CNN: global warming didn't cause drought

[novasteve]

Breaking story CNN.com - Breaking News, U.S., World, Weather, Entertainment & Video News

 

[waltky]

Did pollution cause African drought?...

Study: Pollution Led to African Drought
June 07, 2013 > Decades of drought in central Africa may have had a surprising cause, according to new research that challenges the notion that the severe dry weather was triggered mainly by bad agricultural practices and overgrazing.

The research, done at the University of Washington, shows that the drought was at least partially caused by pollution in the Northern Hemisphere. The researchers said that sulfate-laden aerosols coming from coal-burning factories from the 1960s through the 1980s actually slowed warming in the Northern Hemisphere compared to the Southern Hemisphere. This shifted tropical rain bands south, away from the Sahel region, and led ultimately to the near drying up of Lake Chad, which is used to water crops in surrounding areas. “We think people should know that these particles not only pollute air locally, but they also have these remote climate effects,” said the study’s lead author, Yen-Ting Hwang, a University of Washington doctoral student in atmospheric sciences.

Hwang’s co-author, Dargan Frierson, an associate professor of atmospheric sciences at the University of Washington, said “to some extent, science messed this one up the first time around.” “People thought that a large part of that drought was due to bad farming practices and desertification,” he said. “But over the last 20 years or so we’ve realized that that was quite wrong, and that large-scale ocean and atmosphere patterns are significantly more powerful in terms of shaping where the rains fall.”

Through the 1980s, rainfall in the African Sahel declined more than anywhere else in the world, causing increased aridity, as evidenced by this dust storm in Senegal.

Researchers also studied rainfall in other places on the northern edge of the tropical rain band such as northern India and South America. These areas also experienced less rainfall during the 1970s and 1980s. Meanwhile, areas on the southern edge of the tropical rain band, such as northeast Brazil and the African Great Lakes, saw an increase in rainfall. The researchers also looked at 26 climate models used by the Intergovernmental Panel on Climate Change, and found that nearly all the models showed some southward shift in rainfall and that slowed warming in the Northern Hemisphere was the “primary cause.” “One of our research strategies is to zoom out,” said Hwang. “Instead of studying rainfall at a particular place, we try to look for the larger-scale patterns.”

There was a silver lining found in the research. The study showed that steps taken in the United States and Europe in the 1960s and 1970s to reduce emissions and improve air quality began to improve the situation in the Sahel. While the area still suffers short-term droughts, “the long-term drought began to recover in the 1980s” as the rains began to move north again, according to the research. “We were able to do something that was good for us, and it also benefited people elsewhere,” Frierson said. It’s a trend that Hwang says is likely to continue. As the atmosphere gathers higher levels of greenhouse gases, however, Hwang said the Northern Hemisphere will warm more rapidly than the Southern Hemisphere because there is more land. “It’s not yet crystal clear what will happen,” she said. “There will be some shift in the tropical rains, and most models predict a northern shift.”

Study: Pollution Led to African Drought

 

[waltky]

Granny says it might be one o' dem 7-years drought like inna Bible...

Drought has western US states fearing the worst
Tue, Feb 04, 2014 - The punishing drought that has swept California is now threatening the state’s drinking water supply.

With no sign of rain, 17 rural communities providing water to 40,000 people are in danger of running out of water within 60 to 120 days. California’s State Water Project, the main municipal water distribution system, announced on Friday last week that it did not have enough water to supplement the dwindling supplies of local agencies that provide water to an additional 25 million people. It is first time the project has turned off its spigot in its 54-year history.

California officials said they were moving to put emergency plans in place. In the worst scenario, they said drinking water would have to be brought by truck into parched communities and additional wells would have to be drilled to draw on groundwater. The deteriorating situation would likely mean imposing mandatory water-conservation measures on homeowners and businesses, who have already been asked to voluntarily reduce their water use by 20 percent. “Every day this drought goes on we are going to have to tighten the screws on what people are doing” said California Governor Jerry Brown, who was governor during the last major drought here, in 1976 and 1977.

This latest development has underscored the urgency of a drought that has already produced parched fields, starving livestock and pockets of smog. “We are on track for having the worst drought in 500 years,” said B. Lynn Ingram, a professor of earth and planetary sciences at the University of California, Berkeley. Already the drought, technically in its third year, is forcing big shifts in behavior. Farmers in Nevada said they had given up on planting, while ranchers in Northern California and New Mexico said they were being forced to sell cattle as fields that should be 1.2m high in grass are a blanket of brown and stunted stalks.

Fishing and camping in much of California has been outlawed to protect endangered salmon and to guard against fires. Many people said they had begun to cut back drastically on taking showers, washing their car and watering their lawns. Rain and snow showers brought relief in parts of the state at week’s end — people emerging from a movie theater in West Hollywood on Thursday evening broke into applause upon seeing rain splattering the sidewalk — but they were nowhere near enough to make up for record-long dry stretches, officials said. “I have experienced a really long career in this area, and my ‘worry meter’ has never been this high,” said Tim Quinn, executive director of the Association of California Water Agencies, a statewide coalition. “We are talking historical drought conditions, no supplies of water in many parts of the state. My industry’s job is to try to make sure that these kind of things never happen. And they are happening,” he said.

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