Posted by kelphead on July 16, 2001 at 18:49:30:
"Pitting Yankee Ingenuity Against Global Warming" by Usha Lee McFarling, Times Science Writer
Sunday July 15, 2001, L.A.Times, p.A1,A28.
"amsterdam--like life itself, the continuing debate over global warming has one thing at its center--carbon.
a buildup of carbon dioxide--the gas that is released from the burning of any form of carbon, from paper to petroleum--is the chief culprit in most explanations for the recent increase in global temperatures. to environmental activists and many political leaders in europe, the solution for that buildup is simple: use less. drive smaller cars to burn less gasoline. conserve electricity to burn less coal.
but for other political leaders, particularly the united states, who are reluctant to urge constituents to change their lifestyles or pay higher prices, another approach glimmers: find technological fixes to "manage" carbon.
"geo-engineering" is widely expected to be a major part of the proposals u.s. negotiators make in international talks that resume this week aimed at reviving the stalled kyoto protocol, a pact among developed nations to curb their carbon appetites.
"my guess is [that the bush administration] will put a lot of money into technology and hope for a magic bullet," said thomas j. crowley, an expert on climate change at texas a & m university.
some researchers see ideas for technological fixes as the application of good old yankee ingenuity to a major global problem. to others, it is folly--an idea that could easily worsen the problem as fix it.
because we do not fully understand all the mechanisms that regulate the earth's climate, even fairly low-technology ideas have potential to backfire, researchers say. for example, trees and other green plants absorb carbon dioxide through photosynthesis. knowing that, u.s. experts have suggested that planting large numbers of trees could offset carbon emissions.
but new research has suggested that in northern climes, new forests would replace snowy fields that cool the planet by reflecting sunlight back into space, said richard betts, a scientist at the hadly center for climate prediction and research in england. even in areas without snow, he said, forests are darker and absorb more energy than open fields. the net result might be to make the earth even warmer.
if such a simple method as planting trees might cause problems, critics ask what the risks of more exotic techniques could be.
"it's naive to say, 'we'll roll up our sleeves and come up with a good american solution,'" said ray weiss, a professor of geochemistry at the scripps institute of oceanography in la jolla who served as a scientific advisor to the u.s. delegation during the last round of climate talks. "we were supposed to do that with AIDS."
beyond planting trees, other ideas include squirting huge bubbles of liquid carbon dioxide into the bottom fo the sea, genetically engineering microbes to gobble greenhouse gases and fertilizing large swaths of ocean with supertankers full of iron so fields of carbon-eating plankton would bloom in now barren seas.
from fringe to center of debate
one of the leaders of this new work is peter brewer, an ocean chemist at the monterey bay research institute who has been experimenting with attempts to store liquid carbon dioxide on the ocean floor.
during the last five years, as the global warming debate has intensified, brewer has seen his work grow from an interesting but odd scientific proposition to a prospect at the center of both the clinton and bush climate-change agendas.
his group's experiments, published in the journal 'science' in 1999, show that it is possible to put liquid carbon dioxide at the ocean bottom. chemical reactions trap the liquefied gas into a kind of skin, an ice-like lattice called clathrate hydrate that keeps the gas, for a short time at least, in blobs that roll around on the sea floor.
a major concern is what the gas would do to marine organisms. adding carbon dioxide makes the seawater more acidic, and large amounts of the gas could suffocate fish by displacing oxygen in the water.
brewer's experiments, captured on film by a submersible-mounted camera, found that fish and sea cucumbers did not seem to mind the new addition. "we have fish coming up and looking at what we're doing--they're quite curious--and then moving on," said brewer in an interview from his lab at moss landing.
the liquid carbon dioxide does not sink like a billiard ball or stay contained in one place like a huge pond within the ocean. instead, it responds to the ocean's natural turbulence--floating, breaking up and gradually mixing into the water.
"the idea you could store CO2--that it would be there for a long time like a piece of ice--was not correct," brewer said. "the area was starved for facts, so you tended to get some very imaginative scenarios."
but even if the carbon dioxide mixes into the ocean, it could remain out of the atmosphere for centuries becuase deep ocean water takes hundreds of years to circulate back to the surface, say scientists at lawrence livermore national laboratory who used computers to simulate the process.
the technology is still a long way off. chemical engineers would have to find ways to capture large amounts of carbon dioxide--perhaps from power plant smokestacks--and a cost-effective way to convert the gas into liquid. still, brewer and others hope the technique will one day play at least a partial role in curbing warming by accelerating the natural process in which the ocean absorbs and stores carbon dioxide from the atmosphere.
"the capacity of the ocean is vast," brewer said. "if we're going to behave in an ethical way in the community of nations, we have to have a way to take care of energy wastes."
the department of energy, which partially funds brewer's work, is also backing research into the provocative idea of fertilizing the ocean with supertankers full of iron. phytoplankton--the tiny living specks that populate the ocean's waters--play a major role in regulating carbon dioxide by taking it out of the atmosphere and using it during photosynthesis. then, when the plankton die, they sink toward the bottom, taking their carbon with them.
because shortages of iron limit the growth of plankton in many parts of the ocean, adding the metal should lead to more plankton removing more carbon from the air. but open ocean experiments with iron fertilization conducted near antarctica in 1999 by scientists from the woods hole oceanographic institution found no proof that the excess carbon actually sink.
'shifting ecosystems on a grand scale'
beyond the question of whether the approach would work lie other risks. massive plankton blooms have the potential to alter the food web and kill fish. increasing plankton would also change the oxygen balance of the ocean, which, in turn, cold spur growth of bacteria that produce nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide.
the idea of changing how much plankton grows in the sea "really is shifting ecosystems on a grand scale," brewer said.
some geochemists, wiess included, are concerned about any plans to tamper with atmospheric and oceanic carbon cycles, which are fundamental to life but far from understood.
"i would be really hesitant to tinker with mother nature," wiess said.
david karl, a university of hawaii expert on marine organisms, will soon conduct an experiment on iron fertilization in a small section of ocean. fertilization techniques are far from perfect because of the mix of nutrients needed, he said.
"if you put in a tanker of iron, you'd have to put in 100 tankers of phosphorus," he said, adding that the next round of experiments could "help confirm or reject this as a management tool."
the energy department is also funding work to analyze the genetics--and perhaps re-engineer the workings--of microbes that take in and store carbon. though fueled by the flush of success in sequencing the human genome, the work remains speculative, scientists said.
a more immediate focus--and one taking center stage in kyoto negotiations--is whether carbon dioxide levels in the atmosphere should be reduced by managing land in lieu of drastically cutting emissions. in addition to planting forests and crops that take in more carbon dioxide, techniques could include changing tilling practices to reduce the amount of carbon dioxide escaping from soils. u.s. government officials like the idea because it would not harm the economy and because the united states has much open land to manage.
but the notion "seems to be increasingly politicized," said ian noble, a scientist at the cooperative research center for greenhouse accounting who favors such ideas as a way of reducing carbon dioxide growth in the short term. noble has been frustrated by a flood of reports in the european media dismissing such proposals as unworkable and harmful. these alternatives "can buy us time, and we need time," he said.
recent u.s. research, however, shows that forests and farmlands may not be as good at absorbing extra carbon dioxide as once hoped. researchers from duke university fumigated open forests with high levels of carbon dioxide to determine how much of the gas the wood and soils would absorb. the results showed that storage in soil was limited because microbes broke down the carbon dioxide. moreover, mature trees did not use up vast amounts of carbon dioxide because their growth was limited by other nutrients.
william schlesinger, a biogeochemist and dean of nicholas school of the environment and earth sciences at duke, who helped run the experiments, said the results have made him skeptical about the potential for creating so-called carbon sinks to trap excess carbon dioxide.
"we've got to get serious about cutting emissions," he said.
globally, there is only so much carbon the land and its plants can absorb. carbon sinks on land are estimated to become saturated within 30 to 100 years, said robert scholes, a terrestrial ecologist from south africa.
moreover, loading the land with carbon has its own downside. rich forests are potential targets for fire, which releases carbon right back into the atmosphere.
"we're building up to a more vulnerable system in the future," said bert bolin, a swedish scientist and former chair of the u.n.'s intergovernmental panel on climate change.
despite such concerns, carbon sinks are seen as crucial by many because they could help immediately reduce carbon in the atmosphere, thus buying some time for longer-term solutions. they are also politically important because they may draw unwilling participants, such as the u.s. and some developing countries, into attempts to limit greenhouse gases, said bob watson, chief scientist of the world bank and chariman of the u.n. climate-change panel.
the powerful u.s. farm lobby might push for such plans, which could be economically beneficial to farmers. poor countries in tropical regions such as africa could potentially earn money from richer nations by growing forests to offset carbon dioxide emissions, watson said.
but many others fear that developed nations will simply use land management as a way to shirk emission cuts.
"planting trees is a few drops in the bucket compared to the amount of fuel we're using," said weiss, the geochemist from scripps. "the 500-pound gorilla is the burning of fossil fuels."
note: i know this is an ~10 year old cite, but i doubt the numbers have significantly changed (probably the same, if not higher now); at that time, it was found that 25% of the world's entire automobile population was found in the state of california--alone. [don't know what the % was for the entire u.s.] that's a LOT of fossil fuel to be attributed to just one state in the u.s.--car culture, indeed.
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