WASHINGTON – Changing wind patterns linked to global warming are altering the food chain in Antarctica and may lead to further increases in greenhouse gases in the atmosphere. The most basic food, plankton, is declining in the northern portions of the Antarctic peninsula reaching toward South America, researchers report in Friday's edition of the journal Science. At the same time, populations of Adelie penguins, who require a colder climate, have dropped sharply in that region, while warmer-weather chin-strap penguins have increased. "We're showing for the first time that there is an ongoing change on phytoplankton concentration and composition along the...