And yet another reasonable statement that in the end seems to me to overstate (unless one thinks he intentionally used ³predicted² to mean something different than ³projected²):
³And even at a miniscule scale engineering the climate remains a radical step with consequences for both the climate and civilization that cannot be predicted in advance.² It seems to me there is far greater likelihood of getting reasonable projections of the effects of ³miniscule scale engineering² (well, if they would indeed be above the noise given he says miniscule) than of the details of large-scale human-induced climate change. And if doing both, it is not clear to me that the uncertainty of the projections of human-induced climate change with climate engineering would be greater than of the projections of human-induced climate change without climate engineering. There are good reasons for climate engineering, once researched, not being more than a last ditch option, but it seems to me those arguments are other than it being more uncertain. Mike On 12/12/14 5:23 PM, "Andrew Lockley" <[email protected]> wrote: > http://www.scientificamerican.com/article/fact-or-fiction-geoengineering-can-s > olve-global-warming/ > > Fact or Fiction?: Geoengineering Can Solve Global Warming > > Neither blocking sunlight nor capturing carbon can stop climate change > > December 12, 2014 > By David Biello > > A global deal to combat climate change lurches toward reality in Lima, Peru, > this week‹and yet any politically feasible agreement will be insufficient to > restrain continued warming of global average temperatures, perhaps > uncomfortably high. Although recent pledges by China, the 28 countries of the > European Union and the U.S. are the first signs of the possibility > of restraining the endless growth of greenhouse gas pollution on a long-term > basis, atmospheric concentrations of carbon dioxide have crossed the threshold > of 400 parts per million‹and will reach 450 ppm in less than two decades at > present growth rates. The estimated one trillion metric tons of carbon the > atmosphere can absorb could be burned through in even less time, particularly > if India, as it develops, picks up where China leaves off by burning coal > without any attempt to capture the CO2 before the greenhouse gas spews from > smokestacks. The world may find itself in need of another alternative, such > as geoengineering, if catastrophic climate change begins to manifest, whether > in the form of even more deadly heat waves, more crop-killing droughts, more > rapid rises in sea level or accelerating warming as natural stores of > carbon‹such as the ocean¹s methane hydrates‹melt down, releasing yet more > greenhouse gases to drive yet more climate change. So maybe the answer is to > genetically soup up plants so they can pull more CO2 out of the air and then > bury them at the sea bottom? Or give the planet a giant sunshade, whether in > the form of more clouds or a haze of light-reflecting sulfur bits floating in > the stratosphere? "In a crisis the temptation will be to use the quick fix of > geoengineering," argued economist Scott Barrett of Columbia University at a > research symposium on CO2 capture technologies this spring. If civilization > continues, the unplanned, undirected geoengineering of the climate via burning > fossil fuels‹whether coal in a power plant or oil sludge in a massive > container ship steaming across the Pacific‹then perhaps nations will need to > plan for a directed attempt at geoengineering or the "deliberate, large-scale > manipulation of the planetary environment" as the U.K.'s Royal Society defines > it. Still, scientists are starting to agree that geoengineering will prove > insufficient for solving climate change. To understand this it helps to think > of two distinct flavors of climate engineering: those that reduce greenhouse > gases and those that block sunlight to keep the planet cool. The various > sun-blocking schemes could be fast and cheap, like a fleet of airplanes > spewingsulfur particles in the stratosphere to mimic the cooling effects of > volcanic eruptions or an armada of ships brightening clouds by increasing the > number of water droplets within them. On the other side, carbon removal > schemes are slow and expensive, such as big air filters to suck CO2 out of the > sky and bury it, turn it into fuel or otherwise keep it from trapping heat. Or > the natural processes of rock weathering and plant growth that over geologic > time constrain climate change could be sped up. The Intergovernmental Panel on > Climate Change in its most recent comprehensive report suggested that one > member of this set of ideas‹burning plants paired with CO2 capture and burial, > aka bioenergy with carbon and capture, or BECCS‹might prove vital to restrain > global warming. And the U.S. Department of Agriculture provided a $91-million > loan guarantee in October to a company‹Cool Planet‹looking to build a kind of > BECCS facility in Louisiana to make biofuels and biochar, a carbon-rich > residual ash that can be used to improve soil fertility, keeping the carbon > out of the atmosphere. But neither flavor of geoengineering can serve as a > solution to climate change. > > As outlined in the December Philosophical Transactions of the Royal Society > A, sun-blocking schemes require continual refreshing and, at best, only buy > time for real solutions, such as cutting down on the amount of CO2 piling up > in the atmosphere as a result of fossil fuel burning, while failing to account > for other impacts such as the increasing acidity of the oceans. And CO2 > removal schemes could find themselves in a continuous game of catch-up with > the world's voluminous output of greenhouse gases‹an ever-more onerous burden > if the world did nothing to restrain global warming pollution. Geoengineering > could play a role in coping with some of the impacts of climate change, > perhaps used to cool off the rapidly warming Arctic and save summertime sea > ice. Or "these strategies might be used throughout the period required to > replace fossil fuel burning with globally distributed clean energy and even be > continued while CO2 concentrations remain too high," as atmospheric scientists > put it in an overview of the Philosophical Transactionsissue. Small-scale > tests of such techniques are therefore warranted to assess the real risks, > such as unexpected chemical reactions with the existing mix of atmospheric > gases, for example. Of course, it took massive emissions of CO2 to detect > human-caused global warming, suggesting small-scale tests may not reveal much. > And even at a miniscule scale engineering the climate remains a radical step > with consequences for both the climate and civilization that cannot be > predicted in advance. There is no technological fix for global warming other > than the hard work oftransforming a global energy system that relies on > burning fossil fuels into one that relies on energy sources‹the sun, Earth's > heat, fission or, maybe some decade, fusion‹that do not use the atmosphere as > a dump. The fact that geoengineering cannot suffice is good news because it > means that a viable form of climate engineering cannot undercut the urgency of > making that switch. No form ofclimate engineering can solve global warming at > present. To think so is science fiction. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
