https://www.technologyreview.com/s/407306/cooling-the-planet/

Cooling the Planet
If we can’t adequately reduce or sequester carbon emissions, are more-radical alternatives like orbital mirrors a solution to climate change?
by Mark Williams Pontin
Feb 13, 2007

In the past two decades, various novel planet-cooling technologies have been proposed–improbable, monumental projects such as putting into orbit giant mirrors with thousand-kilometer diameters or clouds of trillions of wafer-thin, butterfly-light lenses. Until recently, such proposals have remained on the fringes of acceptable scientific speculation. Now, with the Intergovernmental Panel on Climate Change (IPCC) claiming in its report of February 3 that there’s a 90 percent probability that the last half-century of global warming has been caused by humans, a milestone moment has apparently arrived. Four hours after the IPCC report’s release, even the White House (historically extremely hostile to the idea of anthropogenic climate change) had unearthed a 2001 remark by President George W. Bush acknowledging that greenhouse-gas increases were largely created by humans. Consequently, while mainstream acceptance of climate change means that the battles over what humanity should do about it are just beginning, radical planet-cooling technological possibilities are receiving consideration alongside the standard proposals for capping, reducing, or sequestering carbon emissions.

The notion of interposing a really big mirror between the Sun and Earth, which exploits the fact that our planet already reflects about 30 percent of incoming sunlight back into space by effectively increasing its reflectivity, dates back to the 1980s. Initially, such mirrors were suggested for cooling Venus as part of a theoretical future effort to terraform that planet. But in 1989, James Early of the Lawrence Livermore National Laboratory noted the harbingers of global warming and proposed deflecting a measure of sunlight with a “space shade” located at Lagrangian Point L1–an orbit 1.5 million kilometers up, where Earth’s gravity and that of the Sun are balanced so an object can remain stationary relative to both bodies.

How big a shield was Early thinking about? One 2,000 kilometers in diameter and about 10 microns thick, with a weight of about 100 megatons under Earth’s gravity. Early’s shield would have been either opaque or else transparent in the form of a Fresnel lens (the kind of lens used in lighthouses, in which the amount of material required is reduced from that needed in a conventional spherical lens because the lens is broken into concentric annular sections). Early estimated the cost at $1 to $10 trillion. As for assembling his giant mirror and placing it at L1, Early suggested using moon rock for the materials and a manufacturing plant on the lunar surface, then launching the components by a mass driver from the Moon to L1.

Given how arduous even minor assembly work on the International Space Station’s exterior has been, and given that NASA will almost certainly be unable to meet its schedule for returning to the Moon by 2020, such a megaconstruction doesn’t seem immediately feasible. Last year Roger Angel, University of Arizona Regents Professor and the Steward Observatory Mirror Laboratory’s director, offered another plan: to place in orbit at L1 a very great number of small, already assembled objects. Angel presented his concept to the National Academy of Sciences in April 2006, got a NASA grant to fund further research, and then published a detailed paper, “Feasibility of Cooling the Earth with a Cloud of Small Spacecraft near L1.”

Angel’s plan calls for small “flyers”: transparent sheets two feet in diameter and 1/5,000 of an inch thick, each weighing approximately one gram under Earth’s gravity. Trillions of these objects, according to Angel, could together form a cylindrical cloud having a diameter half that of Earth’s and a length of 60,000 miles. Interposed lengthwise between the Sun and Earth at L1, this cloud would uniformly reduce sunlight on our planet’s surface by 2 percent, which would be sufficient to offset the warming produced by even a doubling of atmospheric carbon dioxide.

Angel stresses that his plan is an emergency option, for use only if climate change so accelerates that global catastrophe looms within a decade or two. It is, he says, “no substitute for developing renewable energy, the only permanent solution.” It’s just as well that Angel makes that qualification, since he estimates that the total mass of all the flyers composing his cloud would be 20 million tons and a total of 20 electromagnetic launchers. At $10,000 a pound, conventional rockets are a prohibitively expensive way of getting that much mass into orbit. Human beings would have to launch a stack of flyers every five minutes for 10 years to put the whole structure in place.

Gregory Benford, a professor of plasma physics and astrophysics at the University of California, comments, “This whole L1 idea is neat, but it’s going to cost trillions of dollars, we can’t do it right away, and it gets used to label the entire field of geoengineering as smoke and mirrors.” Benford, besides having been an advisor for NASA, the Department of Energy, and the White House Council on Space Policy, has been a science-fiction writer, and he distinguishes carefully between currently feasible technological solutions and the kinds of advanced possibilities that he writes about in his fiction. “These are fun ideas for the year 2,100. But we don’t live there. People don’t quite understand that we will never again in our lifetime see the level of CO2 in the atmosphere that we enjoyed just yesterday. Our grandchildren likely won’t, either.”

What’s to be done? Other scientists have proposed Earth-based environmental megamodifications, such as reflective films laid over the planet’s deserts or fertilizing the seas with iron to create vast blooms of plants that would then consume tons of carbon dioxideand, as the plants died, drag the carbon into the sea. But even these measures are problematical and grandiose when most European and North American environmentalists remain committed to an international regime of carbon emissions caps and reject the idea of radical new technologies to mitigate the climate change that technological society has already created.

On the one hand, such folks do have a point inasmuch as any global modification to the environment that went wrong would be a cure worse than the disease. On the other hand, it seems increasingly unlikely that a global agreement on emissions caps will be enacted anytime soon. The IPCC report claims that there is a high likelihood that Earth’s climate has already moved past the point of no return and that sea levels will continue rising for millennia. Simultaneously, billions of people in China and India are arriving at the First World banquet table: according to the International Energy Agency, in two years China will pass the United States as the largest source of carbon emissions. “The political impossibility of what I call the prohibitionist agenda–that is, carbon prohibitionism–brings a kind of hallucinogenic quality to the global-warming discussion,” says Benford. “No economist I know believes that global carbon emissions can be restrained within a century to even the level we have now. Every economist knows that the timescale for changing energy infrastructure is at least half a century to a century, just because of replacement costs. Economists are scientists to
o, and ignoring them isn’t just blind: it’s perverse.”

Benford has a proposal that possesses the advantages of being both one of the simplest planet-cooling technologies so far suggested and being initially testable in a local context. He suggests suspension of tiny, harmless particles (sized at one-third of a micron) at about 80,000 feet up in the stratosphere. These particles could be composed of diatomaceous earth. “That’s silicon dioxide, which is chemically inert, cheap as earth, and readily crushable to the size we want,” Benford says. This could initially be tested, he says, over the Arctic, where warming is already considerable and where few human beings live. Arctic atmospheric circulation patterns would mostly confine the deployed particles around the North Pole. An initial experiment could occur north of 70 degrees latitude, over the Arctic Sea and outside national boundaries. “The fact that such an experiment is reversible is just as important as the fact that it’s regional,” says Benford.

Is Benford’s proposal realistic? According to Ken Caldeira, a leading climate scientist at Stanford University and the Carnegie Institution’s Department of Global Ecology, “It appears as if any small particle would do the trick in the necessary quantities. I’ve done a number of computer simulations of what the climate response would be of reflecting sunlight, and all of them indicate that it would work quite well.” He adds, “I wouldn’t look to these geoengineering schemes as part of normal policy response, but if bad things start to happen quickly, then people will demand something be done quickly.”

Given that our social systems would crash without the economic growth that depends on the existing energy infrastructure that we have, Benford personally believes that governments can’t be counted on to develop and deploy alternatives: “Anybody who thinks governments are suddenly going to leap into action is dreaming.” Benford says that one of the advantages of his scheme is that it could be implemented unilaterally by private parties. “Applying these technologies in the Arctic zone or even over the whole planet would be so cheap that many private parties could do it on their own. That’s really a dangerous idea because it suggests the primary actor in this drama will not be the nation-state anymore. You could do this for a hundred million bucks a year. You could do the whole planet for a couple of billion. That’s amazingly cheap.”

http://math.ucr.edu/home/baez/week310.html

a really interesting interview:

February 27, 2011
This Week's Finds (Week 310)
John Baez
I first encountered Gregory Benford through his science fiction novels: my favorite is probably In the Ocean of Night.

Later I learned that he's an astrophysicist at U.C. Irvine, not too far from Riverside where I teach. But I only actually met him through my wife. She sometimes teaches courses on science fiction, and like Benford, she has some involvement with the Eaton Collection at U.C. Riverside—the largest publicly accessible SF library in the world. So, I was bound to eventually bump into him.

When I did, I learned about his work on electromagnetic filaments near the center of our galaxy—see "week252" for more. I also learned he was seriously interested in climate change, and that he was going to the Asilomar International Conference on Climate Intervention Technologies—a controversial get-together designed to hammer out some policies for research on geoengineering.

Benford is a friendly but no-nonsense guy. Recently he sent me an email mentioning my blog, and said: "Your discussions on what to do are good, though general, while what we need is specifics NOW." Since I'd been meaning to interview him for a while, this gave me the perfect opening.

JB: You've been thinking about the future for a long time, since that's part of your job as a science fiction writer. For example, you've written a whole series about the expansion of human life through the galaxy. From this grand perspective, global warming might seem like an annoying little road-bump before the ride even gets started. How did you get interested in global warming?

GB: I liked writing about the far horizons of our human prospect; it's fun. But to get even above the envelope of our atmosphere in a sustained way, we have to stabilize the planet. Before we take on the galaxy, let's do a smaller problem.

JB: Good point. We can't all ship on out of here, and the way it's going now, maybe none of us will, unless we get our act together.

Can you remember something that made you think "Wow, global warming is a really serious problem"? As you know, not everyone is convinced yet.

GB: I looked at the migration of animals and then the steadily northward march of trees. They don't read newspapers—the trees become newspapers—so their opinion matters more. Plus the retreat of the Arctic Sea ice in summer, the region of the world most endangered by the changes coming. I first focused on carbon capture using the CROPS method. I'm the guy who first proposed screening the Arctic with aerosols to cool it in summer.

JB: Let's talk about each in turn. "CROPS" stands for Crop Residue Oceanic Permanent Sequestration. The idea sounds pretty simple: dump a lot of crop residues—stalks, leaves and stuff—on the deep ocean floor. That way, we'd be letting plants suck CO2 out of the atmosphere for us.

GB: Agriculture is the world's biggest industry; we should take advantage of it. That's what gave Bob Metzger and me the idea: collect farm waste and sink it to the bottom of the ocean, whence it shall not return for 1000 years. Cheap, easy, doable right now.

JB: But we have to think about what'll happen if we dump all that stuff into the ocean, right? After all, the USA alone creates half a gigatonne of crop residues each year, and world-wide it's ten times that. I'm getting these numbers from your papers:

Robert A. Metzger and Gregory Benford, Sequestering of atmospheric carbon through permanent disposal of crop residue, Climatic Change 49 (2001), 11-19.

Stuart E. Strand and Gregory Benford, Ocean sequestration of crop residue carbon: recycling fossil fuel carbon back to deep sediments, Environmental Science and Technology 43 (2009), 1000-1007.

Since we're burning over 7 gigatonnes of carbon each year, burying 5 gigatonnes of crop waste is just enough to make a serious dent in our carbon footprint. But what'll that much junk do at the bottom of the ocean?

GB: We're testing the chemistry of how farm waste interacts with deep ocean sites offshore Monterey Bay right now. Here's a picture of a bale 3.2 km down:

JB: I'm sure our audience will have more questions about this... but the answers to some are in your papers, and I want to spend a bit more time on your proposal to screen the Arctic. There's a good summary here:

Gregory Benford, Climate controls, Reason Magazine, November 1997.

But in brief, it sounds like you want to test the results of spraying a lot of micron-sized dust into the atmosphere above the Arctic Sea during the summer. You suggest diatomaceous earth as an option, because it's chemically inert: just silica. How would the test work, exactly, and what would you hope to learn?

GB: The US has inflight refueling aircraft such as the KC-10 Extender that with minor changes spread aerosols at relevant altitudes, and pilots who know how to fly big sausages filled with fluids.

Rather than diatomaceous earth, I now think ordinary SO2 or H2S will work, if there's enough water at the relevant altitudes. Turns out the pollutant issue is minor, since it would be only a percent or so of the SO2 already in the Arctic troposphere. The point is to spread aerosols to diminish sunlight and look for signals of less sunlight on the ground, changes in sea ice loss rates in summer, etc. It's hard to do a weak experiment and be sure you see a signal. Doing regional experiments helps, so you can see a signal before the aerosols spread much. It's a first step, an in-principle experiment.

Simulations show it can stop the sea ice retreat. Many fear if we lose the sea ice in summer ocean currents may alter; nobody really knows. We do know that the tundra is softening as it thaws, making roads impassible and shifting many wildlife patterns, with unforeseen long term effects. Cooling the Arctic back to, say, the 1950 summer temperature range would cost maybe $300 million/year, i.e., nothing. Simulations show to do this globally, offsetting say CO2 at 500 ppm, might cost a few billion dollars per year. That doesn't help ocean acidification, but it's a start on the temperature problem.

JB: There's an interesting blog on Arctic political, military and business developments:

Anatoly Karlin, Arctic Progress.

Here's the overview:

Today, global warming is kick-starting Arctic history. The accelerating melting of Arctic sea ice promises to open up circumpolar shipping routes, halving the time needed for container ships and tankers to travel between Europe and East Asia. As the ice and permafrost retreat, the physical infrastructure of industrial civilization will overspread the region [...]. The four major populated regions encircling the Arctic Ocean—Alaska, Russia, Canada, Scandinavia (ARCS)—are all set for massive economic expansion in the decades ahead. But the flowering of industrial civilization's fruit in the thawing Far North carries within it the seeds of its perils. The opening of the Arctic is making border disputes more serious and spurring Russian and Canadian military buildups in the region. The warming of the Arctic could also accelerate global warming—and not just through the increased economic activity and hydrocarbons production. One disturbing possibility is that the melting of the Siberian permafrost will release vast amounts of methane, a greenhouse gas that is far more potent than CO2, into the atmosphere, and tip the world into runaway climate change.

But anyway, unlike many people, I'm not mentioning risks associated with geoengineering in order to instantly foreclose discussion of it, because I know there are also risks associated with not doing it. If we rule out doing anything really new because it's too expensive or too risky, we might wind up locking ourselves in a "business as usual" scenario. And that could be even more risky—and perhaps ultimately more expensive as well.

GB: Yes, no end of problems. Most impressive is how they look like a descending spiral, self-reinforcing.

Certainly countries now scramble for Arctic resources, trade routes opened by thawing—all likely to become hotly contested strategic assets. So too melting Himalayan glaciers can perhaps trigger "water wars" in Asia—especially India and China, two vast lands of very different cultures. Then, coming on later, come rising sea levels. Florida starts to go away. The list is endless and therefore uninteresting. We all saturate.

So droughts, floods, desertification, hammering weather events—they draw ever less attention as they grow more common. Maybe Darfur is the first "climate war." It's plausible.

The Arctic is the canary in the climate coalmine. Cutting CO2 emissions will take far too long to significantly affect the sea ice. Permafrost melts there, giving additional positive feedback. Methane release from the not-so-perma-frost is the most dangerous amplifying feedback in the entire carbon cycle. As John Nissen has repeatedly called attention to, the permafrost permamelt holds a staggering 1.5 trillion tons of frozen carbon, about twice as much carbon as is in the atmosphere. Much would emerge as methane. Methane is 25 times as potent a heat-trapping gas as CO2 over a century, and 72 times as potent over the first 20 years! The carbon is locked in a freezer. Yet that's the part of the planet warming up the fastest. Really bad news:

Kevin Schaefer, Tingjun Zhang, Lori Bruhwiler and Andrew P. Barrett, Amount and timing of permafrost carbon release in response to climate warming, Tellus, 15 February 2011.

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To: 234802398409
Humanity can not predict the weather next monday and I am supposed to
believe we can predict the next 50 years?

We had ''global cooling'' in the 1970s and scientists saying multiple
large cities in the U.S. will be underwater in 30 years.

Start paying your church tithe, sorry, I mean carbon tax.
--
Posted on RetroBBS

>Start paying your church tithe, sorry, I mean carbon tax.

It will be used for that, no doubt. But that does not make climate change less real. If you don't believe the scientists, believe the people from the insurance business and look at the development of the payouts for large scale stuff like storms and floodings.
Posted on def3

Guest wrote on Fri, 11 October 2019 18:41
> >Start paying your church tithe, sorry, I mean carbon tax.
>
> It will be used for that, no doubt. But that does not make climate change less real. If you don't believe the scientists, believe the people from the insurance business and look at the development of the payouts for large scale stuff like storms and floodings.

I've watched the climate change over just my 50+ short years (short in relation to earth changes), and I've lived where it used to flood like crazy, then went dry for many years, now floods a lot again. I'm convinced that climate change is real. It's measurable (somewhat) and even over half a century one person can see changes.

Where I'm not convinced is that it is man (or woman) caused. The statments like, "Don't you see that the climate is changing?" What about some particular recent disaster?" are not something that necessarily means people cause it. It may be man caused, but pointing out the changes in climate doesn't really prove man caused.

I once watched a car drive straight across a busy road and run into the side of a truck. My thought was, did the driver have some sort of attack? He didn't even try to stop. Then I find that the car rolled out of a car park, no one was in it, but of course my first obvious thought was "who did this dumb thing? (must be man caused)
Posted on def3

I agree, it is impossible to attribute a single occurrence like a flooding or storm to something that the human race has done. It is different though if you take a more global perspective and look at averages and the big developments.
In the scientific community, a vast majority of the studies find that human influence is the main driver behind the current climate change (think it was something like 95% or so, I would have to dig out the link again).
Posted on def3

the military in the west is preparing for the climate change, too:

https://www.nato.int/cps/en/natohq/news_57793.htm
Posted on def2

You have about 16-17 years for the species as you know it. The oxygen levels will fall bellow 19% and most humans will be toast. I guess you could get rid of farms in tropical areas and plant hemph... you cant't harvest. One of the biggest recent culprits is the Norwegian Hedge Fund that distroed Malaesia and Indonesia with Palm Oil. If you live that long you will see.
Posted on def3

It is actually worse. We have to do a lot of stuff now, and fast, if we want to preserve life on earth as we know it.

https://www.theguardian.com/environment/2019/jun/18/arctic-permafrost-canada-science-climate-crisis

Scientists shocked by Arctic permafrost thawing 70 years sooner than predicted

Ice blocks frozen solid for thousands of years destabilized
‘The climate is now warmer than at any time in last 5,000 years’

Reuters

Tue 18 Jun 2019 17.02 BST
Last modified on Tue 18 Jun 2019 17.58 BST

A cemetery sitting on melting permafrost tundra at the village of Quinhagak on the Yukon Delta in Alaska.The scientists’ findings offer a further sign of a growing climate emergency.
A cemetery sitting on melting permafrost tundra at the village of Quinhagak on the Yukon delta in Alaska. The scientists’ findings offer a further sign of a climate emergency. Photograph: Mark Ralston/AFP/Getty Images

Permafrost at outposts in the Canadian Arctic is thawing 70 years earlier than predicted, an expedition has discovered, in the latest sign that the global climate crisis is accelerating even faster than scientists had feared.

A team from the University of Alaska Fairbanks said they were astounded by how quickly a succession of unusually hot summers had destabilised the upper layers of giant subterranean ice blocks that had been frozen solid for millennia.

“What we saw was amazing,” Vladimir Romanovsky, a professor of geophysics at the university, told Reuters. “It’s an indication that the climate is now warmer than at any time in the last 5,000 or more years.“
Canada warming at twice the global rate, climate report finds
Read more

With governments meeting in Bonn this week to try to ratchet up ambitions in United Nations climate negotiations, the team’s findings, published on 10 June in Geophysical Research Letters, offered a further sign of a growing climate emergency.

The paper was based on data Romanovsky and his colleagues had been analysing since their last expedition to the area in 2016. The team used a modified propeller plane to visit exceptionally remote sites, including an abandoned cold war-era radar base more than 300km from the nearest human settlement.

Diving through a lucky break in the clouds, Romanovsky and his colleagues said they were confronted with a landscape that was unrecognisable from the pristine Arctic terrain they had encountered during initial visits a decade or so earlier.

The vista had dissolved into an undulating sea of hummocks – waist-high depressions and ponds known as thermokarst. Vegetation, once sparse, had begun to flourish in the shelter provided from the constant wind.

Torn between professional excitement and foreboding, Romanovsky said the scene had reminded him of the aftermath of a bombardment.

“It’s a canary in the coalmine,” said Louise Farquharson, a postdoctoral researcher and co-author of the study. “It’s very likely that this phenomenon is affecting a much more extensive region and that’s what we’re going to look at next.“

Scientists are concerned about the stability of permafrost because of the risk that rapid thawing could release vast quantities of heat-trapping gases, unleashing a feedback loop that would in turn fuel even faster temperature rises.
The end of the Arctic as we know it
Read more

Even if current commitments to cut emissions under the 2015 Paris agreement are implemented, the world is still far from averting the risk that these kinds of feedback loops will trigger runaway warming, according to models used by the UN-backed Intergovernmental Panel on Climate Change.

With scientists warning that sharply higher temperatures would devastate the global south and threaten the viability of industrial civilisation in the northern hemisphere, campaigners said the new paper reinforced the imperative to cut emissions.

“Thawing permafrost is one of the tipping points for climate breakdown and it’s happening before our very eyes,” said Jennifer Morgan, executive director of Greenpeace International. “This premature thawing is another clear signal that we must decarbonise our economies, and immediately.”

Posted on def4

and some fitting info:
https://siberiantimes.com/ecology/others/news/more-than-two-million-hectares-on-fire-in-siberia-with-turndra-on-fire-destryoing-the-permafrost/

see pic with russian city covered in smoke from wildfires all over russia (with old picture to show original look without smoke).

Posted on def4