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EARTH TALK
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From the Editors of E/The Environmental Magazine
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EARTH TALK
Dear EarthTalk: Is there any link between increased volcanic activity—such as the recent eruptions in Iceland, Alaska and elsewhere—and global warming? -- Ellen McAndrew, via e-mail
It’s impossible to pin isolated natural phenomena—like an individual volcanic eruption—on global warming, but some researchers insist that there is a correlation between the two in some instances.
“Global warming melts ice and this can influence magmatic systems,” reports Freysteinn Sigmundsson of the Nordic Volcanological Centre at the University of Iceland. Her research with Carolina Pagli of the University of Leeds in England suggests that rocks cannot expand to turn into magma—the primary “feedstock” for volcanic eruptions—when they are under the pressure of a big ice cap pushing down on them. As the theory goes, melting ice caps relieve that pressure and allow the rocks to become magma. This in turn increases the chances of larger and/or more frequent eruptions in affected regions, from Iceland to Alaska to Patagonia to Antarctica.
As for Iceland specifically, the eruption of Mt. Ejyafjallajökull that shut down some air travel for weeks this past spring cannot be blamed on changing climate: That volcano lies under a relatively small icecap which would not exert enough pressure to affect the creation of magma. But Sigmundsson and Pagli found that the melting of about a tenth of Iceland’s biggest icecap, Vatnajokull, over the last century caused the land to rise an inch or so per year and led to the growth of an underground mass of magma measuring a third of a cubic mile. Similar processes, they say, led to a surge in volcanic eruptions in Iceland at the end of the last ice age, and similarly increased volcanic activity is expected to occur there in the future.
On the flip side, volcanic eruptions can exacerbate the ongoing effects of climate change: Already retreating glaciers can lose all their ice when something below them blows. Of course, many volcanoes around the world are not subject to pressure from ice caps, and scientists stress that there is little if any evidence linking global warming to eruptions in such situations.
Some have theorized that large volcanic eruptions contribute to global warming by spewing large amounts of carbon dioxide and other greenhouse gases into the stratosphere. But the amount of greenhouse gases emitted by even a large and ongoing volcanic eruption is but a drop in the bucket in comparison to our annual output of industrial and automotive carbon emissions.
According to the U.S. Geological Survey, greenhouse gas emissions from volcanoes make up less than one percent of those generated by human endeavors. Also, ash clouds and sulfur dioxide released from volcanoes shield some sunlight from reaching the Earth and as such can have a cooling effect on the planet. The 1991 eruption of Mt. Pinatubo in the Philippines—a much larger eruption than what occurred recently in Iceland—caused an average cooling of half a degree centigrade worldwide during the following year. Regardless, single volcanic eruptions, even if they last for weeks or months, are unlikely to send enough gas or ash up into the skies to have any long term effect on the planet’s climate.
CONTACTS: Nordic Volcanological Centre at the University of Iceland, www2.norvol.hi.is; U.S. Geological Survey, www.usgs.gov.
EarthTalk®, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk® is now a book! Details and order information at: www.emagazine.com/earthtalkbook.
EarthTalk®
From the Editors of E/The Environmental Magazine
Dear EarthTalk: It has been said that global warming will bring a new ice age. Is this true or only fiction? -- Nitisha Jain, Delhi, India
While no one can be sure what and how severe the effects of global warming will be, it is entirely possible that one outcome of our profligate use of fossil fuels could be an ice age. The theory goes that a warming-induced influx of cold, fresh water into the North Atlantic from melting polar ice caps and glaciers could shut down the Gulf Stream, an underwater channel of warm ocean water that winds its way north from the Caribbean and moderates temperatures in the northeastern U.S. and Western Europe.
The result, some scientists speculate, would be a return to ice age conditions. In the extreme, glaciers and freezing temperatures would render large swaths of the civilized world uninhabitable and would kill off untold numbers of species unable to move or adapt. A less dire version would still cause bitterly cold winters, droughts, worldwide desertification and crop failures, and trigger resource wars across the globe.
Of course, over the history of geological time the planet has endured vast shifts in temperature and many ice ages and subsequent warm-ups. The last major ice age peaked about 20,000 years ago, when extensive ice sheets covered large parts of what we now call North America, Europe and Asia. Many climate scientists believe the planet oscillates between warmer and colder periods without human intervention due to various factors related to its orbital path and also variations in heat output from the Sun on a millennial scale—and that we are naturally heading toward another ice age, regardless of greenhouse gas emissions, over the next several dozen millennia.
But others believe those very emissions might just save us from the freezing throes of another ice age. In a study published in the September 4, 2009 issue of the Science magazine, researchers report that human-induced climate change is quite possibly fending off what had been presumed to be an inevitable descent into a new ice age based on data collected across various Arctic regions in recent years.
The study found that after a slow cooling of less than half a degree Fahrenheit per millennium as a result of a cyclical change in the orientation of the North Pole and the Sun, the Arctic warmed by some 2.2 degrees just since 1900, with the decade from 1998 to 2008 the warmest in 2,000 years. Without human intervention, researchers would expect summer temperatures in the Arctic to cool for another 4,000 years or so as the North Pole gets further from the Sun, but in fact, researchers believe, global warming is reversing this trend.
“The slow cooling trend is trivial compared to the warming that’s been happening and that’s in the pipeline,” reports the study’s lead author Darrell S. Kaufman of the University of Arizona. Of course, only time will tell whether our relatively short-term flood of pollutants will have a pronounced long-term effect on the planet’s geological-scale warming/cooling dynamic. In the meantime, most responsible individuals and governments are working to lower their carbon footprints to try to take man back out of the climate equation once and for all. Hopefully our grandkids’ grandkids will be around to thank us.
Dear EarthTalk: What is the so-called “smart grid” I've been hearing about, and how can it save energy and money? -- Larry Burger, Litchfield, CT
America’s electricity grid is built upon what many consider to be an antiquated principle: Make large amounts of electricity and have it always available to end users whether they need it or not. It’s much like the way most home water heaters work in keeping water constantly hot even when it is not being used. It is also a strictly one-way relationship with utilities supplying power to end users, but not also vice-versa.
The smart grid concept is predicated on a two-way flow of energy—and information—between electricity generators and end users. The system not only delivers power to end users as needed, depending on demand; it also gathers power from end users that produce their own—homes and businesses that generate solar, wind or geothermal power themselves—when they have more than they need.
Some 42 states and Washington, DC already require utilities to have systems in place to buy excess energy generated by their customers. But, writes journalist Michael Prager in E – The Environmental Magazine, “because they can’t know in real time that power is coming in, utilities generate as much as they would have anyway.” He adds that when information flows both ways, end users will be able to send information back to the grid specifying how much power they need and when they will need it. They’ll also be able to communicate when they have excess power available to upload to the grid.
On the forefront of research into the feasibility of the smart grid on a large scale is the Future Renewable Electric Energy Delivery and Management (FREEDM) Systems Center, established in 2008 by the National Science Foundation and headquartered at North Carolina State University. FREEDM is partnering with universities, industry and national laboratories in 28 states and nine countries to develop technologies they say will “revolutionize the nation’s power grid and speed renewable electric-energy technologies into every home and business.” So far, some 60 utilities, alternative energy startups, electrical equipment manufacturers and other firms have signed onto the new partnership.
One such utility, Colorado-based Xcel Energy, has even begun to put smart grid technology into practice on a trial basis for a small percentage of its customer base. The utility has spent some $100 million outfitting 35,000 homes and businesses in and around the city of Boulder with automation and communications capabilities to enable two-way communication of electricity needs.
Xcel won’t have enough data to assess energy and cost savings until early 2010, but analysts are optimistic that the utility’s costly experiment will reap benefits down the road for consumers, utilities and the environment. Indeed, environmentalists and economists alike have high hopes that widespread implementation of such “intelligent” systems could help usher in a new age of unprecedented energy efficiency, emissions reductions and cost savings around the United States and beyond.
CONTACTS: Future Renewable Electric Energy Delivery and Management (FREEDM) Systems Center, www.freedm.ncsu.edu; Xcel Energy, www.xcelenergy.com
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