Is there any way Ayesha could condense these stories with links, and post once a week? I am really getting inundated by this constant stream of emails. If everyone else is happy with the large number of emails posted by Ayesha, that's obviously fine, but I may have to get off of this listserve myself.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Jessica Gurevitch Distinguished Professor and Co-Chair Department of Ecology and Evolution Stony Brook University Stony Brook, NY 11794-5245 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ On Wed, Dec 21, 2022 at 4:51 AM ayesha iqbal <[email protected]> wrote: > http://www.asee-prism.org/dimmer-switch/ > *November 2022 *By Mark Matthews > > Aerospace engineer James T. Early built a 30-year career at the Lawrence > Livermore National Laboratory working out big ideas. Among them: the use of > pulsed lasers to knock space debris out of orbit, and a giant > telescope—powerful enough to detect planets in distant solar systems—with > lenses that roll up to fit inside a rocket and then spread out when > launched in space. Trained at MIT, Caltech, and Stanford, Early drew > inspiration from the science fiction of Isaac Asimov and Arthur C. Clarke. > When his wife wanted to try her hand at the genre, he outlined a debut > plot: terraforming Venus. An immense sun-blocking shield, he theorized, > could cool the planet over time and turn its scorching, desiccated surface > into a human habitat. > > Early wondered if a scaled-down sunshield could solve the real-life > problem of a warming Earth caused by carbon-spewing power plants and > vehicle exhaust. In three terse pages published in the *Journal of the > British Interplanetary Society* in 1989, he spelled out a “conceptually > simple method” for offsetting the heat-trapping greenhouse effect and > cutting global temperatures by 2 degrees Celsius (3.6°F). A glass shield > could be fabricated on the moon out of lunar soil and dispatched, using an > electromagnetic accelerator, to the first Lagrange point (L1), a million > miles from Earth, where the gravitational pull of the Earth and sun cancel > each other out. He hazarded a price tag of $1 trillion to $10 > trillion—“enormous,” yes, but perhaps much lower than the economic impact > of the greenhouse effect. > > Roger Angel, an esteemed astronomer at the University of Arizona, built on > Early’s idea in 2006. He conceived a giant space cloud at L1 comprising > trillions of thin reflective satellites, each a meter wide and weighing 1 > gram. These little “flyers” would be kept aligned with the sun by solar > sails, which are powered by photons of sunlight bouncing off a mirrored > surface. Manufactured on Earth, the satellites would be sent aloft to L1 in > stacks of 800,000 using electromagnetic acceleration and ion propulsion. > They would form a cloud some 60,000 miles long and 2,000 miles across, > weighing 20 million tons. Angel’s detailed six-page description in the > *Proceedings > of the National Academy of Sciences* estimated a cost of “a few trillion > dollars.” The idea, he wrote, might be desirable if “dangerous changes in > global climate were inevitable.” > > Early and Angel were each ahead of their time in combining futuristic > space technology with the science of preventing catastrophic climate > change. But their vision of a vast sunshield looks a bit more realistic > now, amid such advances as a fledgling space tourism industry, reusable > rockets curbing the cost of space launches, and growing interest in > space-based manufacturing and moon and asteroid mining. Meanwhile, as the > effects of climate change become alarmingly clear and warnings by the > Intergovernmental Panel on Climate Change grow more precise and ominous, a > growing number of scientists, engineers, graduate students, and members of > Congress are looking to geoengineering as a possible when-all-else-fails > technical fix for an overheating planet. > > Enter Space Bubbles, a 2022 variation on the sunshield idea from a team of > MIT engineers. Led by Carlo Ratti, director of the university’s Senseable > City Lab, the group envisions giant space platforms—“rafts”—composed of > stuck-together inflatable spheres of thin-film silicon or another molten > material, positioned slightly closer to the sun than L1. The spheres would > be manufactured using “space-based fabrication methods” not clearly > defined. Like the Early and Angel concepts, the rafts would block 1.8 > percent of the sun’s rays—an amount sufficient to prevent dangerous > warming. The cooling could begin by the end of this century, “when the most > severe consequences of climate change are currently predicted,” the team > says. As to price, “Our initial estimations suggest that the Space Bubble > Raft will have lower mass-density than Roger Angel’s proposal and might > thus be more cost-efficient,” Ratti tells *Prism.* > > Space Bubbles brings a disruptive, Elon Musk-style audacity to > geoengineering (also known as climate intervention) and to the small but > prolific community of scientists and engineers who have spent years or even > decades studying other climate-cooling methods that would operate much > closer to the Earth’s surface. Members of this community would prefer that > such methods never be necessary; almost in unison, they insist that > geoengineering would not be a substitute for slashing greenhouse gas > emissions. But they work with the intensity of people who view climate > intervention as an essential hedge against disaster and want to ensure that > its feasibility and risks are understood. As Douglas MacMartin, a Cornell > University aerospace engineer and geoengineering researcher, explains, the > goal is to “provide enough knowledge that the world . . . can make informed > decisions about this” versus “knee-jerk” reactions such as “‘Oh, things are > desperate. We need to go try something,’” or “‘Oh, that sounds like a bad > idea. We shouldn’t do it.’” > Policy Matters > > Increasingly, people in Washington agree. Citing “potentially catastrophic > consequences” of global warming, a panel of the National Academies of > Science, Engineering, and Medicine (NASEM) last year urged the federal > government to establish, in coordination with other countries, a modest > transdisciplinary research program on solar geoengineering (SG) that > “attempts to moderate warming by increasing the amount of sunlight that the > atmosphere reflects back to space or by reducing the trapping of outgoing > thermal radiation.” The NASEM panel, which included MacMartin, said > knowledge gained from the recommended research “will be critical for > informing climate change response strategies, and evidence either in favor > or disfavor of SG deployment could have profound value.” > > As NASEM issued its findings, Congress directed the White House Office of > Science and Technology Policy (OSTP) to develop a working group among the > non-defense federal science agencies to manage near-term climate hazard > risk and coordinate climate intervention research. The working group > “should also establish a research governance framework to provide guidance > on transparency, engagement, and risk management for publicly funded work > in solar geoengineering research,” appropriators said. > > A congressional mandate, participation of multiple federal agencies, and > direction from the White House promise to elevate geoengineering from a > controversial niche science to a mainstream research field relevant to > policymakers. David Keith, a Harvard applied physicist and an influential > proponent of geoengineering research, has been calling publicly for such a > step since at least 2010. (See *Prism’s* October 2013 Up Close profile > <https://www.asee-prism.org/up-close-oct-1/> and February 2019 cover > story.) <https://www.asee-prism.org/polar-prospects/> Testifying that > year before the House Science and Technology Committee, he likened > geoengineering to chemotherapy as an undesirable but possibly necessary > emergency measure. “We must hope for the best while laying plans to > navigate the worst,” Keith told the lawmakers. > > Planning for “the worst” is shaping up as prudent strategy. The world has > failed to keep pace with the cuts in greenhouse gas emissions required by > the 2015 Paris agreement, which aims to cap the global temperature this > century at well below 2 degrees Celsius above preindustrial levels and > calls for progress toward a limit of 1.5 degrees Celsius (about 2.7° > Fahrenheit). The $369 billion in US climate and clean energy programs > contained in the recently enacted Inflation Reduction Act falls short in > fulfilling the country’s pledge to slash emissions. Some provisions do win > applause from experts, however. For instance, the new law’s measures to > control methane, a super-potent greenhouse gas, are “very encouraging,” > says Yangyang Xu, an assistant professor of atmospheric sciences at Texas > A&M University. He adds: “The direct and heavy penalty imposed on future > [methane] leakage, if done with careful monitoring and verification, is a > game changer, and can serve as a model for limiting other non-CO₂ > emissions.” > Solar Systems > > A coordinated federal research effort on geoengineering has been a long > time coming. As early as 1965, a study appended to a White House > environmental report found that the warming effects of a carbon dioxide > buildup “could be deleterious” for humanity and urged that “countervailing > climatic changes” be thoroughly explored. Led by oceanographer Roger > Revelle, then director of Harvard’s Center for Population Studies, the > study suggested the Earth could be cooled by increasing the albedo, or > reflectivity, of the earth’s surface. One way to do that, it said, would be > to spread very small reflecting particles over large areas of the ocean. > > The recent NASEM panel called for government-backed research focused on > three sunlight-blocking, or solar radiation modification (SRM), methods. > The first, solar aerosol injection (SAI), involves discharging tiny > particles into the stratosphere, an upper layer of the atmosphere between > 10 and 50 kilometers (6 to 30 miles) above the Earth’s surface. The concept > dates from work published in the mid-1970s by Soviet climatologist Mikhail > Budyko. It gained credibility in a 2006 essay by Paul Crutzen, who shared > the 1995 Nobel Prize in chemistry for discovering how pollutants in the > atmosphere were destroying the ozone layer. SAI is widely considered the > method most likely to work because nature has provided a proof of concept. > Volcanic eruptions spew out huge amounts of ash containing sulfur dioxide. > Lofted to the stratosphere, the sulfur dioxide reacts with water to form a > layer of sulfuric acid droplets that reflect and diffuse incoming sunlight > and radiant heat. When the Philippines’ Mount Pinatubo erupted in 1991, > “stratospheric winds spread these aerosol particles around the globe,” > resulting in “a measurable cooling of the Earth’s surface” for almost two > years, NASA reported in 2001. > > A second SRM method, marine cloud brightening, entails spraying seawater > into low-lying clouds above the ocean to make them more reflective. Cirrus > cloud thinning—a third, less well studied form of cooling—would break up > the delicate strands of ice-crystal clouds above 20,000 feet and let heat > rising from the earth’s surface escape the atmosphere. SRM methods alarm > many environmentalists, primarily for two reasons: 1) they don’t remove the > root cause of climate change, namely the accumulation of greenhouse gases > in the atmosphere and 2) they could ease pressure on societies and > governments to keep cutting emissions. > > OSTP’s anticipated strategy won’t start from scratch; federal support for > geoengineering research has occurred mostly under the radar but hasn’t been > totally lacking. In 2020, Congress provided $4 million to the National > Oceanic and Atmospheric Administration (NOAA) to initiate what the agency > says is “much-needed ‘baseline’ research” on climate intervention > proposals—particularly SAI. Congress upped funding this year to $9 million, > instructing NOAA to expand its efforts and coordinate with NASA and the > Department of Energy (DOE). > > Computer modeling has provided much of what is now known about > geoengineering’s potential and risks. The Intergovernmental Panel on > Climate Change draws from more than two dozen modeling centers for its > climate assessments, but one of the most important is the National Center > for Atmospheric Research (NCAR), sponsored by the National Science > Foundation and headquartered in the Rocky Mountain foothills in Boulder, > Colorado. In addition to providing vital data on the Earth’s climate and > weather, NCAR also serves as a nerve center for geoengineering studies, > enabling global academic collaboration on experiments using ever more > advanced models and a high-performance computer in Cheyenne, Wyoming. > Expect the Unexpected > > The teaming up of NOAA, NASA, and DOE will expand the tools available for > researchers to observe the climate system—such as satellites, balloons, > aircraft capable of reaching the lower stratosphere, and, soon, a > next-generation NCAR supercomputer. The anticipated result: improved > models. But a host of questions remain. “Every time we go up in the > atmosphere and make measurements, we find things we didn’t expect, things > we didn’t know we would see,” says Gregory Frost, a NOAA supervisory > research chemist. > > For instance, scientists know that sulfur dioxide, injected into the > stratosphere, will form aerosols and lower the Earth’s temperature > temporarily—but that’s just a piece of the puzzle, notes NCAR senior > scientist Simone Tilmes, a leader in solar geoengineering research. “We > know we can cool, but we don’t know how much injection we actually need to > cool. There’s still a huge uncertainty on how much you can cool with a > certain amount of injection,” she explains. “We also need to understand the > positive and negative consequences of a possible application [of SAI] and > weigh risks and benefits before any of these [options] should be > considered.” > > As Cornell’s MacMartin puts it, “A lot of the research to date has been > kind of trying things: ‘Hey, we’ll go try this strategy, scenario, climate > model, and we’ll see what happens.’” Over time, the discovery of negative > side effects has prompted modelers to explore ways of tweaking, for > instance, the degree of cooling achieved or location of aerosol injections. > Eventually, MacMartin hopes, scientists will be able to say, “We’ve looked > at the response in a number of different climate models . . . Here’s what > we think will happen. And here’s how confident we are in that assessment.” > > MacMartin, Yale lecturer Wake Smith, and others recently studied the > concept of deploying stratospheric aerosol injection only in subpolar > regions. Such action wouldn’t cool the global climate, but it could halt or > even reverse the melting of Arctic ice that now threatens to cause a > substantial rise in sea levels, the scholars say. > > Live outdoor testing of SAI would buttress existing research with accurate > observations, even if the testing doesn’t answer all the outstanding > questions. But an attempt by Harvard researchers last year showed just how > strong public opposition can be even to research on geoengineering. The > team planned to send up a balloon to release a small quantity of aerosols > into the stratosphere. Following years of preparation, funded in part by > Bill Gates, the team explored various launch venues. Ultimately, it > partnered with the Swedish Space Corporation and made plans to use its base > near Kiruna, Sweden, above the Arctic Circle. The initial flight would > merely test the equipment and not spray any aerosol. But the stratospheric > controlled perturbation experiment (SCoPEx) drew strong local opposition > and was put on hold. The indigenous Sámi people, whose ancestral homeland > stretches across Arctic regions of Sweden, Norway, Finland, and Russia, > joined with Swedish environmental groups to lobby against SCoPEX, citing > “risks of catastrophic consequences, including the impact of uncontrolled > termination, and irreversible sociopolitical effects.” > Lists of Concerns > > “I think the political barriers might be much stronger than the technical > barriers,” says Alan Robock, environmental science professor at Rutgers > University. Renowned for projecting the human, climatic, and ecological > consequences of nuclear war—“We have to solve the problem of nuclear > weapons so we have the luxury of worrying about global warming,” he > says—Robock also applies his forensic research skills to geoengineering. In > 2008 he published “20 Reasons Why Geoengineering May be a Bad Idea.” His > tally of “risks and concerns” has since grown to 28. For SAI, they include > depletion of stratospheric ozone, which helps block harmful ultraviolet > rays; increased ocean acidification; a greater likelihood of droughts in > some parts of the world; the need to keep increasing SAI because existing > particles will grow and become less effective; and the danger of a sudden > warming spike if SAI were ever shut down. “It’s like pulling back on a > spring,” Robock told *The Takeaway,* a public radio talk show. > > As concerns remain about SAI, another proposed method of solar > modification, marine cloud brightening (MCB), engenders a fundamental > question. That is, can you actually brighten clouds? “Clouds are a really > complicated species,” says Robert Wood, a professor of atmospheric sciences > at the University of Washington and principal investigator of a research > collaboration on MCB. The brightening idea originated with British > physicist John Latham, who proposed it two years after starting work on > climate change at NCAR. > > Scientists know that clouds cool the earth’s surface and believe their > reflectivity can be enhanced based on observations of cloud responses to > aerosols emitted in ship exhaust. “Since preindustrial times, human > activity has injected a lot of aerosols and they have exerted a cooling > effect on the planet that partly offsets warming by greenhouse gases,” Wood > says. “So we think it’s feasible.” But, he adds, “the clouds don’t always > do things that you think they’re going to do.” Their internal dynamics are > too fine-grained to show up in climate models. > > Testing of Latham’s theory has begun on Australia’s Great Barrier Reef, a > World Heritage Site where climate change is killing coral. Wood’s team is > planning tests using vessels that spray seawater into the air, forming > particles of salt that would be lofted upward by warm air to low-lying > clouds. Conducted over a limited area of the ocean, the tests would have > minimal environmental impact but yield important information, the group > says. Worldwide, however, MCB’s potential impact is unclear. According to a > 2009 British modeling study, while MCB would slow the pace of global > warming, it could also disrupt rainfall patterns. Some areas would likely > get wetter, others drier—particularly the Amazon rain forest, “a major sink > for carbon dioxide.” > ‘Explore the Edges’ > > The notion of applying space technology to geoengineering has produced > comparatively little research over the years, apart from the growing use of > satellites for climate and atmospheric observations. Among those intrigued > by James Early’s 1989 idea was Edward Teller, the Lawrence Livermore > National Laboratory co-founder who was known as the father of the hydrogen > bomb. In 1997, Teller published the idea of a space-based metallic shield > to scatter sunlight. Another was Colin McInnes, now an aerospace > engineering professor at the University of Glasgow, who read Early’s > article as a PhD student. He went on to develop new approaches to a space > shield, most recently in 2015. “It’s one of these ideas that sticks with > you,” he tells *Prism.* McInnes went on to explore, with Cranford > University colleague Joan-Pau Sánchez, a system of multiple mobile > sunshades in space. This “optimal configuration” would both curb overall > global warming and allow the system to adjust the sunshade effects for > different latitudes and seasons, they wrote. > > McInnes participated in a 2019 Harvard meeting that looked seriously at > various space-based geoengineering schemes. Meeting organizers concluded > that the concept “is not a plausible near-term goal or aspiration.” Still, > he sees value in the research: “What I think is interesting is that [with] > these concepts, you can explore, if you like, the edges of a problem or > where the boundaries might be. And that then gives you a better idea of > where to look for solutions.” > > By not directly interfering in the Earth’s atmosphere, space-based > sunshades “appear to be one of the most efficient methods to tackle climate > change,” McInnes wrote in a paper coathored with Sánchez. The authors > acknowledged that the project would be equivalent in scale to a Three > Gorges Dam—China’s gigantic hydroelectric project—a million miles from > earth and require the manufacture of reflective material equal to a > decade’s worth of aluminum foil. > > The 2021 NASEM report didn’t mention a space-based sunshield among its > recommended federal research topics—a sign that the panel concurs with > Robock’s conclusion that it’s “too expensive, too technologically > questionable.” Of Space Bubbles, Harvard’s Keith says Ratti’s team “has > cool tech, but when I met with them, they did not articulate any sensible > reason, other than just asserting it, why this would be a better pathway > than the existing pathways.” The idea generated press, he asserts, “not > because it’s important but because a story with MIT and space bubbles and > geoengineering was just too sweet to pass up.” > Work in Progress > > Ratti is indeed a newcomer to geoengineering. Until recently, Senseable > City Lab has pursued climate adaptation and mitigation “by optimizing our > built environments and transportation infrastructures,” he says. The > website of his Turin, Italy-based architecture and engineering firm > features two examples: a synergistic pairing of autonomous taxis and a new > skyscraper in Singapore, and large thermal basins floating off Helsinki’s > harbor that serve as hot-water batteries for the city’s heating systems. > Now, Ratti says, “Earth-based climate solutions may not be enough, and more > radical technologies might be needed to address the coming climate > disaster.” > > While Space Bubbles is still a “working hypothesis,” Ratti’s team says it > has simulated thin-film bubbles in outer space conditions and found they > could prove effective at deflecting solar radiation. The spheres could be > made of silicon-based melts or graphene-reinforced ionic liquids. Other > potential composites will be explored. But the team’s concept paper omits > details on how the bubble material reaches space, gets assembled, and is > stabilized. > > The challenge of filling those gaps falls to Ratti and five MIT > colleagues. Two members of the National Academy of Engineering—computer > scientist and roboticist Daniela Rus, winner of a 2002 MacArthur “genius > grant,” and Gareth McKinley, professor of teaching innovation in the > Department of Mechanical Engineering—are joined by Charles Primmerman, a > Lincoln Laboratory high-energy laser expert; materials scientist Markus > Buehler, a specialist in bio-inspired design and in building materials atom > by atom; and aerospace engineer Paulo Lozano, director of the MIT Space > Propulsion Laboratory. Ratti says that “we expect other collaborators to > join us at MIT and beyond.” > > With Space Bubbles, “we aim to develop a fully reversible space-based > solution,” Rus tells *Prism.* MIT’s Computer Science and Artificial > Intelligence Laboratory, which she directs, “will develop the robotic > devices and AI systems that will help control the space bubbles.” > > If fabricating a vast sunshield at L1 still seems like performing the > impossible, McInnes ticks off advances, like reusable vehicles, that are > making space more accessible. > > “If we are able to get much better at space robotics—if we can extract > materials from near-earth asteroids, for example—and if we develop > technologies for manufacturing large structures in space, then you can > imagine a future where all of those different technological strands . . . > come together” to make what now seems like an enormous technical challenge > potentially more feasible, says McInnes. There’s already strong interest in > in-orbit manufacturing, he adds. > Help Wanted > > The biggest hurdle McInnes sees to any kind of geoengineering (space-based > or otherwise)—and the reason he is a skeptic about its implementation—is > governance: “the regulatory challenges of getting international agreement.” > Private groups are working on the problem. They include the Carnegie > Climate Governance Initiative launched by the Carnegie Council for Ethics > in International Affairs, which “seeks to catalyse the creation of > effective governance for climate-altering technologies” and the Global > Commission on Governing Risks from Climate Overshoot, formed to “recommend > a strategy to reduce risks should global warming goals be exceeded.” So > far, governments haven’t been publicly involved. > > Keith, an adviser to the Climate Overshoot Commission’s secretariat, says > the United States and China loom large in any decision to deploy > geoengineering. “If the US and China both clearly want it, then it happens. > Conversely, if they both don’t want it, then it doesn’t.” If neither > superpower stakes out a strong position, “it’s quite possible small > countries could play a big role to determine what happens.” > > If the world fails to meet the challenge of climate change and approaches > catastrophe, humanity might seek a fallback in aerospace engineer Early’s > science fiction plot of some 33 years ago. Venus, anyone? > > *Source*: PRISM > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAOyeF5tF40KDM_S45DjdoF61kc6QAm98MyCNOQE1r9rmM1m%2B7w%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAOyeF5tF40KDM_S45DjdoF61kc6QAm98MyCNOQE1r9rmM1m%2B7w%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CA%2BPtSANLyR2wwED0v8vj7q01DoMmpeuo2S5HFmBrRLG25cp0jA%40mail.gmail.com.
