NO PULITZER FOR USA TODAY, CZICZO RATES A ZERO 1. No acid rain problem, but journalists don't seem to care. Why let the facts get in the way of a bad story.
2. In defense of John Holdren (imagine that, me actually defending somebody!!), he was still acting and speaking like he was head of WHOI and AAAS and not as a spokesman for the WH. Pielke, Jr. took him to task for not checking his name badge before talking to Borenstein, and it is a little embarassing when you have to explain what you really meant to say (Holdren's clarification) and someone else issues a PR also explaining what you meant to say (the WH knee jerked on that one,) but I find Holdren a refreshing change from science hostages like former Science Advisor John Marburger, reduced to reading talking points scripted by policy hacks. I agree that the Administration should speak with one voice, but let's not go the hand-up-the-back-of- the-puppet route so early. 3. The fact that lead is an effective CCN doesn't mean it IS significant as a CCN. The clouds discussed are also in the lowermost stratosphere, not the overworld (above 53,000 ft) and have little to do with use of stratospheric aerosols for geoengineering. Most of the CCN for stratospheric aerosols are meteoritic in origin (they came from Outer Space, not leaded gasoline!!!!). There is also no evidence that ice clouds were more abundant when leaded gasoline was widely used. The last paragraph is simply ridiculous. On Apr 20, 5:06 pm, Dan Whaley <[email protected]> wrote: > Fairly unbalanced reporting here.... > > http://www.usatoday.com/tech/science/columnist/vergano/2009-04-19-geo... > > Scientists weigh geoengineering in global warming battle > By Dan Vergano, USA TODAY > Not every crazy idea, say dropping out of Harvard to start a software > firm, is a bad one. But you don't have to be Bill Gates to place your > bets that way. > > Consider atmospheric geoengineering — pumping reflective particles > into the stratosphere to reflect sunlight — seen as a way to cut the > effects of global warming. In 1991, the eruption of Mt. Pinatubo in > the Philippines cooled the atmosphere's average temperature worldwide > almost one degree Fahrenheit, a kind of "global dimming," serving as > an inspiration for the idea. Such high-altitude aerosols, different > from the ones found in spray cans, can play a big role in climate. > > A 2006 paper in the journal Science, for example, written by the > eminent atmospheric scientist Tom Wigley of the National Center for > Atmospheric Research, suggested that annually blasting roughly 500,000 > tons of sulfur (about 7% of yearly sulfur production) into the > stratosphere every year for three decades would prevent global > warming. But there is that acid rain issue. > > Earlier this month, White House science adviser John Holdren found > himself at the center of a brouhaha over remarks to the Associated > Press that geoengineering of all sorts was "mentioned" as the > administration pondered means of limiting global warming. Holdren > later downplayed geoengineering schemes, after news stories appeared > linking atmospheric geoengineering to drought, ozone depletion and > acid rain, among other concerns. > > A pair of recent papers point to some unintended consequences of > atmospheric geoengineering, ones that add to the sense that it might > not be such a good idea. > > In a study in the journal Environmental Science and Technology, > federal scientist Daniel Murphy of the National Oceanic and > Atmospheric Administration looked at what stratospheric aerosols would > do for solar cells and mirrored solar power collectors. He turned to > 1991 data from the Mt. Pinatubo eruption for an answer. > > In the study, calculations of sunlight scattering combined with > records from Hawaii's Mauna Loa observatory showed that for every one > watt's worth of sunlight reflected away from Earth by stratospheric > aerosols, another four watts were converted from direct sunlight to > diffuse sunlight. Such sunlight is bad news for the large power- > generating solar collectors that rely on mirrors to concentrate power. > Even though total direct sunlight fell only 3% in 1991, power > generated by these collectors dropped by 20%. "It turns out that any > systems using mirrors to concentrate direct sunlight are much more > sensitive than one-for-one," Murphy says, by e-mail. > > "Among all of the possible side effects of geoengineering, the effect > on solar power is probably not the most important. It is one of the > most certain," Murphy adds. > > A second paper, out Sunday in the journal Nature Geoscience, points to > another problem with stratospheric aerosols. "We are really uncertain > about their role in the climate system," says study lead author Dan > Cziczo of Pacific Northwest National Laboratories in Richland, Wash. > Ice condenses around aerosol particles, a process that scientists know > leads to high-flying cirrus clouds. Those clouds in turn reflect > sunlight, a cooling effect in the global warming equation. > > But how this happens exactly isn't clear, Cziczo says. "So, what we > were really trying to do was look at what particles helped to form the > clouds," he says. "What really cropped up was lead." > > In a series of field measurements of ice crystals combined with cloud > chamber experiments, Cziczo and colleagues found that lead makes a > great ice condenser in stratospheric aerosols, a first report of this > effect. > > "Most of the lead in the atmosphere is not natural," Cziczo notes, but > was spewed out in leaded gasoline in previous decades and is still > used in light aircraft engines. Lead is one of the worst pollutants of > the industrial age, linked to lowered intelligence scores, nerve > damage and high blood pressure, among many other ills. > > But plugging lead into a series of climate models, the Nature > Geoscience study shows that high stratospheric lead levels would lead > to ice clouds whose sunlight reflection would cut current global > warming in half. "These are the kinds of emissions we might have seen > in the late 1970's," Cziczo says. In past decades, lead pollution may > have helped keep global warming at bay. > > "The study helps to highlight why talk of geoengineering is something > we shouldn't pursue now," he adds. "It's a bit arrogant to presume we > understand aerosols so well we could not expect unintended > consequences." --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
