Earthweek : A Diary of the Planet (Feb. 15, 2013)

Survival Plan
Polar bears may need to be fed in the wild, housed or relocated by humans within the next few decades to help them survive a warming climate, according to a new report.  Climate change has resultedin accelerated loss of Arctic seaice, which polar bears rely on to hunt for food.  If the Arctic becomes ice-free during summer within the next few decades as predicted, many bears will starve without human intervention.  Some members of the 19 polar bear populations in Canada, Alaska, Greenland, Norway and Russia may even have to be placed in temporary holding compounds until enough ice forms for them to go back into the wild.  Currently, none of those countries has plans to help the animals survive.  But 12 research scientists from Arctic countries have crafted a crisis management plan designed to save as many as possible of the world's estimated 20,000 remaining polar bears.  Part of the plan would be to have zoo's take in as many bears as they can hold.  If no other action can be taken, experts say the only humane choice would be to euthanize bears to avert agonizing deaths by starvation.
Smog Stunts Newborns
A new U.K. based study of more than 3 million births in nine countries has shown that exposure to air pollution is linked to low birth weights.  Scientists looked at the average level of air pollution to which expecting mothers were exposed, specifically exhaust and power plant emissions.  They found that pregnant women living in areas with high pollution were more likely to have babies with low birth weight.  Being undersized at birth has been linked with infant mortality as well as a host of diseases and chronic health problems.
Ozone Healing
The hole in the stratospheric ozone over Antiarctica has shrunk to the smallest size in a decade, according to satellite observations.  The swirling area of depleted ozone typically reaches its maximum geographical coverage around the South Pole in late September and its maximum depth in early October.  The ozone depletion allows harmful ultraviolet radiation to reach Earth's surface rather than being filtered out by the gas.  Until a global ban on the production of ozone-depleting chlorofluorocarbons was adopted in 1987, there had been a steady decline of about 4 percent per decade in the total volume of Earth's stratospheric ozone.  A slow reversal in the trend has been observed over the past decade even though there was a record ozone loss in 2011 due to unusual weather patterns.  Scientists say the ozone hole will vary in size from year to year as it continues to close up in the decades ahead.
Nuclear Trigger
A South Korean geologist warns that North Korea's latest nuclear test on Feb. 12 threatens to jolt a nearby volcano into a new eruptive phase.  Yoon Sung-ho of Pusan National University told the Yonhap News Agency that the force of the blast could help reactivate the dormant Mount Baekdu, which lies just north of the blast site along the North Korea-China border.  He points to satellite observations days after North Korea's 2006 nuclear test that showed an increase in surface temperature, probably due to an expanding magma pool beneath Baekdu.  North Korean volcanologists say they observed abnormal activity at a lake atop Mount Baekdu after Japan's 9.0 magnitude earthquake in March 2011.
Tropical Cyclones
Tropical Storm Haley brought squalls to southernmost islands of French Polynesia.  Such stormsrarely form so far south in the Pacific.
* Cyclone Gino passed over the open waters of the central Indian Ocean.  It was a threat only to shipping in the remote region.
Earthquakes
At least 15 people were injured when a 6.9 magnitude temblor wrecked homes in southwestern parts of Colombia.  The shaking also rocked tall buildings in the capital, Bogota, as well as in Ecuador's capital of Quito.
*  Earth movements were also felt in Central Chile, Trinidad and Tobago, New Zealand's South Island, northern India, western China's Qinghai province and western Nevada.
Beaver Helpers
Canada geese get a wing up in raising their young thanks to beavers that help their nesting ponds thaw almost 11 days earlier than lakes without the toothy creatures.  Researchers from the University of Alberta report that beaver activities like building lodges and foraging for food help thaw the waters of their ponds.  This creates a more welcoming habitat for geese migrating northward in spring to nest.  The open waters slso help out a number of other creatures, such as moose, deer, coyotes and birds, according to the research.  The findings, published in the journal Mammalian Biology, show that beavers are key to the success of other wildlife and help protect sub-Arctic wetlands against drought.