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:

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:

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:

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:

Abstract: The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate. We use surface weather from three global climate models based on the moderate warming, A1B Intergovernmental Panel on Climate Change emissions scenario and the SiBCASA land surface model to estimate the strength and timing of the PCF and associated uncertainty. By 2200, we predict a 29-59% decrease in permafrost area and a 53-97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190±64 gigatonnes of carbon. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Particularly interesting is the slowing of thermohaline circulation.  In John Nissen's "two scenarios" work there's an uncomfortably cool future—if the Gulf Stream were to be diverted by meltwater flowing into NW Atlantic. There's also an unbearably hot future, if the methane from not-so-permafrost and causes global warming to spiral out of control. So we have a terrifying menu.

JB: I recently interviewed Nathan Urban here. He explained a paper where he estimated the chance that the Atlantic current you're talking about could collapse. (Technically, it's the Atlantic meridional overturning circulation, not quite the same as the Gulf Stream.) They got a 10% chance of it happening in two centuries, assuming a business as usual scenario. But there are a lot of uncertainties in the modeling here.

Back to geoengineering. I want to talk about some ways it could go wrong, how soon we'd find out if it did, and what we could do then.

For example, you say we'll put sulfur dioxide in the atmosphere below 15 kilometers, and most of the ozone is above 20 kilometers. That's good, but then I wonder how much sulfur dioxide will diffuse upwards. As the name suggests, the stratosphere is "stratified" —there's not much turbulence. That's reassuring. But I guess one reason to do experiments is to see exactly what really happens.

GB: It's really the only way to go forward. I fear we are now in the Decade of Dithering that will end with the deadly 2020s. Only then will experiments get done and issues engaged. All else, as tempting as ideas and simulations are, spell delay if they do not couple with real field experiments—from nozzle sizes on up to albedo measures —which finally decide.

JB: Okay. But what are some other things that could go wrong with this sulfur dioxide scheme? I know you're not eager to focus on the dangers, but you must be able to imagine some plausible ones: you're an SF writer, after all. If you say you can't think of any, I won't believe you! And part of good design is looking for possible failure modes.

GB: Plenty can go wrong with so vast an idea. But we can learn from volcanoes, that give us useful experiments, though sloppy and noisy ones, about putting aerosols into the air. Monitoring those can teach us a lot with little expense.

We can fail to get the aerosols to avoid clumping, so they fall out too fast. Or we can somehow trigger a big shift in rainfall patterns—a special danger in a system already loaded with surplus energy, as is already displaying anomalies like the bitter winters in Europe, floods in Pakistan, drought in Darfur. Indeed, some of Alan Robock's simulations of Arctic aerosol use show a several percent decline in monsoon rain—though that may be a plus, since flooding is the #1 cause of death and destruction during the Indian monsoon.

Mostly, it might just plain fail to work. Guessing outcomes is useless, though.  Here's where experiment rules, not simulations. This is engineering, which learns from mistakes. Consider the early days of aviation. Having more time to develop and test a system gives more time to learn how to avoid unwanted impacts. Of course, having a system ready also increases the probability of premature deployment; life is about choices and dangers.  

More important right now than developing capability, is understanding the consequences of deployment of that capability by doing field experiments. One thing we know: both science and engineering advance most quickly by using the dance of theory with experiment. Neglecting this, preferring only experiment, is a fundamental mistake.

JB: Switching gears slightly: in March last year you went to the Asilomar Conference on climate intervention technologies. I've read the report:

It seems unobjectionable and a bit bland, no doubt deliberately so, with recommendations like this:

"Public participation and consultation in research planning and oversight, assessments, and development of decision-making mechanisms and processes must be provided."

What were some interesting things that you learned there? And what'll happen next?

GB: It was the Woodstock of the policy wonks. I found it depressing. Not much actual science got discussed, and most just fearlessly called for more research, forming of panels and committees, etc. This is how bureaucracy digests a problem, turning it quite often into fertilizer.

I'm a physicist who does both theory and experiment. I want to see work that combines those to give us real information and paths to follow. I don't see that anywhere now. Congress might hand out money for it but after the GAO report on geoengineering last September there seems little movement.

I did see some people pushing their carbon capture companies, to widespread disbelief. The simple things we could do right now like our CROPS carbon capture proposal are neglected, while entrepreneur companies hope for a government scheme to pay for sucking CO2 from the air. That'll be the day!—far into the crisis, I think, maybe several decades from now. I also saw fine ideas pushed aside in favor of policy wonk initiatives. It was a classic triumph of process over results. As is many areas dominated by social scientists, people seemed to be saying, "Nobody can blame us if we go through the motions.”

That Decade of Dithering is upon us now. The great danger is that tipping points may not be obvious, even as we cross them. They may present as small events that nonetheless take us over an horizon from which we can never return.

For example, the loss of Greenland ice. Once the ice sheet melts down to an altitude below that needed to maintain it, we've lost it. The melt lubricates the glacier base and starts a slide we cannot stop. There are proposals of how to block that—essentially, draw the water out from the base as fast as it appears—but nobody's funding such studies.  

A reasonable, ongoing climate control program might cost $100 million annually. That includes small field experiments, trials with spraying aerosols, etc. We now spend about $5 billion per year globally studying the problem, so climate control studies would be 1/50 of that.

Even now, we may already be too late for a tipping point—we still barely glimpse the horrors we could be visiting on our children and their grandchildren's grandchildren.

JB: I think a lot of young people are eager to do something. What would be your advice, especially to future scientists and engineers? What should they do? The problems seem so huge, and most so-called "adults" are shirking their responsibilities—perhaps hoping they'll be dead before things get too bad.

GB: One reason people are paralyzed is simple: major interests would get hurt—coal, oil, etc. The fossil fuel industry is the second largest in the world; #1 is agriculture. We have ~50 trillion dollars of infrastructure invested in it. That and inertia—we've made the crucial fuel of our world a Bad Thing, and prohibition never works with free people. Look at the War on Drugs, now nearing its 40th anniversary.

That's why I think adaptation—dikes, water conservation, reflecting roofs and blacktop to cool cities and lower their heating costs, etc.— is a smart way to prepare. We should also fund research in mineral weathering as a way to lock up CO2, which not only consumes CO2 but it can also generate ocean alkalinity. The acidification of the oceans is undeniable, easily measured, and accelerating. Plus geoengineering, which is probably the only fairly cheap, quick way to damp the coming chaos for a while. A stopgap, but we're going to need plenty of those.

JB: And finally, what about you? What are you doing these days? Science fiction? Science? A bit of both?

Both, plus. Last year I published a look at how we viewed the future in the 20th Century, The Wonderful Future We Never Had, and have a novel in progress now cowritten with Larry Niven—about a Really Big Object. Plus some short stories and journalism.

My identical twin brother Jim & I published several papers looking at SETI from the perspective of those who would pay the bills for a SETI beacon, and reached conclusions opposite from what the SETI searches of the last half century have sought. Instead of steady, narrowband signals near 1 GHz, it is orders of magnitude cheaper to radiate pulsed, broadband beacon signals nearer 10 GHz. This suggests new way to look for pulsed signals, which some are trying to find. We may have been looking for the wrong thing all along. The papers are on the arXiv:

For math types, David Wolpert and I have shown that Newcomb's paradox arises from confusions in the statement, so is not a paradox:

JB: The next guest on this show, Eliezer Yudkowsky, has also written about Newcomb's paradox. I should probably say what it is, just for folks who haven't heard yet. I'll quote Yudkowsky's formulation, since it's nice and snappy:

A superintelligence from another galaxy, whom we shall call Omega, comes to Earth and sets about playing a strange little game. In this game, Omega selects a human being, sets down two boxes in front of them, and flies away.

Box A is transparent and contains a thousand dollars.
Box B is opaque, and contains either a million dollars, or nothing.

You can take both boxes, or take only box B.

And the twist is that Omega has put a million dollars in box B if and only if Omega has predicted that you will take only box B.

Omega has been correct on each of 100 observed occasions so far—everyone who took both boxes has found box B empty and received only a thousand dollars; everyone who took only box B has found B containing a million dollars. (We assume that box A vanishes in a puff of smoke if you take only box B; no one else can take box A afterward.)

Before you make your choice, Omega has flown off and moved on to its next game. Box B is already empty or already full.

Omega drops two boxes on the ground in front of you and flies off.

Do you take both boxes, or only box B?

If you say you'd take both boxes, I'll argue that's stupid: everyone who did that so far got just a thousand dollars, while the folks who took only box B got a million!

If you say you'd take only box B, I'll argue that's stupid: there has got to be more money in both boxes than in just one of them!

So, this puzzle has a kind of demonic attraction. Lots of people have written about it, though personally I'm waiting until a superintelligence from another galaxy actually shows up and performs this stunt.

Hmm—I see your paper uses Bayesian networks! I've been starting to think about those lately.

But I know that's not all you've been doing.

GB: I also started several biotech companies 5 years ago, spurred in part by the agonizing experience of watching my wife die of cancer for decades, ending in 2002. They're genomics companies devoted to extending human longevity by upregulating genes we know confer some defenses against cardio, neurological and other diseases. Our first product just came out, StemCell100, and did well in animal and human trials.

So I'm staying busy. The world gets more interesting all the time. Compared with growing up in the farm country of Alabama, this is a fine way to live.

JB: It's been great to hear what you're up to. Best of luck on all these projects, and thanks for answering my questions!


For more discussion go to my blog, Azimuth.

Few doubt that our climate stands in a class by itself in terms of complexity. Though much is made of how wondrous our minds are, perhaps the most complex entity known is our biosphere, in which we are mere mayflies. Absent a remotely useful theory of complexity in systems, we must proceed cautiously. - Gregory Benford


© 2011 John Baez
baez@math.removethis.ucr.andthis.edu