Posted on 04 February 2011.
An extensive drought in the Amazon rain forest last year spurred massive carbon dioxide emissions, British and Brazilian scientists said Thursday. They fear the devastating event may become a common occurrence, turning the world’s largest rain forest from an absorber of heat-trapping gases into a source of the harmful emissions.
Simon Lewis, an ecologist at the University of Leeds, and his team of researchers said in a study published Thursday that 2010′s crippling dry spell was worse than a “once-in-a-century” 2005 drought and may have caused more emissions than the United States does in a year.
Forests abundant in vegetation help diminish carbon dioxide in the atmosphere by soaking it up as they grow, but they release the heat-trapping gas when they die and biodegrade.
The 2010 drought was severe enough to leave major Amazonian rivers dry, stranding thousands who depend on boat transport. It followed the region’s dry spell in 2005, a drought so severe that scientists had dubbed it a “once-in-a-century” event at the time.
But last year’s drought was even more intense than the one five years before, scientists discovered. It caused rainfall shortages that affected a 1.16 million square-mile expanse of the Amazon, compared with the 734,000 square miles exposed to drought in 2005.
The 2010 dry spell also caused higher tree mortality and had three major epicenters, as opposed to the 2005 drought, which was mainly concentrated in one area in the southwestern Amazon.
The Amazon typically soaks up around 1.5 billion metric tons of carbon per year. According to the study, the forest will release 5 billion metric tons of greenhouse gases in 2010 and 2011 for a total impact of about 8 billion metric tons. That’s below the United States’ carbon dioxide emissions in 2009, which were approximately 5.4 billion metric tons.
“If events like this happen more often, the Amazon rain forest would reach a point where it shifts from being a valuable carbon sink slowing climate change to a major source of greenhouse gases that could speed it up,” Lewis said.
The study was published in Thursday’s edition of the journal Science.
Posted in Drought & Shortages, Global Warming, Natural Disasters
Posted on 20 March 2010.
BANGKOK, March 20 (UPI) — Senior Thai officials plan to meet with Chinese officials in the first high-level bilateral talks on the drought along the Mekong River, authorities say.
The Bangkok Post reported Thai Prime Minister Abhisit Vejjajiva plans to attend the proposed talks, which would be held on the sidelines of the Mekong River Commission meeting in Hua Hin, Thailand, from April 2-5, Kasemsun Chinnavaso, chief of the Thai Water Resources Department, said.
But China has yet to say whether its prime minister or a deputy will attend the meeting, he said. China, which is not a member of the MRC, is set to join the summit as a dialogue partner.
The water department chief said Bangkok would ask China about the operation of Chinese dams on the Mekong.
Downstream countries have been affected by changes in the river’s flow since China started operating three dams two years ago, Kasemsun said.
Local residents and activists say China’s dams are the major cause of the severe water shortages along the river, the Post reported.
Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.
Posted in Drought, Drought & Shortages
Posted on 22 December 2009.
ST. HELENA, Calif., Dec. 21 (UPI) — Slowing the rate of delivery would reduce the amount of water lost in vineyards in California’s Napa Valley, a Stanford researcher said.
Using water efficiently is a priority in the Napa Valley, where summers are hot and dry and grapevines must be irrigated to thrive.
Deep cracks caused by the natural shrinking and swelling of soil means that at least 10 percent of irrigation water bypasses vine roots and is wasted, Stanford researcher Eve Hinckley said.
Growers could reduce water loss by lowering irrigation drip lines to the ground or burying them, she said.
Growers also could slow the rate from drip emitters and irrigate earlier in the day for a longer period of time to allow more water to soak into the roots, rather letting the water bypass them altogether, the university said in a release Friday.
Copyright 2009 by United Press International
Posted in Drought, Drought & Shortages, Farming & Ranching, Land & Soil, Water Efficiency