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Thursday, August 31, 2006

How are your water skills?

No, this doesn't have anything to do with swimming but you may still win recognition for your good ideas when it comes to conserving this most precious commodity...water. Under our environmental contests feature:

The Chartered Institute of Water and Environmental Management (CIWEM) is looking for those at the top of their trade - or with a promising future ahead of them - to put themselves forward for a series of awards.

CIWEM and the RSPB are looking for entries for their Living Wetlands Award, given to those who demonstrate sustainable management of wetlands.

The institute's World of Difference award rewards environmental scientists and engineers for, focusing on innovative design in water and wastewater projects.

The CIWEM Young Members' Award, recognises the outstanding contribution to environmental understanding made by a young member of the institute.

Full details of these and other awards can be found on the CIWEM website.

by Greener Mag

Top of Page

9:24 AM

Katrina cottages available this fall

After announcing that it would become the retailer of plans and materials needed to construct Katrina Cottages, Lowe’s joined forces with designer Marianne Cusato and Mississippi Gov. Haley Barbour on Tuesday for a “board cutting” ceremony and press conference in Ocean Springs, Mississippi. During the ceremony held even as hurricane Ernesto turned onto the Florida mainland officials unveiled the first-of-its-kind Lowe’s Katrina Cottage.

The cottage, which showcases 544 square feet of livable, decorated space, is a permanent and weather-resistant housing solution for Gulf Coast residents who are rebuilding their homes and communities in the wake of Hurricane Katrina. Although not hurricane proof, desigers pointed out that the structure of the cottages was held to the highest standards of storm resistence. sometimes called the "Boca" standard.

Lowe’s Katrina Cottages, developed by Marianne Cusato in conjunction with a team of leading architects from around the United States including renowned architect and town planner Andres Duany, are designed to withstand heavy rain and winds up to 140 miles per hour, meet most hurricane codes and the International Building Code. The plans and building materials for the cottages will be available for purchase at select Lowe’s stores, initially in Mississippi and Louisiana, beginning this fall.

by Harlan Weikle
Greener Magazine

Additional reading:: Read our exclusive interview with Katrina Cottage Architect Marianne Cusato earlier this year

Comments 1:

    Great cottage design. I wish we could foster small house
    designs like that for the rest of us who live in apartments and can't
    afford the astronomical California real estate prices. We need to
    think smaller, and reduce our drain on the world. I was thinking this
    morning, I wonder how our "carbon footprint" compares to our parents'.
    And we have so many more people, too! Yowsers! Mother Earth, I feel
    for you! Carolyn - Playa del Rey, CA

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7:23 AM

Wednesday, August 30, 2006

Aftermath Katrina, the "right to return"

One year after Hurricane Katrina's floodwaters nearly destroyed the region, virtually nothing has been done to reconstruct the Crescent City. Inaction from local authorities, almost zero commitment from the federal government, material shortages and employers leaving workers unpaid, have all added up to a crisis of stagnation and desperation for residents trying to reestablish their lives. Rebuilding must happen, but who will do the building? Some say a new union movement is the answer.

In addition, many of Katrina's refugees assert the "right to return" as part of the deep historical relationship African-Americans have to land in the south. On this edition, we'll hear from three community organizers. Listen now...


Steve Zeltzer, founder, Labor Video Project; CC Campbell-Rock, veteran journalist and community organizer displaced by Hurricane Katrina; Raymond Rock, community organizer displaced by Hurricane Katrina; Eric Mann, author and director, Labor Community Strategy Center.

by NRP The National Radio Project
Greener Magazine

Senior Producer/Host: Tena Rubio.
Mixing Engineer: Phillip Babich.

For more information:

C.C. Campbell-Rock
c/o San Francisco Bay View
National Black Newspaper
4917 Third Street
San Francisco California 94124

The Labor Community Strategy Center
3780 Wilshire Blvd., Suite 1200,
Los Angeles, CA 90010
213-387-2800; Fax: 213-387-3500

Labor Video Project
PO 720027
San Francisco, CA 94172
lvpsf@igc.org or lvpsf@labornet.org
www.labortech.net or www.labornet.org

Labor Fest 2006

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2:09 PM

Protecting the coast, post-Katrina

In the year since the levees broke in New Orleans, scientists and engineers have found a lot of reasons for hope and despair about the future of Louisiana's coast.

The good news is that the solution may be in the Mississippi River itself.

The bad news is that some coastal areas, including New Orleans, could be sinking a lot faster than expected. Maybe too fast. Or maybe not.

First there's that murky Mississippi water. Mark Twain, who had a stint as a Mississippi riverboat pilot, reported that a glass of the fresh muddy river water was once considered "wholesomer to drink" than clear water of the Ohio River on account of the "yaller" mud.

In fact, each year the great river carries about 100 million tonnes per year of silt, sand and gravel through engineered channels, past New Orleans and into the depths of the Gulf of Mexico.

That's equivalent to 10 Superdomes packed tight with dirt, each year, says Denise Reed, professor of geology and geophysics at the University of New Orleans, who has been working on finding solutions for the coast.

Year in and year out, 100 million tonnes adds up to a whole lot of real estate flowing freely right into, then right out of, a place that is losing land at more than 120 square kilometres each year.

"Here we are, going cap-in-hand to Congress for money when our most valuable resource is being wasted," Reed says.

If, instead of being artificially channelled to the southernmost tip of the Mississippi Delta and dumped into deeper waters, most of that muddy water sediment were allowed to flow into the shallow surf zones further north, it would get caught up in the never-ending shoving match between the river and the sea.

Once there, as is the case along any shoreline near a river, ocean waves would serve as nature's free earth-moving machines and build up beaches that could protect the land from storm surf.

It's the very process that built the Louisiana coast in the first place, Reed says.

"The mother lode is still being wasted," she says. "We have got to keep it in the shallow water."

Muddy process

So just what kind of project would keep that liquid real estate in Louisiana, while at the same time protecting homes and cities, maintaining a navigable river and restoring the troubled Mississippi Delta wetlands?

That question is now the focus of feverish discussion and planning by Louisiana's brand-new Coastal Protection and Restoration Authority, or CPR Authority, says Robert Twilley, a professor of wetlands biogeochemistry at Louisiana State University (LSU).

Back in November, just two months after Katrina, the Louisiana State Legislature created the CPR Authority by blending together the state Department of Natural Resources and the state Department of Transportation and Development.

What this means, says Twilley, is that for the first time protection, which usually means buildings, is being integrated with restoration, which usually refers to coastal wetlands.

For decades the two goals have been largely perceived as opposites.

"It completely changed overnight our bedfellows," says Twilley. "It really has, in the last year, focused a very clear discussion on levees and wetlands as an integrated protection system."

The CPR Authority's first daunting task is to work with the various levee boards and the federal government to craft a comprehensive protection and restoration plan for the Louisiana coast.

The plan is to be gleaned from vast amounts of data and delivered to the public in January, Twilley says.

Muddy mystery

One of the most slippery and yet fundamental aspects of all that modeling and planning is figuring out subsidence, or just how fast the Louisiana coast is sinking and whether there is anything we can do about it.

Just as Katrina struck last year, scientists were in the midst of a stormy debate over subsidence, Twilley recalls.

Rates of subsidence now range from just less than a millimetre per year to 170 times that rate.

Geologists know of at least three things that could be causing the ground to sink lower along Louisiana's coast.

One is the extraction of oil, gas and water from the ground, which was implicated last year in a US Geological Survey report.

Another is the somewhat limited natural settling and compaction of river sediments that make up the ground.

Lastly, there are deeper 'tectonic' changes involving the rising and falling of shifting large blocks of real estate along faults, the sort of thing that's more common in fault-ridden places like California.

In April, Twilley's LSU colleague Professor Roy Dokka came out with a paper in Geology, in which he argued that faulting and what looks like a gigantic, slow-moving regional landslide is the cause of almost three-quarters of New Orleans' subsidence.

Dokka revised regional elevation data using precision Global Positioning System equipment and discovered a higher rate of subsidence over the past 50 years is almost all caused by this tectonic movement.

Then in July Geology published a paper by Tulane University's Associate Professor Torbjörn Törnqvist, who used an entirely different approach.

Törnqvist surveyed long-buried wetland peat layers in outlying areas to come up with entirely different and milder subsidence rates.

"I think there is a very balanced dialogue going on," says Twilley of the two studies. "I have a lot of respect for both of them."

It's just the way science works, agrees Reed, and it's not surprising, considering that the two studies are so different in methods and the places they examined, she says.

Discovering the truth about subsidence is going to take a lot more work and a great deal of time, all of which Dokka, Törnqvist and others are already investing at top speed.

Like the people of the CPR Authority, the Army Corps of Engineers, the levees boards and everyone else along the Louisiana coast, the subsidence researchers are urgently looking for answers so planners can make the right decisions and everyone can get to work before another Katrina-sized storm comes anywhere near.

"The problem is," says Twilley, "it takes a lot of time, and time we don't have."

by Larry O'Hanlon
Greener Newsroom

Top of Page

11:43 AM

Tuesday, August 29, 2006

Ozone recovery slows

The ozone layer is recovering, but not as fast as scientists had optimistically predicted in the past, the World Meteorological Organisation has said following a major report on progress made since the Montreal Protocol.

photo credit: Central Intellegence Agency

Ozone depletion is particularly severe over the Antarctic

Most stratospheric ozone is set to return to its undamaged pre-1980s state by 2049, according to the Scientific Assessment of Ozone Depletion: 2006 report produced by over 250 international experts, and published jointly by UNEP and the World Meteorological Organisation.

The last such assessment, dating back to 2002, had put the expected date for complete recovery five years earlier. What has changed since then, it seems, is that scientists have realised that estimates of how much ozone-depleting substances we are yet to pump out into the atmosphere had been over-optimistic.

The 1987 Montreal Protocol has been effective in cutting out the use of ozone-depleting substances - especially the CFCs used in refrigeration and air conditioning - with atmospheric concentrations of these substances now falling.

Despite these positive developments, it now turns out that scientists had underestimated the amount of CFC-11 and CFC-12 still present in fridges around the world, which will eventually make their way into the atmosphere and inevitably do their damage to ozone.

While the recovery date for most of the ozone has now been revised from 2044 to 2049, predictions for the Antarctic are worse still, with the recovery not expected until 2065 - 15 years later than once expected. Ozone depletion in the Antarctic is particularly severe, and the report's authors put the longer recovery time down to the "greater age of air in that region," which concentrates ozone-depleting substances and magnify the damage they cause.

"While these latest projections of ozone recovery are disappointing, the good news is that the level of ozone-depleting substances continues to decline from its 1992-94 peak in the troposphere and late 1990s peak in the stratosphere," said Michel Jarraud, secretary-general of WMO.

"Global changes in climate suggest that atmospheric conditions are different today from those prior to periods marked by ozone depletion. This may have implications for ozone recovery. Maintaining and improving observational and assessment capabilities are critical in separating effects due to changes in climate from those in ozone-depleting substances and will play a major role in verifying the effectiveness of actions taken under the 1985 Vienna Convention, the 1987 Montreal Protocol and its amendments."

"The early signs that the atmosphere is healing demonstrate that the Montreal Protocol is working. But the delayed recovery is a warning that we cannot take the ozone layer for granted and must maintain and accelerate our efforts to phase out harmful chemicals", said Achim Steiner, executive director of UNEP.

by Goska Romanowicz
Greener Newsroom ::

Further reading:: UNEP United Nations Environment Programme
and WMO World Meteorlogical Organization websites.

Top of Page

12:36 PM

NOAA satellite: Ernesto 8/29

The latest satellite images of Ernesto as it crosses Cuba and begins to reform over the Florida Strait, south of Miami::8:07 AM 8/29 Greener Weather/NOAA

Click to view

Greener Magazine::

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8:05 AM

Sunday, August 27, 2006

European Space Agency, Ben and Jerry's study climate change

Following the loss of the European Space Agency's CryoSat Mission during launch last October the mission has been re-scheduled for early 2009.

CryoSat is designed to map variations in ice thickness at the earth's poles over a 3 1/2 year study. The fine scale measurements - to within centimeters - will help scientists establish possible trends in the growth and shrinkage of the ice caps, which in turn may reveal in more detail the processes fueling global warming.

Students at The University of Aberdeen, King's College are preparing ground studies in collaboration with ESA and this summer students from the Climate Change College, sponsored by Ben and Jerry's and the World Wildlife Fund, have completed a series of climate studies in the Artic, which will help calibrate CryoSat's data as it is recieved. ESA's CryoSat Mission planners hope to answer the question of whether global climate change is causing the polar ice caps to shrink, one of the most hotly debated environmental issues we currently face. By monitoring precise changes in the thickness of the polar ice sheets and floating sea ice, CryoSat-2 may at last begin to shed light on earth's changing climate.

by Harlan Weikle
Greener Magazine

More on CryoSat::Video Talk

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12:12 AM

Wednesday, August 23, 2006

Waves of change, rivers of doubt: Global water issues

Water... it's the source of all life. 70 percent of the planet is covered in it, and more than half of your body is made up of it. We use water everyday to refresh, revive, to subsist... yet, water resources are growing increasingly scarce around the world and access to potable water is alarmingly difficult in some regions.

All life on this planet depends on water, a precious resource. Yet, we are struggling to manage water in ways that are efficient, equitable, and environmentally sound. Many parts of the world will face increasingly dire conditions as populations grow, cities expand, and sources of clean, fresh water disappear.

To avert damaging social and environmental outcomes, we need bold policy reforms. Perverse policies are the main cause of the waste and inefficiency that drive freshwater pollution and over-consumption. Reforming these policies requires governments to implement far-reaching institutional change and promote technical innovation.

. . . Turning ideas into action . . .
In this edition, we look at some core water issues affecting people around the world, including privatization, access to clean water, desalination technology, bottled water debates, and non-point source pollution. Listen now...

Kapua Sproat, attorney, Earth Justice; Duke Sevilla, co-founder and treasurer, Hui o Na Wai `Eha; Alan M. Arakawa, Mayor of Maui; Avery Chumbley, president, Wailuku Water Company; Wenonah Hauter, executive director, Food and Water Watch; Geoffrey Segal, director, Privatization and Government Reform/Reason Foundation; Chuck Swartzle, president, Besco Water Treatment, Inc.; William E. Lobenherz, Michigan Soft Drink Association; Dave Dempsey, Clean Water Action Great Lakes; Karl B. Stinson, operations manager, Alameda County Water District; Dr. Peter Gleick, director, The Pacific Institute; Richard Stover, Energy Recovery Inc; Conner Everts, director, California Statewide De-Sal Response Group.

by NRP The National Radio Project
World Resource Institute
Greener Magazine

Senior Producer/Host/Writer: Tena Rubio
Contributing Producers: Robynn Takayama, Lester Graham, Brian Edwards-Tiekert.

An hour-long version of this program is available on PRX at http://www.prx.org/pieces/13203

For more information:

Earth Justice
223 South King Street, #400
Honolulu, HI 96813-4501
808-599-2436; ksproat@earthjustice.org

Mayor, County of Maui
200 South High Street
Wailuku, Maui, HI 96793
808-270-7855; Fax: 808-270-8073

Wailuku Water Company
255 E Waiko Rd.,
Wailuku HI 96793-9355
808-244-9570; Fax: 808-242-7068

Hui o Na Wai `Eha
c/o John and Rose Marie Duey
575A Iao Valley
Wailuku, HI 96793-3007
808-242-8565; jduey@maui.net

Food and Water Watch
1400 16th Street NW, Suite 225
Washington, DC 20036
202-797-6550; Fax: 202-797-6560

Clean Water Action National Office
4455 Connecticut Avenue NW, Suite A300
Washington, DC 20008

Besco Water Treatment, Inc.

The Pacific Institute
654 13th Street, Preservation Park
Oakland, CA 94612

Energy Recovery Inc.
1908 Doolittle Drive
San Leandro, CA 94577

Top of Page

1:03 PM

Saturday, August 19, 2006

Global warming: Clearing up confusion leads to solutions

“Global warming… let’s see, it definitely has to do something with the sky… the ozone layer? No, carbon dioxide, or wait, carbon monoxide? Like from cars. And aerosol cans. Yeah, because that’s why they got rid of Freon. Right?”

If this sounds familiar, you’re not alone. The results of a recent focus group conducted by the David Suzuki Foundation reveal that most Americans are pretty hazy on just what global warming means. While they’re aware that it’s a growing concern, they’re hard pressed to say just how, or why.

Many folks, it seems, have confused the ozone layer with global warming, but in fact, they’re rather opposite phenomena. Ozone is a molecule found mostly in the earth’s stratosphere that shields the earth from ultraviolet rays. Certain free radicals released by human activity, such as CFCs (chlorofluorocarbons), break down ozone, thus creating a hole in this protective layer.

This has little to do with global warming, which is, rather, the creation of too thick a shield in the atmosphere. Greenhouse gases, like carbon dioxide, linger in the atmosphere surrounding the earth. Sunlight enters the earth’s atmosphere, strikes the earth’s surface, and radiates back out in the form of heat. Some of it escapes into space, but some of it bounces off these greenhouse gas molecules and stays close to the earth. To a certain degree, this is good – that’s why it’s warmer here than on the moon! But when human activity generates excess greenhouse gases, too much heat is trapped, causing the earth’s temperature to rise. That’s global warming.

Global climate change is a bit scary, but increased media coverage of global warming – particularly Al Gore’s new movie – has got people talking about solutions. After a Boston screening of An Inconvenient Truth, concerned viewer Elena W. vowed to get on the ball. “I should get some canvas bags so I can stop using the grocery store's,” she mused. “I think that's my first goal. I should also write to my town's politicians and ask them what's up with them not picking up my recycling. We don't have one of those plastic bins for the recycling, so instead I just put the recycling out in a paper bag, but the trash guys don't take it. I guess I better do something about that.”

Manageable, small changes are just what environmental activists encourage. Dr. Suzuki, of the DSF mentioned above, promotes ten of the simplest and highest-impact steps towards conservation, as part of his Nature Challenge:
1. Reduce home energy by 10%
2. Eat meat-free meals (at least) once a week
3. Buy a fuel-efficient, low-polluting car
4. Choose an energy-efficient home and appliances
5. Stop using pesticides
6. Walk, bike, or take transit to regular destinations
7. Prepare your meals with locally produced food
8. Choose a home close to regular destinations
9. Support alternatives to the car
10. Get involved, stay informed

While none of these things may appear obviously related to the situation in our stratosphere, they are more significant than you might guess. For more information on these and other steps you can take to reduce your greenhouse gas emissions, check out www.davidsuzuki.org.

by Sara Kate Kneidel
Greener Magazine

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11:35 AM

Wednesday, August 16, 2006

Environmental toxin continues to threaten vultures

Nearly 18-months after Indian officials banned the use of the pain killer diclofenac in farm animals residual amounts persist in the vulture population there. However, scientists are hopeful that, in time, all traces of the drug will disappear from the ecosystem ensuring the vultures continued survival.

photo courtesy: Allen Matheson

Debbie Pain, head of international research at the UK's Royal Society for the Protection of Birds RSPB) first called attention to the looming environmental disaster in January 2004 when she reported, “The decline of three raptor species of vulture across South Asia has been absolutely catastrophic,"

A year later the BBC in an Article March 2005 reported that a ban had been announced by Indian officials noting that: "Vultures hold a critical position in the food chain and are renowned for their ceaseless scavenging. But their once-abundant numbers have been in decline for more than a decade."

Our media partner, The Animal Broadcast Network reported that, recent evidence links the use of the drug diclofenac to manage pain in agricultural livestock to the dramatic decline in the populations of three species of vultures in Asia. Diclofenic is from a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). Diclofenac works by reducing hormones that cause inflammation and pain in the body."

Asian farmers began using the drug in livestock during the 90s and the resultant spread through the eco system has led researchers to conclude that it is the primary cause for the decline in vulture populations. Vultures fulfill their necessary role in the environment by scavenging dead animal carcasses and thereby over time accumulate toxic levels of dicofenac leading to kidney failure and ultimately, death.

In some areas, the decline has reached an alarming 99%, which puts the vulture at the top of the endangered species list. The resultant ripple effect through the system is the increase of other less desirable scavenger populations like feral dogs. An increase in the propagation of human diseases would follow.

This week, research publisher Science Daily has a follow up to the story Vultures at risk reporting that starting August 12, 2006, the production and importation of veterinary diclofenac is no longer permitted in India as conservationists continue their efforts to save the vultures from extinction.

by Nancy Lee
Greener Magazine

Update::Drug firm backs vulture recovery plan
16 August 2006
New Scientist
submitted by Chris in the UK

Editor's note:: Action for Amimals 2006 gets underway September 2nd in Washington DC. This is the second annual national conference sponsored by animal welfare groups and promises some great presentations and a special guest performance by songwriter, singer Nellie McKay.

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9:36 PM

Wednesday, August 09, 2006

Citizen soldier, citizen robot

The American army announced recently that it intends to have armed robots in the field, robots capable of lethal force.

The Pentagon which has long speculated on the development of robotic warriors has committed to a $127-billion project called 'Future Combat Systems' and plans to deploy small tank like bomb disposal robots capable of discharging offensive fire at the rate of 1000 rounds per minute.

Controlled by humans, these robot warriors are just the vanguard of the military's push to field an army of autonomous mechanized soldier specialists in an effort to, "spare human casualties." Military planners say that, in the beginning, robots will take many shapes and perform singular tasks like mine clearing and reconnaissance but, as the technology improves, the robot soldier will evolve to become largely self directed, more problematic and certainly more lethal; the era of the hunter-killer machine will have arrived, perhaps as early as 2035.

"A robot army could never be held morally responsible for committing war crimes," says an Australian ethicist, "and so any wars they fight could be considered unjust."

Dr Robert Sparrow of Monash University, who specialises in the ethics of new technologies, will lay out his argument in the Journal of Applied Philosophy.

by Harlan Weikle
Greener Magazine


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8:28 PM

BP turns off the oil, bacteria to blame

We first looked into energy giant British Petroleum 5 months ago as they struggled to minimize the effect of a small (250,000 barrel) spill at their head pipeline distribution center,Pipeline spill update. That spill went unnoticed for several days before being accidentally discovered during a routine maintenance inspection. The spill was quickly contained without interruption of service, which daily pumps nearly 200 thousand gallons of highly corrosive crude oil through its "feeder" lines to Alyeska, the Federally controlled and inspected main pipeline south. View our interactive satellite image of the Alyeska Pipeline where it spans the Yukon River.

The reason, the spill occurred when a small pinhole appeared in a 34-inch diameter pipe connecting one of BP's lesser pump fields, before the main pipeline starts south. The hole, the diameter of a pencil sprayed oil into a ditch, which slowly grew to form a small lake covering about 2 acres. The spill remained hidden covered by fresh snowfall.

Now it seems that BP once again has a problem with their aging pipeline this however potentially could become much more serious. Engineers inspecting the system discovered a large segment of the main trunk pipe had become dangerously corroded and threatened to burst. The pipes were intended to have a life span of 10 years, a period exceeded in some sections now by almost 4 years. To make matters worse the line now carries not the higher-grade oil originally pumped from Alaska's North Slope but rather a lower grade crude. The low-grade oil contains significant amounts of sediment and salt water, which accelerates corrosion in the pipeline - think of your car in winter.

A maintenance procedure called “pigging”, or firing a solid object called a “pig” down the pipe to clean its interior walls is a normal method employed by pipeline companies to remove the sludge, which builds up along the line and can lead to corrosion. Maintenance records indicate BP officials have restricted the use of “pigging” over the past few years in an effort to increase production and minimize down time. BP has now closed the pipeline for an indeterminate period, a shutdown that promises to send oil prices soaring, and may have a direct impact on California. Alaska supplies nearly 20 percent of the oil produced by California's refineries.

According to Bob Malone, Chairmain and President of BP America in an interview today on CNN, the problem arose when workers discovered a bacterial growth in the sludge collecting in those pipes. The bacteria he said, "secretes an acid", which is believed to have accelerated the corrosion. He would not speculate on a time frame for the planned repairs.

The good news is that, this time at least, an injury to the environment seems to have been avoided but the cost may still threaten future disaster if BP is not willing to ratchet back its egregious desire for triple digit profits at the expence of an effective, proactive maintenance program.

By Harlan Weikle
Greener Magazine

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1:44 PM

Friday, August 04, 2006

Weather makes Earth wobble

Scientists have confirmed that weather makes the planet wobble on its axis after exploiting a rare opportunity to detect and measure the most subtle shifts in the Earth's spin.

The wobbling at the poles was in the order of centimetres, from the size of a 25 cent piece to the size of a DVD, says astronomer Thomas Johnson of the US Naval Observatory.

"These loops are on the order of two or three days," says Johnson of the timeframe in which weather tugs and varies the direction Earth's axis is pointed in space.

To see the weather wobbles, Belgian researchers took advantage of an unusual period from November 2005 to February 2006 when two better known, larger components in Earth's wobble cancelled each other out and no longer drowned out the signal of the smaller wobbles.

The two larger components are a 433-day wobble thought to be caused by deep ocean current changes and annual wobble that corresponds to seasonal changes. These change the position of the poles on about the scale of a baseball diamond, says Johnson. Every 6.4 years they cancel each other out.

"It was basically now or never," says Sébastien Lambert of the Royal Observatory of Belgium of their well-timed measurements, which used GPS data to ferret out the weather effects."We would have to wait more than six years for another chance.

"Lambert and his colleague Véronique Dehant publish their findings in the journal Geophysical Research Letters.Lambert was also able to connect the specific wobbles seen during that period to atmospheric pressure systems over Asia and Europe. This connection makes it possible to use smaller wobbles is critical for navigational, timing and communication systems, says Richard Gross of NASA's Jet Propulsion Laboratory.

"We have to know how the Earth's rotation is changing in order to track a spacecraft," Gross explains. At distances of tens of millions of miles, a few centimetres on Earth can make the difference between communicating with the spacecraft and losing contact altogether. "It's most important when you are trying to land something on another planet," he says.

On Earth the weather wobbles are also important because they can throw off models that are used to predict and correct for the larger wobbles, multiplying errors in GPS and military navigational systems."The accuracy would be orders of magnitude worse" without these wobble corrections, says Johnson. "At the latitude of Reagan National Airport [near Washington DC], the variation could be the difference between a plane landing on the runway or hitting the Potomac River."The wobbles also have to be accounted for when finely tuning clocks and the timing of satellite communications."They all require Earth orientation data nowadays," says Johnson.

Larry O'Hanlon
Discovery News
Greener Newsroom

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4:47 PM