- It’s True: Hot Water Really Can Freeze Faster Than Cold Water
- Climate Hackers Want to Write Their Own Rules
- 6 Ways We’re Already Geoengineering Earth
- Exclusive Excerpt: Hack the Planet
- Q&A: Geoengineering Is ‘A Bad Idea Whose Time Has Come’
- African Footprint Fossils Are Oldest Evidence of Upright Walk
Posted: 24 Mar 2010 09:47 AM PDT
Hot water really can freeze faster than cold water, a new study finds. Sometimes. Under extremely specific conditions. With carefully chosen samples of water.
The Mpemba effect is named for a Tanzanian schoolboy, Erasto B. Mpemba, who noticed while making ice cream with his classmates that warm milk froze sooner than chilled milk. Mpemba and physicist Denis Osborne published a report of the phenomenon in Physics Education in 1969. Mpemba joined a distinguished group of people who had also noticed the effect: Aristotle, Francis Bacon and René Descartes had all made the same claim.
On the surface, the notion seems to defy reason. A container of hot water should take longer to turn into ice than a container of cold water, because the cold water has a head start in the race to zero degrees Celsius.
But under scientific scrutiny, the issue becomes murky. The new study doesn't explain the phenomenon, but it does identify special conditions under which the Mpemba effect can be seen, if it truly exists.
"All in all, the work is a nice beginning, but not systematic enough to do more than confirm it can happen," comments water expert David Auerbach, whose own experiments also suggest that the effect does occur.
Papers published over the last decade, including several by Auerbach, who performed his research while at the Max Planck Institute for Flow Research in Göttingen, Germany, have documented instances of hot water freezing faster than cold, but not reproducibly, says study author James Brownridge of State University of New York at Binghamton. "No one has been able to get reproducible results on command."
That's what Brownridge has done. One of his experiments, presented online, repeatedly froze a sample of hot water faster than a similar sample of cool water.
Note the word similar. In order for the experiment to work, the cool water had to be distilled, and the hot water had to come from the tap.
In the experiment, about two teaspoons of each sample were held in a copper device that completely surrounded the water, preventing evaporation and setting reasonably even temperatures. Freezing was official when sensors picked up an electrical signal created by ice formation.
Brownridge heated the tap water to about 100° C, while the distilled water was cooled to 25° C or lower. When both samples were put into the freezer, the hot water froze before the cold water. Brownridge then thawed the samples and repeated the experiment 27 times. Each time, the hot tap water froze first.
The experiment worked because the two types of water have different freezing points, Brownridge says. Differences in the shape, location and composition of impurities can all cause water's freezing temperature — which in many cases is below zero degrees C — to vary widely. With a higher freezing point, the tap water had an edge that outweighed the distilled water's lower temperature.
Because the experiment didn't compare two identical samples of water, the mystery of the Mpemba effect is not really solved. "I'm not arrogant enough to say I've solved this," Brownridge says. But he has set some guidelines about when the effect can be seen.
Physical chemist Christoph Salzmann of the University of Durham in England says he's not convinced the Mpemba effect really exists, because there are innumerable things that influence the timing of freezing, making it impossible to completely control.
Predicting how long it will take for a water sample to crystallize "is a bit like trying to predict when the next earthquake or crash of the stock market will happen," he says. "I would not want to say that the Mpemba effect does not exist. But I have still not been convinced of its existence."
Image: Kenn Wilson/flickr
Posted: 23 Mar 2010 05:00 PM PDT
This week, 200 scientists will gather in an attempt to determine how research into the possibilities of geoengineering the planet to combat climate change should proceed.
They say it's necessary because of the riskiness and scale of the experiments that could be undertaken — and the moral implications of their work to intentionally alter the Earth's climate.
The group is meeting at the Asilomar resort in California, a dreamy enclave a few hours south of San Francisco. The gathering intentionally harkens back to the February 1975 meeting there of molecular biologists hashing out rules to govern what was then the hot-button scientific issue of the day: recombinant DNA and the possibility of biohazards.
The 1975 process wasn't perfect, but after a fraught and meandering few days, the scientists released a joint statement that placed some restrictions and conditions on research, particularly with pathogens. That meeting is now held up as a model for how researchers can successfully assume the mantle of self-regulation.
"And perhaps that was the final, foggy significance of Asilomar: a promise that the scientists who deal with the most fundamental of life stuff will not sequester themselves beneath Chicago stadiums or within blockhouses in the New Mexico desert — that their work, at least as significant as the most subtle of sub-nuclear manipulations, will be done with care and public scrutiny," wrote Michael Rogers in a June 19, 1975 Rolling Stone article.
Organized by the Climate Response Fund, a new group created to support geoengineering, this week's conference is self-consciously recalling its famous Asilomar predecessor: All the participants in the new conference were sent Rogers' article.
A conference brochure summed up the popular attitude toward its predecessor, praising it "as a landmark effort in self-regulation by the scientific community" and attributing the lack of "dangerous releases of organisms modified with recombinant DNA" to the "effectiveness of the ultimate guidelines and procedures." It includes a black-and-white photograph of 1975 scientists meeting in the resort's hoary chapel (above).
But in important ways the the two Asilomars are different. The Climate Response Fund was founded by Margaret Leinen, who although a respected scientist, had a commercial interest in a company doing geoengineering. The original Asilomar had a more official provenance: It was organized by the National Academy of Sciences with $100,000 from the National Institutes of Health and the National Science Foundation.
But even if the two conferences were identical, the real history of the '75 Asilomar conference highlights the problems of scientific self-governance as much as the solutions it offers. It was messier than most would probably like to recall.
Crucially, the 1975 Asilomar meeting sidestepped the question of how recombinant DNA research should be done and who it should benefit, in favor of the more technical question of how it could be done more safely.
"The recombinant DNA issue was defined as a technical problem to be solved by technical means, a technical fix," wrote MIT historian of science Charles Wiener in a 2001 retrospective. "Larger ethical issues regarding the purposes of the research; long-term goals, including human genetic intervention; and possible abuses of the research were excluded."
This year's version of Asilomar could draw even more attention to the fundamental tension of scientific self-regulation of risk- and value-laden experiments. While many of the field's top scientists are attending the meeting, it has drawn criticism from high-level scientists with an interest in geoengineering like Stanford's Ken Caldeira and the University of Calgary's David Keith.
"My only concern about this meeting is that the convening organization, [Climate Response Fund] is nontransparent and appears to be closely tied to Climos which was conceived to do ocean fertilization for profit," Keith wrote. "While I am happy to see profit-driven startups drive innovation, I think tying ocean fertilization to carbon credits was a sterling example of how not to govern climate engineering, and I am therefore concerned to see a closely linked organization at the center of a meeting on governance. A meeting on governance ought to start by having transparent and disinterested governance."
Despite Keith's strongly worded statement about the conference, he has decided to attend to, as he put it, "speak out." Caldeira declined his invitation, telling Wired.com that he preferred governance meetings held by "established professional societies and non-profits without a stake in the outcomes."
The 1975 Asilomar conference did go through more established routes and even with that pedigree, the molecular biologists struggled to come up with a decision-making strategy that could address the concerns of the public.
"The motive from the start was to reduce potential hazards and to proceed with the research, avoiding public interference by demonstrating that scientists on their own could protect laboratory workers, the public and the environment," MIT's Wiener continued. "Of course, this action contained a contradiction: They were dealing with a public health issue and simultaneously attempting to keep the public out of it."
Certainly, there's a logic to letting experts in a scientific field decide about the field's future. The presumption is that those closest to the science know its possibilities — both good and bad — best. Yet, that assumes that the science is guiding the proceedings.
Rolling Stone's Rogers recorded a remarkable amount of confusion and the suggestion that the conference's organizers had structured the rules to protect their own lines of research, while limiting other people's work. In a March 22, 1975 article, Science News' Janet Weinberg described the scientists' collective response to draft rules as "a barrage of unyielding, self-indulgent, and conflicting attitudes."
This historical reality led Tufts University bioethicist Sheldon Krimsky to write that the modest regulations that emerged from Asilomar were not based on some systematic definition of risk, in the 1982 book, Genetic Alchemy: The Social History of the Recombinant DNA Controversy. Rather, they represented a much more human solution, a "negotiated settlement among scientists incorporating some science and considerable conjecture and intuition."
While most scientists believe that the Asilomar meeting was a qualified success, some do not. The most outspoken, DNA co-discoverer, James Watson, reportedly blurted out during panel on risk, "These people have made up guidelines that don't apply to their own experiments." Watson argues the conference led to the creation of "totally capricious and totally unnecessary" guidelines and actually made the public more afraid of biotechnology. In 1978, Watson railed against Asilomar and similar meetings, saying they were "a real theater of the absurd in which the only professionals were a bizarre collection of kooks, sad incompetents, and down-right shits."
It's obvious but worth noting that Watson was concerned that science was, and would be, too limited. In fact, he had experiments that he had to put off for two years due to the regulations. But social scientists have generally drawn the opposite conclusion about Asilomar's power to limit science.
Susan Wright, a historian of science at the University of Michigan, has called the bargain supposedly struck at Asilomar — some research restrictions in exchange for scientific self-governance — a myth on both sides of the deal.
"It is a myth that most scientists working under competitive pressures can address the implications of their own work with dispassion and establish appropriately stringent controls — any more than an unregulated Bill Gates can give competing browsers equal access to the world wide web," she wrote. "Sure enough, some five years later, the controls proposed at Asilomar and developed by the National Institutes of Health were dismantled without anything like adequate knowledge of the hazards."
Further, she says, "it is equally a myth that scientists in this field are self-governing." Instead, their research agendas are shaped by utilitarian interests of government or corporate sponsors. Even at that early stage, before the biotech boom of later years, molecular biologists were never doing pure science.
Even researchers who consider the 1975 Asilomar conference a success, who convened on its 25th anniversary realize that the its process is no longer feasible.
"While there is general agreement that the 1975 Asilomar meeting made a large contribution to the resolution of a major scientific policy issue, it was clearly the consensus at the 2000 meeting that perceptions of science and of scientists have changed so drastically over the last quarter century that it is virtually inconceivable that a similar format could be successful today," wrote the editors of Perspectives in Biology in a special issue in 2001.
The Asilomar conference this week will have to deal head-on with these dilemmas. Odds are, no matter what happens, any statement that comes out of the meeting will be incomplete, unfinished and provisional. It should also incorporate and remain open to input from critics of geoengineering.
Perhaps, the messy negotiations of parties guided by science and their own interests will push the discussion to the sensitive middle ground that the 1975 conference found, making no one totally happy, but recognizing the potential — good and bad — of a radical new field of scientific inquiry.
Images: National Academy of Sciences.
Posted: 23 Mar 2010 05:00 PM PDT
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Scientists and policymakers are meeting this week to discuss whether geoengineering to fight climate change can be safe in the future, but make no mistake about it: We're already geoengineering Earth on a massive scale.
From diverting a third of Earth's available fresh water to planting and grazing two-fifths of its land surface, humankind has fiddled with the knobs of the Holocene, that 10,000-year period of climate stability that birthed civilization.
The consequences of our interventions into Earth's geophysical processes are yet to be determined, but scientists say they're so fundamental that the Holocene no longer exists. We now live in the Anthropocene, a geological age of mankind's making.
"Homo sapiens has emerged as a force of nature rivaling climatic and geologic forces," wrote Earth scientists Erle Ellis and Navin Ramankutty in a 2008 Frontiers in Ecology paper, which featured their redrawn map of the human-influenced world. "Human forces may now outweigh these across most of Earth's land surface today."
Draining the Rivers
Posted: 23 Mar 2010 05:00 PM PDT
The battle lines on geoengineering have begun to take shape. On one side are modern-day romantics, who consider geoengineering an a priori violation of humans' role as planetary citizens to let nature be natural and take a humble place within it. Better to solve the climate problem by reducing our impact on the planet, they say. Prominent among their antecedents is American forestry ecologist and writer Aldo Leopold, who asserted in A Sand County Almanac in 1949 that environmental problems demanded that man change his role from "conqueror of the land community to plain member and citizen of it."
"A wilderness is where the flow of wildness is essentially uninterrupted by technology; without wilderness, the world's a cage," wrote David Brower, the former executive director of the Sierra Club. Technology and development, he lamented, had rid most of the world of this essential quality.
Extending this common trope of American environmentalism to the question of climate engineering would be writer and climate activist Bill McKibben, who views geoengineering as the "junkie logic" of a culture addicted to technological solutions. He has urged humanity "to truly and viscerally think of ourselves as just one species among many."
And then there are the rationalists, who believe that to minimize suffering, it just may be more technological hubris that our species needs. In The Whole Earth Catalog, first published in 1968, Brand wrote of humanity's responsibility as Earth's gardeners and caretakers, "We are as gods, and might as well get good at it." Recently he updated his thinking. "Those were innocent times. New situation, new motto: ' We are as gods and have to get good at it.'"
He views geoengineering as part of an "eco-pragmatist" approach. "Whether it's called managing the Commons, natural infrastructure maintenance, tending the wild, niche construction, ecosystem engineering, mega gardening, or intentional Gaia, humanity is now stuck with the planet's stewardship role," he wrote in 2009.
Deciding what role geoengineering should play as the climate crisis unfolds in the twenty-first century will take balancing both Enlightenment perspectives. And yet we may not have a choice between embracing the God role with climate models and artificial volcanoes or shunning it to take our place among the rest of the species. Events, and catastrophic ones, may dictate our decisions.
Perhaps climate stewardship simply won't work, and tinkering with the atmosphere won't be available. Or it will — and we'll kill one another over the thermostat. Now we contemplate wielding global powers previously imagined only in science fiction. Maybe the biggest question we'll face may be how changing the planet will change ourselves….
The idea of deliberately manipulating the weather or the climate is an especially powerful notion. We equate weather with mood because our bodies are so affected by temperature and moisture and light. Storms trouble our minds as well as threaten our coasts. Climate is our experience of the weather over time and space, the way weather shapes our summers or our neighborhoods. To control climate — especially now, at a time when it seems so unpredictable — promises stability and peace for us and our children.
The seductive idea of weather and climate control has been a constant trope in the human imagination. The sorcerer Prospero in Shakespeare's Tempest conjures bad weather to drive his enemy's boat ashore. In the 1985 film Brewster's Millions, Montgomery Brewster, played by Richard Pryor, invests in a scheme to haul icebergs to the Middle East to provide water. Advanced societies control the weather as a matter of course in the worlds of Star Trek and Dune. When it comes to our air and rain, our control fantasies are strong.
One finds in the rhetoric about geoengineering — especially among fervent advocates of the idea — the misleading notion that one ought to find comfort in the notion of hacking the planet. Opponents of geoengineering "would rather let nature translate human actions . . . into the ultimate effects on climate," wrote economist Alan Carlin. But he believes "it would be better for humans to determine the desired climato - logical outcomes (such as lower average temperatures) directly and relatively precisely rather than letting nature, which has no incentive to help humans, sort out the net effects." Nature is wild, in other words, and scientists are rational — they'll tame it. That way we can choose what kind of planet we want, instead of leaving it up to chance. There's also the immediate appeal of the notion that through ingenuity we might escape undesirable limits. Or the consequences of our actions. Or the blame.
Of course we can't tame this planet. Not in the next few decades, when we might have to. We may have to try, but attempting to dictate how much solar energy strikes the planet is a dangerous endeavor, perhaps involving just as much chance as our current course. Being forced to geoengineer would be a dismal fate. It would be the solution we deserve, as a friend put it. One finds one's ten-year-old son smoking a cigarette? Put him in the closet and make him smoke the whole pack.
Succumbing to the illusion of control would mean replacing one burden — navigating the dangers of today's climate crisis, and overhauling the world's energy system — with the much more risky burden of revolutionizing our relationship with the sky itself. The illusion of control — "Everthing's okay, the scientists have fixed the problem" — could engender apathy at a time when we desperately need to stop pouring carbon dioxide into the sky. It could drive nations apart during a planetary emergency, when they most require unity. It might work in unexpected ways or not at all.
Control may be comforting, but it's also an illusory burden we should not fall into the trap of seeking. We have no choice but to understand it. Maybe we'll succeed. But hacking our planet is not yet our fate. We might be able to avoid it. Perhaps David Brower, a modern-day romantic if there ever was one, was right: technology does make the world into a cage. Maybe geoengineering makes it more like a terrarium, an enclosed, controlled garden. Even if geoengineering helps us one day stave off the worst of the climate crisis, we'll still be inside its walls.
Images: 1) Julie Turkewitz. 2) Biosphere 2./ scottfidd/flickr.
Posted: 23 Mar 2010 05:00 PM PDT
While humans have unintentionally been altering Earth's climate for centuries, some scientists have begun to study how to intentionally hack the globe to cool the overheated planet.
Eli Kintisch's new book, Hack the Planet provides a thorough and nuanced portrait of the development of geoengineering. Through long acquaintance with the field's biggest names, Kintisch, a staff writer for Science, paints a deep sociological portrait of a radical new scientific discipline bursting messily into the world.
He reminds us that even though the techniques may be wild and global, many of the people dreaming them up are regular scientists trying to deal rationally with a carbon problem that they don't see society solving. Faced with a warming world, they are torn between watching nature die or trying to surgically kill it themselves.
Wired.com: What are some of the basic geoengineering options being discussed?
Eli Kintisch: The main geoengineering techniques fall into two basic categories: One, the ways to block sunlight at different points in the atmosphere and earth system to lower the temperature rapidly in that way, and the other is enhancing the planet's ability to take up carbon dioxide through a variety of techniques. So, sun-blocking and carbon-sucking are the two main ways.
With sun-blocking, what you are essentially doing is brightening the planet, increasing the earth's albedo. That can change the amount of total radiation that the planet experiences. Scientists have proposed ways of intercepting solar radiation at every single point from the surface of the earth by whitening roofs or brightening the ocean's surface itself with tiny bubbles, to brightening low-lying and high clouds, to one of the most radical and discussed geoengineering techniques: adding particles called aerosols to the stratosphere. That technique has many names, but I like to call it the Pinatubo option, because it was influenced by the rapid cooling that follows volcanic eruptions.
The Pinatubo option involves spraying some kind of particles (usually people talk about sulfur) into the upper atmosphere to form a kind of haze that blocks a small percentage of the sun's rays before they can enter the lower atmosphere.
The carbon methods involve generally enhancing natural systems to take in more carbon, perhaps genetically modifying plants so they have more carbonaceous cells or growing large blooms of algae in the ocean by using some sort of key nutrient that can catalyze and fertilize their growth. The main way has been to use iron. You could also build machines to suck in the carbon dioxide.
Wired.com: You pinpoint one moment as really touching off the latest interest in geoengineering: a paper by Paul Crutzen. Why was that paper so influential?
Kintisch: Scientists had considered mimicking the cooling effect that volcanic aerosols have on the planet for decades before Crutzen's paper. The scientist who first published on it was the Soviet scientist Budyko. But Crutzen came at a time where many scientists felt that the climate crisis was accelerating and he had the stature of a Nobel Prize. As an atmospheric chemist, he certainly had knowledge in this particular field.
And while he does have a reputation as a bit of a maverick, Crutzen's paper was assiduously spelled out and he sent it to all of the top minds in the field before publishing it. That made it hard to argue with his essential conclusion, which is that we better at least study the method. It was difficult for anyone to disagree with. The furthest people could go was arguing that the paper shouldn't be published. It was controversial and required intervention by the president of the National Academy of Science, Ralph Cicerone, an atmospheric chemist himself and friend of Crutzen.
Wired.com: Early in your book, you split the people working on geoengineering into two basic camps: the red team and the blue team. Who are these teams and how are they different?
Kintisch: First, I don't think anyone really wants to do geoengineering right now. Maybe a handful of people think we are at that stage or think it would be a good idea to "take control." But the [blue team] scientists who are starting to spend more of their time studying geoengineering are generally engineering types, the kinds of scientists who like to think up new solutions and create new ideas and synthesize existing ones. The red team scientists have more of the temperament of skeptics. They are better at shooting holes in proposals and identifying problems. For any field, you usually have these two types.
The blue team includes most famously Edward Teller [nuclear scientist and former head of Lawrence Livermore National Laboratory], who passed away in 2003, and his acolyte Lowell Wood. They are two of the blue team when it comes to the Pinatubo option. Then, when it comes to cloud-brightening, you have a British scientist named John Latham, who for most of his life has studied weather and came up with a way to brighten clouds. And when it comes to iron fertilization, which is growing algae blooms, there are a variety of scientists but most notably John Martin.
The red team includes scientists who have focused on the ways that these solutions could be deleterious, or on early technical problems with them. For the stratospheric aerosols, there is an expert on volcanoes, Alan Robock at Rutgers, who has focused on the problems with the Pinatubo option. For iron fertilization, there is an ecologist, Penny Chisholm at MIT, who is mostly focused on a variety of ecological and environmental issues related to growing these giant algae blooms.
Wired.com: One fascinating connection you draw is between scientists developing the atomic bomb and scientists working on geoengineering. "You hope to God this is never used but if you have to use it, you better know how it behaves," David Battisti tells you. That argument runs throughout post-war science. Does anyone have a better answer than the atomic scientists did?
Kintisch: At this point, a lot of scientists feel the cat is out of the bag. If anything, a desperate politician 30 years form now may suddenly decide, "I need to cool the planet." And if we don't study it, scientists won't have any way to warn this leader of what the consequences will be. From that perspective there is a Pandora's box that has been opened.
Geoengineering is a bad idea whose time has come. It is something that you have to study and hope to never use. [For the atomic scientists], the other side has nuclear weapons and they are pointed at you, so you have no choice but to develop a deterrent. In this case, the nuclear weapons are the unknown chance that the planet's sensitivity to CO2 is very high and will respond to some of these worst-case tipping points.
Scientist feel they have no choice but to develop this response that viscerally is almost sickening to many scientists, especially someone like David Battisti, who thinks a lot about the internal dynamics of the climate system and understands how hard it is to understand how the parts fit together and then predict its behavior.
Wired.com: We talk a lot about the "tails" of climate-change risk, the big, seemingly low-probability stuff that could have a major impact. Do we know what the tails of geoengineering schemes, particularly the Pinatubo option, are? Is there some slight chance that something really bad could happen?
Kintisch: For the most part, scientists are trying to focus their efforts on geoengineering ideas that have some natural analogue. The Pinatubo option mimics volcanoes. Cloud-brightening happens as a result of salt particles and dust.
But, we don't really know that much at all about any of these wild concepts. So, what scientists say is that the best way to make a decision is to compare not doing geoengineering and experiencing the worst-case scenarios of global warming with doing geoengineering and experiencing the tails or worst-case scenarios of geoengineering.
Often a mistake people make in talking about this, is that they consider that geoengineering schemes would work perfectly without weighing that there would be these unintended consequences.
Wired.com: Do you think it will be possible to design experiments that can address the risks and uncertainties of geoengineering?
Kintisch: I think in all areas of science involving risk, it's probably fair to say that there is no such thing as the perfect experiment that gives you the information you want and involves the least amount of risk. The best example is drug trials. People even die after a drug has been studied. In geoengineering, this gets down to how much information we will need to act in the future. We might be able with the Pinatubo option to understand more about the consequences on ozone. But we may not have thought to ask about other effects, like the impacts of diffuse light on various ecosystems. The larger you go [with experiments], the better the chance that you're going to discover the unknown unknowns. But the larger you go, the greater the risk that the studies themselves will have a deleterious effect.
Wired.com: One of your sources asks you, "If, say, a Huckabee administration suddenly woke up and started geoengineering the planet, what could anybody else do about it?" This seems like a real question. What would anyone else do about it?
Kintisch: I'm not an expert on international relations or nuclear brinksmanship, but I do think that we have no idea. One thing that makes that question hard to answer is that we don't know how severe the climate crisis would have to be before countries would consider unilateral geoengineering. Would there be food conflicts? Would there be problems with immigration? What other factors would be happening? Would it be a developing country with nuclear weapons or a coalition of nations?
This gets to the reason that scientists are meeting now in Asilomar. The worst- case scenario is, with any new risk, you don't want its existence or its use in the future to cause conflict in and of itself. One way to do that is to set up international norms and agreements that countries cooperate, and the technology itself won't become a flashpoint for conflict like what happened with nuclear weapons after WWII.
But the challenge for setting up rules for geoengineering is that scientists very rightly fear that if rules are set up right now, we might restrict research that might tell us things we need to know about geoengineering.
You don't want a free-for-all with everyone going out and trying geoengineering at a large scale out of fear or strategic reasons. But you have to do some studies to understand what those rules should be. And the scientists here in Asilomar are trying, at an early stage, to lay out voluntary guidelines to square that circle, and do some studies in the environment that could give us some early clues about the risk of geoengineering.
Wired.com: It seems like the toughest issue is having some sort of global governance structure in place. But if we got that in place, wouldn't we be most of the way toward a meaningful way to keep carbon in the ground?
Kintisch: That's an interesting point. If we can't get our act together to reduce by a relatively modest percent, this very dangerous trace gas that we're spitting into the atmosphere, it does suggest that we're going to have a lot of trouble regulating geoengineering.
One problem with geoengineering research that scientist Ken Caldeira has pointed out to me is that there are a lot of private companies who are involved in this research, who are out to do research but also to create a business around selling carbon credits. Is this a field that should be dominated by private enterprises?
I titled the chapter on the history of climate and weather modification as a pursuit of levers. Because what I think geoengineering comes down to is looking for levers, making small changes that have big effects in the climate system. And that's usually the goal of a company, they look for ways to profit off a small investment and yield big returns.
We're looking for good investments for our geoengineering buck, so it doesn't surprise that you'd have [private companies] Climos and Planktos interested in the very lucrative leverage involved in iron fertilization. And Nathan Myhrvold, inventor and close confidante of Bill Gates, interested in the stratospheric aerosols.
Wired.com: But is this an area where the work should be done just with national sponsorship?
Kintisch: Unlike most branches of Earth sciences, geoengineering is this kind of radically multidisciplinary idea. You take a supposed understanding of a basic system and develop an engineering method of altering or radically changing it. Generally, when it comes to developing real-world products, scientists come up with the kernel of the idea and companies have proven to be the best at turning the kernel into a working technology. In a way, I can see the allure of letting companies develop geoengineering ideas because they are set up to try different things and the allure of profits can drive new ideas.
That said, it is a really worrisome proposition that for-profit companies would be entrusted in developing techniques that might be deployed and have such far-reaching environmental or ecological consequences. That's why openness and transparency and scientific integrity is so important in this field.
Wired.com: You're heading to the Asilomar conference today on geoengineering. Do you see a scientist-led effort to regulate themselves internally as the best way of proceeding with small-scale research? Are they capable of that?
Kintisch: I think in other areas of science, researchers have shown that they are able to regulate themselves, at least initially. There is usually this tension between the scientists wanting to regulate themselves because they want a free hand in exploring a bunch of ideas, but then at some point having the officials come in.
It's such an early stage with geoengineering. Many of the people involved with it don't have experience working with dangerous things. They are Earth scientists or energy experts. They don't have the institutional experience that scientists in molecular biology have developed over the years.
And when it comes to molecular biology, there still are struggles between the community of scientists who study sensitive pathogens and governments. That community got started in regulating itself here in 1975.
It may sound like a lame answer, but there will be a continuous push and pull on geoengineering.
Wired.com: The biggest argument against geoengineering research raised by critics is that it causes delays in going after carbon emissions directly, and quite possibly will kneecap those efforts by providing political cover for big emitters. Do you think that's a strong enough argument to pull geoengineering off the table?
Kintisch: I don't think so. All the time we deal with moral hazard. We deal with it when it comes to insurance or people wearing seatbelts. As a society, we should be able to deal with the moral hazard of people understanding that geoengieering is a dangerous concept that has to be studied and should be kept as an absolute worst-case scenario, but that requires vigorous and public debate. It probably requires a more scientifically literate society than we have. When someone says a quick fix is available and you don't know much about geoengineering, you might easily be persuaded.
So, I think moral hazard is among the dangers of intervening on a larger scale with the planet, but like any of them, it shouldn't discount an idea that we have little choice but to look at.
Image: Kathleen Smith/LLNL
Posted: 23 Mar 2010 10:51 AM PDT
Despite a penchant for hanging out in trees, human ancestors living 3.6 million years ago in what's now Tanzania extended their legs to stride much like people today do, a new study finds. If so, walking may have evolved in leaps and bounds, rather than gradually, among ancient hominids.
The discovery comes from the famed trackway site in Laetoli, Tanzania, where more than 30 years ago researchers discovered footprint trails from two, and possibly three, human ancestors who had walked across a wet field of volcanic ash. The new analysis shows that the Laetoli hominids made equally deep heel and toe impressions while walking across a soft surface, say anthropologist David Raichlen of the University of Arizona in Tucson and his colleagues.
That pattern is a cardinal sign of a humanlike gait, and suggests that an energetically efficient, extended-leg stride appeared surprisingly early in hominid evolution, Raichlen's team proposes in a paper published online March 22 in PLoS ONE. Until now, many researchers suspected that such a gait did not appear at least until the appearance of early Homo species around 2.5 million years ago.
"By the time hominids walked through the ash at Laetoli, they walked more like us than like apes," Raichlen says.
Many anthropologists attribute the Laetoli prints to Australopithecus afarensis, the species that includes the partial skeleton dubbed Lucy.
Some researchers previously argued that the Laetoli footprints resulted from a humanlike gait. Others have seen signs of a bent-knee, bent-hip stride characteristic of modern chimpanzees. The new investigation challenges that view.
"Raichlen's data are persuasive but admittedly limited in focus," remarks anthropologist William Jungers of Stony Brook University Medical Center in New York. Lucy's species differed from modern humans in ways that might have created gait disparities, in his view. Still, heel and toe depths at Laetoli provide a glimpse of efficient walking "long before the emergence of our own genus, Homo," Jungers says.
Raichlen's group is the first to analyze the Laetoli footprints from a biomechanical perspective. Eight adult volunteers walked twice across a lightly moistened sand walkway meant to reproduce the conditions in which the Laetoli prints formed. They then walked twice across the same sand surface while assuming a crouched stance. Special motion tracking and scanning equipment calculated the degree to which each person's hips and knees bent during all trials and generated three-dimensional models of participants' footprints.
People walking with an erect gait produced footprints with nearly equal heel and toe depths, the team found. In contrast, a crouched stride yielded markedly deeper toe impressions than heel impressions, reflecting faster weight transfer over the length of the foot.
To Raichlen's surprise, previous calculations of Laetoli footprint depths closely matched the even heel and toe depths left by people walking in their usual fashion.
A. afarensis fossils display an inwardly curved lower back, pronounced foot arches and other traits consistent with Raichlen's evidence for a humanlike gait at Laetoli, comments anthropologist Carol Ward of the University of Missouri in Columbia. "Any energy inefficiencies in walking relative to later Homo would have come from a small body size and wide body breadth, nothing more," she says.
No one knows precisely how hominids before Lucy's time walked. Ardipithecus ramidus, known primarily from a 4.4-million-year-old partial skeleton (SN: 1/16/10, p. 22) did not walk like people today, but the nature of its gait is unclear, he says.
"I doubt that the case is closed on debate over what gait was like in australopithecines, but this new study has made important strides in that direction," says anthropologist Brian Richmond of George Washington University in Washington, D.C.
Image: A) modern human footprint, upright gait. B) modern human footprint, bent-knee, bent-hip gait. C) Laetoli footprint./David Raichlen/PLoS.
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