Stories tagged global climate change

Is it the changing climate, nasty bugs, a virus or some other mysterious cause? That's what researchers are asking right now in northern Minnesota as they investigate the dramatic decline in moose numbers. The Star-Tribune has excellent coverage of the situation and what's being done to figure out this problem.

Feb
15
2008

Drawing down: The white banks show the one-time high water mark of Lake Meade in Arizona. One group of researchers say there's a 50 percent chance the lake could dry up by the year 2021
Drawing down: The white banks show the one-time high water mark of Lake Meade in Arizona. One group of researchers say there's a 50 percent chance the lake could dry up by the year 2021Courtesy amysh
Have you ever been to Hoover Dam? It’s a popular day trip destination for those looking for a break from the gambling in Las Vegas.

One of the impressive sights is the huge body of water stopped up behind the dam: Lake Meade. The water stretches and snakes for miles and miles upstream on the Colorado River, which cuts its way through the Grand Canyon. That reservoir of water is also the main drinking supply for much of the southwest U.S.

But analysts from San Diego's Scripps Institution of Oceanography that there’s a 50 percent chance that water will dry up by 2021. In a shorter time span, they say that there’s a 10 percent chance water in the lake will not be usable for drinking by 2013, just five years away.

The dire predictions are based on global climate change factors along with a growing demand for water in southern Nevada and southern California.

Due to current drought conditions, Lake Meade and its sister reservoir, Lake Powell upstream from the Grand Canyon, are only currently half full. Combined, they provide water to 27 million people spread over seven states.

But an official from the Central Arizona Project said that the predictions are alarmist and absurd and that the reservoirs are in no danger of drying up.

And I remember just a couple weeks ago we posted a story here on the Buzz that Rocky Mountain areas have seen wondrous amounts of snowfall this winter. A lot of that snow runoff finds its way into the Colorado River.

Do you have any deep thoughts to share on the southwest water situation? Post them here and let other Science Buzz readers know how you feel.

Jan
30
2008

Fighting for survival?: Delays by the Department of Interior on putting polar bears on the endangered list have made some congressional leaders upset. What do you think about this?
Fighting for survival?: Delays by the Department of Interior on putting polar bears on the endangered list have made some congressional leaders upset. What do you think about this?Courtesy wikipedia
Congressional environmentalists were getting cranky last week as deadlines are coming and going on giving polar bears endangered species protection. At the same time, deadlines are coming to open up some prime polar bear locations to oil exploration.

The Chukchi Sea, home to about a fifth of the world’s polar bears, could be opened to oil and natural gas expeditions next week through the action of one Interior Department division.

Congressional environmentalists, who want to see polar bears be added to the endangered list, claim they were promised that action would happen earlier this month. Now, they claim, the delay is being made to keep the Chukchi open to energy discoveries.

Proponents of global climate change say that melting ice caps in the Arctic are threatening the polar bear population. One study completed this fall predicts that up to two thirds of the polar bear population could be gone by the middle of this century if current warming trends continue.

Interior officials testifying at Congress yesterday said that the delay on adding polar bears to the endangered list is due to a desire to assure that Congress and the public will understand the decision when it is made public.

What do you think of all of this? Share your thoughts here with other Science Buzz readers.

Sep
22
2007

Blue cloud skies: This noctilucent cloud was photographed last summer over the United Kingdom. The bluish-glowing clouds are showing up the sky much more often, possibly due to global warming. (Photo by Alex Lloyd-Ribeiro)
Blue cloud skies: This noctilucent cloud was photographed last summer over the United Kingdom. The bluish-glowing clouds are showing up the sky much more often, possibly due to global warming. (Photo by Alex Lloyd-Ribeiro)
The reports are coming in more frequently of weird sights in the evening sky. And we’re not talking about people seeing UFOs.

What they’re seeing are noctilucent clouds. The clouds look like your regular cirrus cloud but as the sun has set, they shimmer with a blue, electric glow that can be seen from people on the ground. According to researchers, they form in the summer about 50 miles high in the sky. They’ve been seen as far back in time as the 1800s, but their reports are becoming more frequent, possibly because of global climate change thanks to increasing amounts of greenhouse gases in the atmosphere.

Want to see a variety of photos of noctilucent clouds? Check out this website of such clouds seen in Europe.

In fact, you can’t see the clouds during the daytime. They only begin to appear at dusk when most sunlight is gone, but some sun rays can still illuminate that high clouds that are floating along the edge of space.

A theory for why noctilucent clouds are more regularly appearing is that greenhouse gases are deflecting heat from the highest levels of the atmosphere. That allows more ice crystals to thrive at that level and form into these special clouds. That same principle also may be deflecting more moisture into the upper atmosphere, providing more material for the clouds to form with.

This past spring NASA launched a special satellite to watch and gather data about these growing cloud formations. The project is called AIM – Aeronomy of Ice in the Mesosphere.