journal. "There's the high cost to people, and it's self-induced. I never met a German shepherd who could open the refrigerator or food bag and pour himself another bowl." Part of the problem is that pet obesity has long been overlooked as a real medical problem, or was considered "taboo" by the veterinary community, the founder of APOP tells the Journal. "There are sensitivities to an owner's own weight condition," he says, "and to making them feel guilty for overfeeding their pet." Many owners are also unsure how much they should be feeding their pets, or how to know when an animal is too fat. To help, many vets are introducing new diagnostic and prevention tools, such as software for doctors to track a pet's "Body Condition Score," a blood test that can quickly determine its body-fat percentage, a Weight Watchers-style diet program and even treadmills.

Some pet-food makers are also offering leaner grub, like Purina's "Project: Pet Slim Down," or Science Diet's new pre-measured meal packets. But companies aren't required to list calorie contents unless the product advertises itself as "low calorie," and while the FDA is considering changing that, for now owners must largely figure out for themselves how much is too much. There is one easy way to mitigate overfeeding, though: Exercise. Larger dog breeds need 30 to 60 minutes of daily activity, while smaller breeds need 15 to 30 minutes; cats, on the other hand, prefer brief 5- to 15-minute bursts. As the CEO of one dog-exercise camp tells the Journal, encouraging exercise can help owners as well as their pets. "It goes to the dynamic of people looking like their pets," says Heidi Ganahl of Camp Bow Wow. "If the owner is focused on health, then the pets will be, too."

(Sources: Wall Street Journal, TIME)

RAGTIME 

If you think climate change is nothing to sneeze at, a new study by the U.S. Department of Agriculture begs to differ. Global warming has stretched out the allergy season in northern U.S. states by 16 days, and by nearly a month in parts of Canada, according to the USDA. "It isn't just theoretical," USDA plant expert Lewis Ziska tells the Minneapolis Star-Tribune. "We are seeing these changes reflected in terms of the actual pollen season length." One of the pollen-producing plants that benefits the most from rising temperatures, the study suggests, is ragweed (pictured above).

The problem is that there are fewer frost-free days as the climate heats up, giving ragweed plants more time to pump out pollen. The allergy season is now more than two weeks longer in states like Minnesota and North Dakota than it was in 1995, the USDA found, and up to 27 days longer in Canada. And it's not just season length — preliminary studies show that higher levels of carbon dioxide in the atmosphere also increase the amount of pollen that ragweed produces each year. "Climate change increases pollen production. There's more pollen on any given day," says David Frenz, a pollen expert in Minneapolis. "And the duration of the season is longer. That's two reasons that people are more symptomatic."

The USDA researchers have also shown that cities like New York have higher ragweed productivity than rural areas, but there is at least a silver lining to their research: While global warming is bringing longer ragweed seasons to northern regions, it may also be shortening the hay fever season in states farther south, such as Arkansas and Texas.

(Sources: Minneapolis Star-Tribune, New York Daily News)

OMG, GMO 

Whether you like them or not, genetically modified organisms — better-known as GMOs — seem to be slowly taking over the world. According to a new report by a pro-GMO nonprofit group, the amount of land dedicated to genetically modified crops grew 10 percent in 2010, up from 7 percent growth the year before, as farmers in major grain- and soy-exporting countries like Argentina and Brazil adopt GMO seeds in droves. GMO or biotech crops now cover 10 percent of the world's farmland, up from zero percent less than two decades ago.

Advocates of GMOs argue they're a necessity to feed the planet's ballooning human population, since such crops are genetically engineered to be pest-resistant or to better endure the chemical pesticides that farmers spray on their fields. This often helps them produce larger yields, especially when combined with chemical fertilizers. The most common gene modification is for herbicide tolerance, a trait carried by 61 percent of all biotech crops to help them survive the weed killer glyphosate, branded commercially as Roundup. Major GMO crops include soy, corn, cotton and canola, and are planted in 29 countries worldwide, led by the U.S., which has 165 million acres of genetically modified food. Brazil is No. 2 with 63 million acres, followed by Argentina's 56 million. 

Not everyone is so enamored with GMOs, though. Many critics, such as the Union of Concerned Scientists, warn that such widespread adoption of a relatively new technology could pose unknown dangers to the hordes of people eating GMOs — many of whom don't even know they're eating genetically altered food. Critics also point out that GMOs are helping weaken the very herbicides they're designed to support, since the Roundup-resistant weeds have begun to proliferate in recent years. 

(Source: USA Today)

THIS DAY IN HISTORY

Plutonium is discovered, an atomic-bomb plant is built, and more.

Russell McLendon

Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.

Photo (earthquake damage in Christchurch): ZUMA Press

Photo (obese dog): ZUMA Press

Photo (ragweed): National Institute of Environmental Health Sciences

Photo (anti-GMO protesters in Belgium): ZUMA Press

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.