Global Cooling, Global Warming
Aug 8 at 2:02pm by Aileen
Researchers from Oregon State University and other institutions have published an article in the journal Science that they say puts to rest a long scientific debate on the causes of periodic ice ages in the history of our planet. The conclusion? Earth Wobbles.
The last major ice age reached its peak about 26,000 years ago, held steady for about 7,000 years, then began melting 19,000 years ago. The melting was caused by an increase in solar radiation, the researchers say, and not by carbon dioxide’s “greenhouse” effect, or any changes in ocean temperatures. These mechanisms have been cited recently by some scientists trying to understand what appears to be happening now with the increase in global temperatures termed “Global Warming” and said to be caused primarily by pollution from human activities.
The researchers analyzed 6,000 dates and locations of ice sheets to define when they started to melt. This confirmed a theory developed more than fifty years ago that held small but definable changes in Earth’s rotation as the trigger for both the accumulation of ice and its melting cycle. Putting that together with changes in the Earth’s axis and rotation going back 50 million years, they found that the gravitational influences of the larger planets – primarily Saturn and Jupiter – leads to predictable cycles.
Right about now, the scientists say, we should be changing from an interglacial period toward conditions that will ultimately lead to another ice age. That is, if human contributions to Global Warming don’t thwart the process. Meanwhile, a close look at plans to mitigate global warming with ‘Geoengineering’ suggests that such plans may well do more harm than good.
Research presented at a symposium at the Ecological Society of America’s annual meeting concludes that geoengineering is potentially dangerous, and that the risks outweigh the benefits. Plans such as limited nuclear detonations and subsequent fires to release lots of carbon into the atmosphere, seeding the atmosphere with light colored sulfur particles to mimic gigantic volcanic eruptions, and seeding the oceans with iron to increase carbon uptake all come with side-effects that could be disastrous, ecologists say.
Indeed, if we are starting to ‘wobble’ to the gravitational tune of our giant planetary neighbors toward another ice age, taking big efforts to cool the planet right now could actually speed up the process! Perhaps we should put off the big projects until we know more about all this, eh?
Popularity: 57% [?]
Forest Management vs. Carbon Sequestration
Jul 13 at 3:03pm by Aileen
If you or someone you know has chosen to live in or surrounded by forest – or just maintains a vacation cabin in such a setting – you are probably aware of the threat that wildfires present to property in those settings. And as the population has spread in many states out into more forested regions, many states and the federal government have undertaken forest fire prevention efforts to lessen the impact of such fires.
In the Pacific Northwest and elsewhere plans for fire prevention have included the idea of fuel reduction. This means thinning the forests and eliminating much of the understory growth. A recent study from Oregon State University sought to quantify the carbon sequestration and CO2 impacts of such a plan, and how these things affect global climate change.
Forest Fire Prevention Efforts Could Lessen Carbon Sequestration, Add to Global Warming details the issues and the report. The report’s authors came to a somewhat surprising conclusion:
“If fuel reduction treatments are effective in reducing fire severities in the western hamlock, Douglas-fir forests of the west Cascades and the western hemlock, Sitka spruce forests of the Coast Range, it will come at the cost of long-term carbon storage, even if harvested material are used as biofuels.”
The idea of using the plants and trees removed from the forest to lessen fire severity as raw material for biofuels was previously thought to offset the carbon sequestration costs of taking those trees. But it turns out that the production of biofuels isn’t very fossil fuel efficient and that the amount of energy returned doesn’t add up to the amount of energy used.
The kind of material at issue that would be harvested from the forests doesn’t produce good biodiesel fuel, which is better produced from oil-crops and such. Woody trees and shrubs are best used to make ethanol, but that process isn’t yet efficient enough to offset itself.
Another recent OSU study concluded that if the old forests of the Pacific Northwest were left alone or managed exclusively to promote carbon sequestration, they could double the amount of sequestration in many areas, even triple it in some other areas.
Bottom line then appears to be that if you build your house or vacation cabin in the old growth forests of the PNW, you shouldn’t expect to have the state or feds manage that forest so your property isn’t at risk from forest fires. Still, to many people the time spent in such abundant natural surroundings is worth the risk.
Popularity: 59% [?]
About those Mammoths? …Never Mind.
Jan 27 at 8:08pm by Aileen
On the fifth of this month I posted Supernovae, Comets and Holey Mammoth Tusks, about a recently-developed theory with apparently lots and lots of confirming evidence, that purported to demonstrate the mass extinction of North American megafauna – wooly mammoths, giant bison, saber-tooth cats, etc. – was the result of effects from a supernova explosion 250 light years from earth, and a 10-kilometer wide comet produced that hit or exploded just above Chicago nearly 13,000 years ago.
Well, this week researchers from the University of Bristol say they have disproven that theory, by examining charcoal and pollen records for the great fires the comet must have caused. Their results, they say, provide no evidence of continental-scale fires. Though they do say their examination of this material dated between 15,000 and 10,000 years ago, somehow establishes that an increase in large-scale wildfires all over the world during the past 10 years is attributable to global warming.
Ah, well. So much for grand theories about great and sudden climate change in past ages, as well as ongoing disagreements about climate change in the current age. Perhaps what is best to be learned from this back and forth of disagreements about evidence and what it means is to take the pronouncements of various groups of scientists with a grain of salt, for their conclusions are often so short-lived as to not even make it past the publication schedule of two successive issues of the same journal!
Eventually, maybe, they’ll work it all out.
And while we’re here looking at research from different sources that can end up with entirely different conclusions, check out a new project site from Creative Commons – ScienceCommons. Making the Web work for science, to develop technologies to make research, accumulated data and materials easier to find and use. I’ll be reporting on this again in the near future, so stay tuned!
Links:
Supernovae, Comets and Holey Mammoth Tusks
North American Comet Impact Theory Disproved
ScienceCommonsPopularity: 37% [?]
Barack Obama Answers the Science Questions
Aug 30 at 11:11pm by Aileen
Democratic Presidential candidate Barack Obama has submitted his Answers to the Top 14 Science Questions facing America. Drawing on the expertise of a squadron of science, economic, foreign policy and educational advisors that includes several committed Nobel Laureates, many will be happy to get the religious and political ideology out of the way and really start addressing these issues.Please go to the ScienceDebate 2008 website, take a hard look at Obama’s answers for our future, and don’t forget to drop the crew a dime (or ten) on your way out. These folks have been hard at it since November of last year, and have gathered some very impressive institutional support. The future is important to all of us – and our children – and the future needs the very best science we can possibly field to meet it head-on.
Popularity: 45% [?]
The ’08 Farm Bill and Improving America’s Diet
Jun 2 at 4:04pm by Aileen
The 2007 Farm Bill – now the 2008 Farm Bill, was passed by both chambers of Congress, vetoed by President Bush, then the veto was overridden by both houses and is now the ‘Law of the Land’. Politically, the bill isn’t perfect, there is still too much pork and payments to rich agribusiness concerns for their poor farming practices, and not enough clarifying guidelines for biofuels production and organic farming.
But it’s a lot better than no bill at all, which would have kept the last support bill in place for the foreseeable future. The new bill has incentives to clean up residue discharges in important watersheds, and supports for best practices in crop rotations, cover crops and low-chemical input farming. It’s still strong on commodity production (corn, wheat, rice), but does put some real support into farmer’s market promotions and expansion of organic markets. It does somewhat limit subsidies to near-millionaire commodity farmers, requires more fresh fruit and vegetables to be available in schools, increases food stamp benefits as tied to the price of food, allots priority funding to research into the bee die-off situation, and supports rural enterprise and microenterprise investments.
Research into the “typical American diet” and its relationship to serious health issues and obesity informs us that Americans eat way too much junk and not nearly enough healthy food. Which, in a country that rations health care by income level and allows insurance companies to exclude people who actually need health care, would seem to be an important issue to address with education and real food availability in public institutions such as schools.
Read the rest of this entry »Popularity: 38% [?]
What Happens To Your Anti-Bacterial Soaps
May 20 at 5:05pm by Aileen
The “germ-free” craze not only contributes to a generation of homebound children who have no developed resistance to real world ‘germs’ or irritants, we’ve also been warned over and over again for more than a decade that those bacteria we’re fighting will themselves develop resistance to the anti-biotics we use against them. Now a study by the Biodesign Institute at Arizona State University has traced the active ingredients in antibacterial soaps to their final resting place in the shallow sediments of estuaries into which treated wastewater is dumped.
The active ingredients traced are triclosan (TCS), which is structurally similar to dioxin, and triclocarban (TCC), a closely related compound. Biodesign Institute researcher Rolf Halden and coworkers traced these compounds to the shallow sediments of New York City’s Jamaica Bay and the Chesapeake Bay, the world’s largest estuary. Both of these compounds operate as endocrine (hormone) disruptors in mammals, much as agricultural chemicals operate to disrupt the sexual development of amphibians in the midwest.
Halden made use of concentrations of radioactive fallout from nuclear testing in the last half of the 20th century to determine how long ago the antimicrobial residues were deposited (and thus how long they’re lasting in the environment). And while core samples determined that a 1978 improvement in a Baltimore waste treatment plant did drop the levels of deposited TCC, the upgraded technology just put more of the substance into the sewage sludge that is disposed of by being applied as “fertilizer” on agricultural cropland.
Halden is planning to continue his research and study body burdens and health effects in pregnant women, nursing mothers and infants. Ecologically speaking, we are probably better off living with a few germs, and hand washing with regular soap has been shown to be just as effective as with antimicrobial soaps in sanitizing hands. Yet another good reason to reconsider our fear of germs – sometimes, it seems, the cure is worse than the disease.
Popularity: 20% [?]
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