Al Gore writes:
It would be an enormous relief if the recent attacks on the science of global warming actually indicated that we do not face an unimaginable calamity requiring large-scale, preventive measures to protect human civilization as we know it.For the rest, see:
Of course, we would still need to deal with the national security risks of our growing dependence on a global oil market dominated by dwindling reserves in the most unstable region of the world, and the economic risks of sending hundreds of billions of dollars a year overseas in return for that oil. And we would still trail China in the race to develop smart grids, fast trains, solar power, wind, geothermal and other renewable sources of energy — the most important sources of new jobs in the 21st century.
But what a burden would be lifted! We would no longer have to worry that our grandchildren would one day look back on us as a criminal generation that had selfishly and blithely ignored clear warnings that their fate was in our hands. We could instead celebrate the naysayers who had doggedly persisted in proving that every major National Academy of Sciences report on climate change had simply made a huge mistake.
I, for one, genuinely wish that the climate crisis were an illusion. But unfortunately, the reality of the danger we are courting has not been changed by the discovery of at least two mistakes in the thousands of pages of careful scientific work over the last 22 years by the Intergovernmental Panel on Climate Change. In fact, the crisis is still growing because we are continuing to dump 90 million tons of global-warming pollution every 24 hours into the atmosphere — as if it were an open sewer.
It is true that the climate panel published a flawed overestimate of the melting rate of debris-covered glaciers in the Himalayas, and used information about the Netherlands provided to it by the government, which was later found to be partly inaccurate. In addition, e-mail messages stolen from the University of East Anglia in Britain showed that scientists besieged by an onslaught of hostile, make-work demands from climate skeptics may not have adequately followed the requirements of the British freedom of information law.
But the scientific enterprise will never be completely free of mistakes. What is important is that the overwhelming consensus on global warming remains unchanged. It is also worth noting that the panel's scientists — acting in good faith on the best information then available to them — probably underestimated the range of sea-level rise in this century, the speed with which the Arctic ice cap is disappearing and the speed with which some of the large glacial flows in Antarctica and Greenland are melting and racing to the sea.
Because these and other effects of global warming are distributed globally, they are difficult to identify and interpret in any particular location. For example, January was seen as unusually cold in much of the United States. Yet from a global perspective, it was the second-hottest January since surface temperatures were first measured 130 years ago.
Similarly, even though climate deniers have speciously argued for several years that there has been no warming in the last decade, scientists confirmed last month that the last 10 years were the hottest decade since modern records have been kept.
The heavy snowfalls this month have been used as fodder for ridicule by those who argue that global warming is a myth, yet scientists have long pointed out that warmer global temperatures have been increasing the rate of evaporation from the oceans, putting significantly more moisture into the atmosphere — thus causing heavier downfalls of both rain and snow in particular regions, including the Northeastern United States. Just as it's important not to miss the forest for the trees, neither should we miss the climate for the snowstorm.
Here is what scientists have found is happening to our climate: man-made global-warming pollution traps heat from the sun and increases atmospheric temperatures. These pollutants — especially carbon dioxide — have been increasing rapidly with the growth in the burning of coal, oil, natural gas and forests, and temperatures have increased over the same period. Almost all of the ice-covered regions of the Earth are melting — and seas are rising. Hurricanes are predicted to grow stronger and more destructive, though their number is expected to decrease. Droughts are getting longer and deeper in many mid-continent regions, even as the severity of flooding increases. The seasonal predictability of rainfall and temperatures is being disrupted, posing serious threats to agriculture. The rate of species extinction is accelerating to dangerous levels.
Though there have been impressive efforts by many business leaders, hundreds of millions of individuals and families throughout the world and many national, regional and local governments, our civilization is still failing miserably to slow the rate at which these emissions are increasing — much less reduce them.
And in spite of President Obama's efforts at the Copenhagen climate summit meeting in December, global leaders failed to muster anything more than a decision to "take note" of an intention to act.
Because the world still relies on leadership from the United States, the failure by the Senate to pass legislation intended to cap American emissions before the Copenhagen meeting guaranteed that the outcome would fall far short of even the minimum needed to build momentum toward a meaningful solution.
The political paralysis that is now so painfully evident in Washington has thus far prevented action by the Senate — not only on climate and energy legislation, but also on health care reform, financial regulatory reform and a host of other pressing issues.
This comes with painful costs. China, now the world's largest and fastest-growing source of global-warming pollution, had privately signaled early last year that if the United States passed meaningful legislation, it would join in serious efforts to produce an effective treaty. When the Senate failed to follow the lead of the House of Representatives, forcing the president to go to Copenhagen without a new law in hand, the Chinese balked. With the two largest polluters refusing to act, the world community was paralyzed.
Some analysts attribute the failure to an inherent flaw in the design of the chosen solution — arguing that a cap-and-trade approach is too unwieldy and difficult to put in place. Moreover, these critics add, the financial crisis that began in 2008 shook the world's confidence in the use of any market-based solution.
But there are two big problems with this critique: First, there is no readily apparent alternative that would be any easier politically. It is difficult to imagine a globally harmonized carbon tax or a coordinated multilateral regulatory effort. The flexibility of a global market-based policy — supplemented by regulation and revenue-neutral tax policies — is the option that has by far the best chance of success. The fact that it is extremely difficult does not mean that we should simply give up.
Second, we should have no illusions about the difficulty and the time needed to convince the rest of the world to adopt a completely new approach. The lags in the global climate system, including the buildup of heat in the oceans from which it is slowly reintroduced into the atmosphere, means that we can create conditions that make large and destructive consequences inevitable long before their awful manifestations become apparent: the displacement of hundreds of millions of climate refugees, civil unrest, chaos and the collapse of governance in many developing countries, large-scale crop failures and the spread of deadly diseases.
Dear Professor BaezI replied:
I've read this weeks finds for years and would like to start by thanking you for them. It's a pity that after so long reading and enjoying your stuff I'm only now writing for the first time, and it's to say something negative. I'm sorry about that, I guess it's just human nature, or maybe it's just my nature. Anyway...
There is a serious problem with the piece by Al Gore that you posted. It is true that no amount of leaked emails from CRU can prove that AGW is either not happening or not a problem. However these emails do show something very disturbing. Gore describes the problem as "at least two mistakes in the thousands of pages of careful scientific work" by scientists "acting in good faith". Unfortunately that will not stand. The emails reveal a culture of advocacy at the highest levels of climate science, where the need for objectivity and total honesty has been replaced by the need to find "the right balance between being effective and being honest", where independent scrutiny of published work has been obstructed and the peer review system tampered with to suppress dissenting views. This is not a small matter. I can't put it any better than have the Institute of Physics in their submission to the UK Parliamentary Committee currently investigating the matter:
The Institute is concerned that, unless the disclosed e-mails are proved to be forgeries or adaptations, worrying implications arise for the integrity of scientific research in this field and for the credibility of the scientific method as practised in this context.
Because this scandal provides plenty of ammunition for anyone who opposes action to curb carbon emissions there has been a tendency to downplay it amongst those who remain convinced of the need for such action. That is what Al Gore is doing in the piece you posted, and by posting it without any critical commentary you are supporting him in this. He isn't a scientist, but you are and I think you should be careful about the practices you give the impression of supporting.
Thanks again for years of good reading.
I haven't been following the controversy very carefully. I agree it's not a small matter, and I guess you're right that Al Gore was downplaying a crucial point: the conflict between objectivity and advocacy.
I think it's almost unavoidable, when people discover — or, to take a very distanced viewpoint: "think they discover" — that a crisis is underway, that they will start acting in a way that's less objective and more focused on tackling the problem. For a great example, consider the Manhattan project, where lots of great physicists switched from doing physics to creating a weapon, and some later regretted it.
So, I suspect this problem won't go away. People will need to figure out intelligent ways to address it. And I'll need to address it myself, since I'm planning to switch from working on "quantum gravity and n-categories" over to science with a more practical edge.
But of course I do think that global warming is a serious problem,
that we're in a car
with bad breaks driving towards a cliff in the fog,
and that Al Gore is 100% right to spend tons of energy trying to
wake up the world before it's too late.
March 4, 2010
Here's a nice rough way to understand the effects of various
amounts of carbon dioxide in the atmosphere, taken from the
Stern Review on the Economics of Climate Change.
that MIT scientists estimate that in a business-as-usual
scenario, by 2095 there will be about 890 parts per million of
CO2 in the atmosphere, and a 90% chance of a
temperature increase between 3.5 and 7.3 degrees Celsius,
with a median estimate of 5°. That's on the high end of this
March 5, 2010
Read how bird feeders may create a new species of birds:
Being Wise With Rain RunoffJanet Zimmerman, Riverside Press-Enterprise
February 8, 2010
Long before Southern California's water supplies dwindled, storm runoff was something to be disposed of quickly by sending it down concrete channels to the ocean.
But no more, say water officials who are coping with shortages caused by drought, population growth and environmental restrictions on imports. They want to capture every drop, especially during intense storms like those in January that dumped more than 3 inches of rain in many Inland areas.
"Our 20th century thinking was, 'Storm water bad, flood water even worse.' We're now saying that's water we desperately need," said Celeste Cantu, general manager of the Santa Ana Watershed Project Authority, which plans and builds facilities to protect the water quality of the drainage basin that starts in the San Bernardino Mountains.
Capturing 100 percent of the runoff from all but the most torrential storms would increase the local supply by about 25 percent, said Richard Atwater, general manager of the Inland Empire Utilities Agency in Chino.
That would be enough to save up to $200 million on imported water over the next decade in Riverside and San Bernardino counties, he said, and the savings would be passed along to customers on their water bills.
Efforts to harvest runoff are growing.
Water agencies are expanding their use of holding ponds that allow water to percolate into the ground and recharge aquifers for later use. And more cities and counties are mandating green building construction that catches excess water in on-site cisterns or rain barrels and uses less paving, a large contributor to runoff.
One of the most significant projects includes improvements on the Santa Ana River, south of the Seven Oaks Dam near Highland, that allow the capture of trillions of gallons of water once lost to Orange County.
In the Chino groundwater basin, which includes parts of Riverside and San Bernardino counties, about $50 million has been spent in the past decade to expand spreading grounds that allow runoff to seep into the soil, Atwater said. The district captures enough rain to supply about 6,000 families for a year.
Such projects represent progress, but officials say much more needs to be done, both regionally and at the individual level with improvements such as barrels to catch rain at homes.
"We don't do a very good job with conservation, recycling or storm water management, all supplies that can be used for irrigation, dust control, fire suppression and can be treated and injected back into aquifers. We have a long way to go," said Wendy Martin, state Department of Water Resources drought coordinator.
"We as a society need to demand that our water be treated with respect, and captured and used and used and used," she said.
Need Drives Change
At the Frontier Project in Rancho Cucamonga, parking lots and walkways are made of permeable materials so that water percolates into the ground. Excess surface water is naturally cleansed in slender ditches, called swales, which direct runoff to an underground cistern for irrigating the landscape.
The building, part of a movement known as low-impact development, was finished late last year by the Cucamonga Valley Water District.
The headquarters of the Inland Empire Utilities Agency has similar features, including porous concrete and a 20-acre wetlands park fed by storm water.
"Partly why all this is changing, we're not getting more from the Colorado River, there's gridlock in the (Sacramento-San Joaquin) Delta and imported water is too expensive," Atwater said.
"Fifty years ago when the area was growing rapidly, if we had had rain barrels and designed new homes so the water stayed on site, we'd be a lot better off," he said.
The Riverside County Flood Control and Water Conservation District is also thinking capture.
In Temescal Canyon between Lake Elsinore and Corona, the district wants to purchase land in the floodplain to prevent development and protect the natural percolation and water quality there, said Steve Thomas, assistant chief engineer.
In recent years, his agency and others also have begun to rethink the concrete-lined channels that whisk water away from cities.
Earthen bottoms allow water to sink back into the ground and now are used when possible, he said. But retrofitting most channels isn't an option because housing is built right to the edge, leaving no safety margin for overflow.
The Santa Ana River carries snowmelt from the San Bernardino Mountains and storm runoff through nearly 100 miles of urban areas.
Improvements recently were finished on the Cuttle Weir, a small, dam-like structure a half-mile from Seven Oaks Dam that will double the amount of river water that can be diverted. The work allows local districts to catch an additional 300 acre-feet of water per day during peak runoff. One acre-foot of water can supply two average households for a year.
The water will be used to recharge the Bunker Hill Basin, which supplies San Bernardino Valley and the city of Riverside.
Under an agreement with the state, Orange County is entitled to 42,000 acre-feet of Santa Ana River water per year but had been receiving more like 190,000 acre-feet annually because the water wasn't being captured upstream, said John Rossi, general manager at Western Municipal Water District in Riverside.
Another plan to use more of the Santa Ana River is in the works by the city of Riverside, which wants to stretch a 700-foot-wide inflatable rubber dam across the water near Colton. Some water would be stored behind the 8-foot-tall dam so it could percolate into the ground, and some would flow into holding ponds on the west side of Interstate 215, south of Interstate 10.
The project would catch enough water to supply up to 24,000 families for a year, according to city planning documents.
They make for good reading, though I'm not endorsing all the conclusions! It's a bit sad that the world needs to learn its thermodynamics from a druid who talks about "exergy". Indeed, I'd never even heard of exergy before, so I initially guessed it was a synonym for Gibbs free energy. But Greer is smart enough to be interesting, and apparently exergy is a slight generalization of Gibbs free energy that includes chemical potentials. So, I can see why it deserves a catchy name. In simple terms, it's "the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir."
In the discussion of Greer's first post, William T writes:
I think that one of the problems we have today is that we (in general) have no idea how concentrated the energy in fossil fuels really is. For instance, I recently came across a calculation that really astounded me. That is, the amount of energy being delivered into your car by the petrol bowser (assuming it pumps out at 1 L/s which is about the maximum rate they do) is equivalent to the full output of a 30MW power station - a reasonable sized hydro station. So to fill your car you're taking the full output of a small power station for about 1 minute.John Greer writes:
People don't realize, to give another example, that when a plane full of tourists flies from LA to Cairo so they can visit the Great Pyramid, that one flight uses as much energy as it took to build the Great Pyramid.I haven't checked these calculations, and I should. But they don't seem ridiculous to me. I remember being shocked as a kid when my uncle, the physicist Albert Baez, told me that to heat a bathtub of water to a nice hot temperature takes as much energy as lifting that water to a ridiculous height. But by now it seems obvious: heating things a little means speeding up molecules a fair amount. Heat is random motion of molecules, but if they were all moving the same direction, you'd see how fast they were going.
Let's do the math. By definition, it takes one kilocalorie to raise the temperature of one kilogram of water by 1 degree Celsius. But a kilocalorie is 4184 joules. Kinetic energy goes like mv2/2, and here the mass is 1, so we've got v2/2 = 4184 (meters/second)2, or v = √8368 meters/second = 91 meters/second.
So using the energy it takes to raise water one degree, we could also shoot it out of a cannon at a speed of 91 meters per second! That's about 200 miles per hour, for us Americans, or 325 kilometers per hours, for Europeans. And if we think how much energy goes into waste heat when driving a car, or flying an airplane from here to Egypt... well, then the above remarks don't seem ridiculous. But I should do the calculations myself sometime.
There's a lot of talk about this book by Greer:
If you've been following the peak oil debate, you're well aware of Greer's mantra. In discussions about the future of industrial society, Greer has long complained, too many people remain fixated on only two possible outcomes: business as usual and imminent apocalypse. People cling to these two polar opposites because of how well they jibe with existing cultural narratives — namely the myth of progress and the myth of apocalypse — that exert tremendous emotional power over us. But there are a vast number of middle-ground scenarios in between these two extremes, and these latter possibilities represent the most likely future course of our civilization.Here's my gut reaction. I think it's great to envision scenarios that lie between utopia and apocalypse. And I think we can learn something by examining the past, even though the future will be different in some important ways. I would love to read a careful analysis of declining civilizations. I wouldn't be at all surprised if they typically feature a "gradual, downward stairstep of repeated crises and recoveries". I've read extensively on the decline and fall of the Roman Empire, and it's a haunting and compelling story precisely because of this pattern. I can easily imagine that civilization as we know it will undergo such a "long descent" or "catabolic collapse" as we pass the phase of peak oil— but apparently unlike Greer, I can easily imagine this collapse being averted for a long, long time by switching to nuclear power.
The middle ground that Greer foresees is a period of glacial deterioration that he calls The Long Descent, driven by a process that he refers to as catabolic collapse.
The Long Descent is Greer's attempt to help the average reader make sense of this coming age of decline. He begins the book with a bit of background on peak oil, the Club of Rome's The Limits to Growth study, some lessons from past societal collapses and the difference between problems (which are solvable) and predicaments (which aren't). He makes a strong case for peak oil being a predicament rather than a problem.
Having laid down this background material, Greer then explores the habits of mind that blind us to our predicament. He explains why the myth of progress and that of apocalypse truly are myths (they're literally no different from those once circulated among ancient cultures), and warns of the dangers inherent in continuing to force the proverbial round pegs of reality into the square holes of our myths of choice.
Drawing on the theory of catabolic collapse touched on earlier, Greer next outlines in detail how our predicament is likely to play out during the decades and centuries ahead. Greer's theory of catabolic collapse — well-known within peak oil circles— shows how civilizations headed for collapse tend to decline in a gradual, downward stairstep of repeated crises and recoveries. They don't undergo the sudden, catastrophic free fall envisioned by diehard peak oil doomers. This theory makes for truly fascinating reading, and is included in its entirety as an appendix.
How will our own society's catabolic collapse proceed? Greer sees us on the verge of a couple of decades of economic contraction, chronic energy shortages, declining public health, political turmoil and vanishing knowledge and cultural heritage. This crisis period, he predicts, will be followed by a respite of perhaps 25 years or so, during which industrial civilization's newfound relief from the lavish energy demands of universal motoring and electrification, climate-controlled buildings, modern medicine and other present-day amenities will buy it a little breathing room. But this respite will, in turn, be followed by another round of crises that will rid our civilization of further layers of social complexity, and so on.
Eventually, the developed world will assume an agrarian lifestyle built around local communities and sustainable resources. But this change will happen so slowly that no one alive today will be around to witness the end result. Thus, Greer maintains, our energies should be focused not on surviving the end of industrial civilization, but on making it through the imminent crisis period that will be but one brief interval within that larger context.
To this end, Greer lays out some strategies and technologies for weathering the coming decades of crisis. The appropriate response to the challenges we face, Greer believes, is not to set up survivalist enclaves or lifeboat communities, but to reshape our existing cities, towns and rural neighborhoods in order to better meet those challenges. Greer sees renewed participation in fraternal orders like the Freemasons and Odd Fellows as a vital part of restoring the former institutions of civil society that so successfully weathered past periods of dramatic social change.
On an individual level, everyone needs to sharply curtail energy usage and find low-tech ways of doing things, in order to prepare for the inevitable shortages. We also need to position ourselves into occupational niches that meet actual human needs, since these are the jobs that are likely to stay in demand. In the face of declining public health, each person should learn to take charge of his or her own health. Lastly, we must help foster local community networking, which will be essential in preserving basic services like public safety and sanitation when the federal government proves ineffectual.
Greer discusses at length the tools and technologies needed in order to bring about these changes. Many of these tools, he points out, could easily be salvaged from present-day technologies that are bound to fall into disuse as profligate energy use becomes prohibitively expensive. For example, alternators from automobile engines could be used to build waterwheel-based micro-hydro plants.
We could also profit greatly from revitalizing antique tools, such as wooden ships and fireless cookers, that are better suited to energy conservation, and less reliant on electronic gadgetry, than their modern-day counterparts are. Two other technologies that could serve us well in the deindustrial future are organic intensive farming and the farmers market movement (the latter being an example of a "social technology").
The final part of the book examines the spiritual dimension of the changes ahead. At the heart of our coming spiritual transformation, Greer believes, is a shift away from the "prosthetic society" in which machines perform an ever-increasing number of tasks that were once done by humans. As human labor once again becomes cheaper than machine labor, people will relearn a host of now-forgotten skills, and will abandon consumerism in favor of more spiritually fulfilling pursuits.
More fundamentally, people will lose faith in the religion of progress — and it is a religion, Greer convincingly argues — as it proves less and less capable of delivering on its promises. Greer makes a few educated guesses as to which religious faiths might prosper in its wake.
I can also easily imagine various other scenarios, without feeling much confidence in any of them! I have trouble imagining that we will return to traditional lifestyles from the agrarian past: I think we know more now, and not all this knowledge will be lost, and not all of it requires lots of energy to be useful. (Actually, after reading more of his stuff, it seems Greer agrees with me here.)
I also have trouble imagining that people will "abandon consumerism in favor of more spiritually fulfilling pursuits", attractive as that sounds. They may abandon consumerism because they can't afford it.
But we'll see. Or at least our descendants will see.
For more, try:
Fissionable uranium is well down its own depletion curve, and it's worth noting that the enthusiastic claims sometimes made for breeder reactors, the use of thorium as a nuclear fuel, and other alternatives to conventional fission plants are very rarely to be heard from people who have professional training in the fields concerned.If nuclear power is too dangerous, people will still use it. But if it runs out, that's a different matter.
Will it? Compare for example this quote from James Hansen's new book, Storms of My Grandchildren. Hansen thinks fast nuclear reactors, also known as "breeder" reactors, have a bright future:
Nuclear experts at the premier research laboratories have long realized that there is a solution to the waste problems, and the solution can be designed with some very attractive features.Hansen and Greer can't both be right.
I am referring to "fast" nuclear reactors. Fast reactors allow the neutrons to move at higher speed. The result in a fast nuclear reactor is that the reactions "burn" not only the uranium fuel but all of the transuranic actinides — which form the long-lived waste that causes us so much heartburn. Fast reactors can burn about 99 percent of the uranium that is mined, compared with the less than 1 percent extracted by light-water reactors.
The United States is presently storing about six hundred thousand tons of uranium hexafluoride, a by-product of nuclear weapons production. A reasonable assessment of the value of this material as fuel, if fast reactors were deployed as the energy source for power plants, is about $50 trillion. Yes, trillion. But it will take almost a thousand years to use all that fuel, so don't expect a customer to buy it all at once.
In fact, given that fast reactors make it economical to extract uranium from seawater, we now have enough fuel, in theory, to run nuclear power plants for several billion years. In other words, nuclear fuel is inexhaustible, putting it in the same category as renewable solar energy.
The hills are full of green plant life, mainly grass. It's been raining a lot lately! And indeed, it started to rain just as we got back to the car.
David Wohlert read my remark "I would love to read a careful analysis of declining civilizations" and pointed me to this book:
Like modern industrial society, the Maya built their civilization on a nonrenewable resource base. In their case it was the fertility of fragile tropical soils, which couldn't support intensive corn farming forever. On that shaky foundation they built an extraordinary civilization with fine art, architecture, astronomy, mathematics, and a calendar more accurate than the one we use today. None of that counted when the crops began to fail. Mayan civilization disintegrated, cities were abandoned to the jungle, and the population of the Mayan heartland dropped by 90%.Actually Diamond talks about the Maya, and I haven't read that chapter — I should. But apparently this book says more:
The parallels go deeper, for the Maya had other options. They could have switched from corn to more sustainable crops such as ramon nuts, or borrowed intensive wetland farming methods from their neighbors to the north. Neither of these happened, because corn farming was central to Maya political ideology. The power of the ahauob or "divine lords" who ruled Maya city-states depended on control of the corn crop, so switching crops or farming systems was unthinkable. Instead, Maya elites responded to crisis by launching wars to seize fields and corn from other city-states, making their decline and fall far more brutal than it had to be.
Even so, the Maya decline wasn't a fast process. Maya cities weren't abandoned overnight, as archeologists of two generations ago mistakenly thought, but went under in a "rolling collapse" spread across a century and a half from 750 to 900. Outside the Maya heartland, the process took even longer. Chichen Itza far to the north still flourished long after cities such as Tikal and Bonampak were overgrown ruins, and Mayan city-states on a small scale survived in corners of the Yucatan right up to the Spanish conquest.
Map the Maya collapse onto human lifespans and the real scale of the process comes through. A Maya woman born around 730 would have seen the crisis dawn, but the ahauob and their cities still flourished when she died of old age seventy years later. Her great-grandson, born around 800, grew up amid a disintegrating society, and the wars and crop failures of his time would have seemed ordinary to him. His great-granddaughter, born around 870, never knew anything but ruins sinking back into the jungle. When she and her family finally set out for a distant village, the last to leave their empty city, it would never have occurred to her that her quiet footsteps on a dirt path marked the end of a civilization.
I've been corresponding a bit with my former grad student Jeffrey Morton, who just got a postdoc position at the Universidade Technica de Lisboa. I told him I was getting interested in environmental stuff, and he wrote:
I'm also very interested in this subject, but so far I haven't had the impetus to try to address it professionally, as most of the mathematical aspects of that stuff I know anything about are all about modelling, dynamical systems, etc. which is not really my bag.I replied:
However, I will advocate to anyone who'll listen for moving off a terrestrial-resource economy to a solar-resource economy. Immediately, that means a transition to solar power, but more to the point, something to replace agriculture would be nice — we haven't had a fundamental revolution in food production in, what, ten thousand years? No wonder we're stressing ecosystem resources... And of course cities should be comprehensively recycling all their water.
Since the Obama administration is canning the human space-exploration program while also increasing NASA's budget, I'm hoping they'll be putting funds into developing space-based solar power. A square kilometre of thin-film solar cells could probably pack up into a single cargo with a good design, and it would produce on the order of a gigawatt of power with no further inputs. Launch costs are bound to start falling soon, and surely once a design exists, the unit production costs couldn't be too high — it's just that initial overhead that's the trouble.
Jeffrey wrote:He replied:I'm also very interested in this subject, but so far I haven't had the impetus to try to address it professionally, as most of the mathematical aspects of that stuff I know anything about are all about modelling, dynamical systems, etc. which is not really my bag.That's what a lot of smart mathematicians say, including me! So I figure it's my job to help change the situation, either by finding stuff for folks like us to do, or at least writing issues of This Week's Finds that get kids interested in doing stuff that can do some good — instead of getting them interested in octonions, n-categories etc.However, I will advocate to anyone who'll listen for moving off a terrestrial-resource economy to a solar-resource economy. Immediately, that means a transition to solar power, but more to the point, something to replace agriculture would be nice — we haven't had a fundamental revolution in food production in, what, ten thousand years?Suggestions for how the revolution should work?
This may not be practical, and maybe not revolutionary enough for you, but it's kinda cute:
- Lisa Chamberlain, Skyfarming, New York, April 1, 2007. (No joke.)And of course cities should be comprehensively recycling all their water.Here in Southern Ca. we're finally starting to get serious about catching runoff...Since the Obama administration is canning the human space-exploration program while also increasing NASA's budget, I'm hoping they'll be putting funds into developing space-based solar power. A square kilometre of thin-film solar cells could probably pack up into a single cargo with a good design, and it would produce on the order of a gigawatt of power with no further inputs. Launch costs are bound to start falling soon, and surely once a design exists, the unit production costs couldn't be too high — it's just that initial overhead that's the trouble.How practical is it getting the power down to the ground?
Suggestions for how the revolution should work?Those vertical farms would be a decent start — the technology basically exists. I would imagine this "revolution" happening at such a lightning fast pace that within a few centuries it might start to settle into some kind of established form once there's been time to test and find out what works best.
The first essential thing would be to get farms off of fertile land to allow room for more diverse, and possibly even natural, ecosystems to take over. See:
Beyond that, I see a few key areas for improvement, which I assume would happen incrementally, separately, and eventually be combined together.
- Land Commodities, Investment fundamentals.
I basically assume there would be a transition from growing plants, to some form of more or less direct chemosynthesis of food, if only for reasons of efficiency. (It's also not clear to me there isn't a reasonable ethical argument against using plants for food, as there is against using animals, but given that most people don't accept the latter, this is probably irrelevant — I'm not even vegan myself). Most likely some intermediate stage involving getting bacteria to produce the proteins, vitamins, etc. would be involved as well (as a bonus, I find it hard to get ethically worked up about exploiting bacteria when all you want them to do is replicate). Making sure the result is actually nutritious would be a big bioengineering challenge. Making it taste good is probably all too easy.
The first big inefficiency even in a sealed vertical farm: photosynthesis is fairly inefficient at capturing sunlight. Depending on conditions, it captures anything from <1% to around 5% of energy. Commercial photocells capture 20% and experimental ones up to 40%. A big Sterling engine and some mirrors can manage up to 30%. So there's about an order of magnitude in efficiency to play with there. I don't know all the engineering constraints, but clearly around two orders of magnitude is the most one can expect to get here.
However, the second thing is that in any given food crop, only about 10% of that captured energy actually gets converted into food energy usable by humans. Presumably some of that is a really irreducible requirement, and even a manufacturing "plant" would also need energy to operate it. But I would guess there's about a factor of about 5 to gain here.
Then there's the fact that a huge proportion of the plant-based foods that are produced, currently, are just fed to livestock that are used to produce meat, dairy, eggs, etc. Quite apart from ethical considerations, this is about another reduction of human-available food energy produced from a given solar energy budget by about a factor of 10. So by this stage, we've lost 99.9% to 99.99% of the original solar energy. So a reasonably conservative estimate would be that agriculture as a means to run humans off solar energy can be improved by probably a couple of orders of magnitude, depending on what assumptions you make about the originial eating habits. Not to mention the habitats freed up by decomissioning all that farmland.
Speaking of the practice of eating animal products, there's a nice graphic in here that pretty much sums up a big class of perverse incentives that prop up the industry:
- Good Medicine, Health vs. pork: Congress debates the farm bill.How practical is it getting the power down to the ground?Well, actually, I regard this as a good argument for not putting energy-intensive industry on the ground (at the bottom of a gravity well, in the middle of a biosphere, is probably a bad place for heavy industry anyway, a priori). But in any case, transmission could be an issue wherever you need to use the energy...
I understand there is some good work on microwave energy transmission. Actually, a little Wikipedia lookup suggests that my initial figure of a square-kilometer panel is probably below the threshold at which the marginal returns make sense. They suggest that a one-kilometer transmission rectifier-antenna combination in, say, geosynchronous orbit could focus a beam sufficiently to get a 10-kilometer footprint on the ground, and that a power density of about 20 milliwatts per cm2, for a total of about 10 gigawatts per installation, would be human-safe. (Especially if the microwaves are properly tuned not to dump too much energy into, for instance, water, which is desirable even apart from safety concerns). That implies a collector surface of about 10 km2, which is smaller than the antenna. I wonder if, safety aside, it would be practical to give the beam a higher power intensity than that from the ambient insolation. Anyway, putting the collector in space would presumably make it more reliable, less weather-dependent, and able to operate at night...
I have looked a little at some of the papers by Mitani and Shinohara et al. about this. They were describing actual experiments in power beaming that seem to work. This technology probably needs more R&D than the solar cells, though.
Now we can return to finishing off our invitation to higher gauge theory, a closely linked paper which, alas, is overdue! It's based on the notes of my Corfu talk last summer, but I want to expand them to a full-fledged course on higher gauge theory.
Lisa is taking off for China tomorrow night. So, today I decided to come with her to Temple City while she does tai chi in the park. We'll have dim sum and shop when she's done. Right now I'm taking a little break. I'm sitting here at the Roadhouse Coffee Stop. It's a friendly, homey place with free wireless. Cool and grey here, sunny back in Riverside.
A correspondent who is a bit of a "climate change skeptic" told me that "there's been no significant warming in the last 15 years" I asked him for evidence and he pointed me to this:
He draws a best-fit straight line through them: it slopes upwards at 0.95°C per century. Then he does a little statistical analysis of a standard sort. He assumes the difference between the line and the actual points is randomly distributed in a Gaussian way with zero mean. He works out the standard deviation of this Gaussian — and based on these assumptions, he concludes that there's an 86% chance that if you picked new points according to the same probability distribution, the line would still slope upwards.
Now, if the weather report said there was an 86% chance that it would get warmer tomorrow, you'd probably say "it's getting warmer". But this doesn't count as statistically significant according to standard practice. So, this guy rightly concludes it's only "somewhat more likely than not" that these points indicate a warming trend.
Here's my gut reaction to all this:
Satellites have only been measuring the temperature of the upper atmosphere over a short period of time. If we restrict our attention to satellite data, we're going to have a lot of trouble spotting long-term trends. For example, assuming the data is accurate, 1998 was an exceptionally hot year. It'll completely swamp any conclusions we draw from such a small data set. More importantly, any fluctuation will have a huge effect. The weather is just too noisy to draw any firm conclusions from little data.
Of course, this could be precisely what my correspondent was trying to say! But when you say "there's been no significant warming in the last 15 years," it sounds different than when you say "you can't draw firm conclusions from these particular 15 data points".
What if we use more data, over a longer time span? If we use the Goddard Institute for Space Science data taken from meteorological stations since 1880, we see this:
Now it really looks like the planet is warming up. On the other hand, my correspondent points out that some people have questioned data from the Goddard Institute:
For more on this issue, see:
It's got a lot of good graphs and discussion.
Robert Smart blogged about this diary entry.
March 14, 2010
I wrote a bunch about the Silk Road starting on November 19th and going on into December. Like many people, I'm fascinated
by that part of the world, which seems like the back of beyond from an
American point of view. But I just read about a history that takes
this part of the world as central:
I'd like to read it. You can see the introduction online.
Doing my taxes, I discovered that I spent 109 days away from home in 2009:
The longest trips were not the most tiring ones. Spending a long time in Paris was not tiring. The most tiring trip of all, at least in my memory, was the 5-day trip to Göttingen. I went with my student Chris Rogers. One leg of our flight was late so we wound up missing the next; we got into Frankfurt too late for the last train to Göttingen, so we had to spend a night in a hotel at the airport; then we caught an early train the next day.
I want to minimize short trips where I spend most of my time travelling. I've been doing a good job so far this year. Of course in July I'll be going to Singapore for a year! And I want to travel around there a bit — but luckily, there are lots of interesting places quite nearby. So, with luck I'll keep myself from getting overstretched and worn out.
Reading my last diary entry, you may wonder why I'm doing all this work on higher gauge theory and supersymmetric membranes. Didn't I say would switch to math that'll help the planet's ecosystem?
Doing research with five grad students is like being the engineer on a big powerful locomotive! It takes an enormous amount of time and effort to build up speed: at first there's a lot of huffing and puffing with almost imperceptible progress. But once the research gets rolling, it easily crashes through roadblocks that might stop a solo effort. When I get stuck on a project working on my own, I just switch to another one. But when I'm working with a grad student, it's harder to change direction: it's more efficient to just push ahead, if at all possible.
It's also hard to stop research when you're doing it with a team of grad students! You can't just leave them in the lurch. So, while I'm trying to stop working on n-categories and other forms of fancy mathematical physics, it's going to take a year or two. The breaks are squealing like mad, but right now we're still barrelling ahead.
After my students get their PhDs, I think I'll enjoy being a lighter, more maneuverable unit — at least for a while. It's probably not even wise to take on students in biomathematics, or climate modelling, or anything like that until I have a bit of a reputation. They'll want jobs, after all.
Without grad students, I could veer recklessly between quantum
computation, condensed mattter physics, biomathematics, climate change,
and pure math — working with James Dolan on the last of these, I hope.
That sounds fun. But as usual, unless I'm careful I'll probably get
too busy. I need to learn restraint.
March 15, 2010
I used Google's video service to remotely attend the oral exam of
Ross Tate, a computer
science grad student at U.C. San Diego who is interested in using
a certain generalization of monads to study "effects" in
functional programming. It took me forever to understand what computer
scientists mean by "effects" and
what these had to do with monads — even though monad
are a concept from category theory that I already knew and loved.
In a nutshell, the idea is this. The word "side-effect" probably comes closer to the right intuitive idea than the word "effect". When we write a program to do something, that program may have side-effects! The stuff we're really focusing on may interact with its environment. For example, when we think we are computing a function
X → Y
our program may mess around with the values of other variables in the memory, so a more complete treatment would treat it as a function
X × S → Y × S
Here X and Y are the input and output we're focusing on, while S is the "environment" — the stuff we might prefer to ignore. In computer science, people often rewrite the above function as a function
X → Y × hom(S,S)
where hom(S,S) is the set of all functions from the set S to itself. The operation of taking a set Y and forming its product with hom(S,S) has special properties, which make it a monad. And that's where monads get into the game. In fact this is just one example of an "effect" in computer science, and different effects correspond to different monads. This particular effect is called "state". Why? Well, the set S is the set of possible "states" of the environment.
But never mind the monad business. Here's another idea. Just focus on the function
X × S → Y × S
We see this sort of function whenever we're trying to study a dissipative system in classical mechanics! What we really have there is a system with some set of states X coupled to a "heat bath" with some set of states S. There's a deterministic time evolution rule
X × S → X × S
(Note that in this example Y = X, but we could do a more general once where it's not.) But we often try to ignore the heat bath, or think about it as little as possible. If we assume some probabilistic model of the state of the heat bath, then we get a nondeterministic time evolution rule
X → X
for the system we're really interested in. In other words, just like a sloppy programmer, we would like to ignore the "side-effects". But if we do so, we get punished in similar ways: nondeterminism, or even worse if our model of the state of the heat bath was wrong.
And here's another example: decoherence in quantum mechanics! Here when we try to ignore the system's coupling to the environment we are punished by having a perfectly deterministic unitary time evolution seem like a nondeterministic "collapse of the wave function".
So, these three problems — side-effects, dissipation, and decoherence — are all mathematically rather similar when you view them in terms of a general theory of systems and processes.
And here's a fourth example: "externalities" in economics, where we ignore side-effects like the pollution caused by burning coal. Again we're trying to ignore the environment, and again we get punished for this.
On a wholly other note: I want to learn more about Milankovich cycles as a cause of glacial periods, and why the amount of CO2 in the atmosphere seems to be highly correlated to the temperature, but seems to lag behind it. A couple of links, just so I don't forget them:
She's the youngest person to have done it! Three cheers!
Nathan Urban has some helpful comments on my March 13 and March 15 entries on climate change:
John,In case you forgot, the RealClimate links he was talking about are these:
A few comments on your recent diary entries:
1. Recent temperature trendsI pretty much agree with your gut reaction: there's an (ahem) significant difference between "there has been warming which is not statistically significant" and "global warming has stopped". Over a 15 year period it's hard for a trend to achieve statistical significance even if it's really there, given the amount of natural variability present. That's why "climatological periods" for trend analysis are often taken to be about 30 years, although that's somewhat ad-hoc and maybe you can get by with 20-25, I don't know. Of course, the more warming you expect, the quicker you expect it to achieve significance.
Actually, it's even harder to determine statistical significance of a short temperature trend than a simple regression analysis may indicate. Standard ordinary least squares (OLS) regression assumes that the error process is independent identically distributed normal. In reality, the residuals of a linear fit to a global temperature time series are not independently distributed: they are highly autocorrelated. If you take this into account using generalized least squares (GLS) regression, the confidence intervals get even wider because there are effectively fewer independent data points, and it takes and even stronger signal to rise to significance.
All this, by the way, assumes simple linear trend analysis with no covariate information. We don't expect the climate to be perfectly linear. A more sophisticated analysis would do multiple regression on covariates such as forcings. For example, where are we in the 11-year solar cycle, have there been any big volcanoes (no in the last 15 years), can we subtract out known random effects like the 1998 El Nino, etc. An even more sophisticated analysis would run these data through a climate model to see what temperature behavior is predicted — it's not going to be a perfect line. (Some people try to do this with the big IPCC climate models, the AOGCMs, but this is delicate for recent temperatures because they were mostly run using guesses for forcings past 2000, rather than the actual forcings.) Some people have looked at pieces of this type of analysis but I don't know if anyone has looked at all of them together.
2. Bias in the GISS dataIn general you should take any claims on Watts Up With That? with a very large grain of salt, because they have a history of posting ... questionable ... quantitative analysis.
Disclaimer: I'm no expert on temperature data products either.
However, in this case, they're correct: GISTEMP shows a greater recent warming trend than UAH. It's well known that UAH shows a lower warming trend, which is one reason why skeptics prefer it.
As a check, I quickly redid the analysis using the data in the link they provided.
(The analysis is just a few lines of code in the R statistical language, which is truly excellent for data analysis. If you're interested in playing around with data like this yourself, I could send you my R script.)
Using their data, I find that GISTEMP and UAH diverge since 2008 at a rate of 0.28 ± 0.08 °C/century, using OLS regression. This is slightly less than the 0.32 reported on Watts Up With That?, maybe because of an extra year of data since then, or data set revisions (both data sets are constantly tweaked). This divergence is statistically significant.
If I use GLS regression assuming AR(1) autocorrelation, I get a GISTEMP-UAH divergence of 0.27 ± 0.13 °C/century. This is also statistically significant, but only barely.
There is a key point being overlooked here. The Watts Up With That? post author would have you believe that if there is a divergence between GISTEMP and UAH, it's because GISTEMP is biased high. (He concludes that there are problems with both GISTEMP and the NOAA NCDC datasets.) However, the possibility remains that UAH is biased low.
What skeptics often don't mention is that just as there are multiple surface temperature data products (GISTEMP, NCDC, HADCRUT3), there are also multiple satellite temperature data products: UAH and RSS. The surface temperature products all ostensibly use pretty much the same data sources, but process them differently (e.g., bias adjustments). Likewise, the satellite products are based on the same satellites, but are processed differently, and make different adjustments. Notably, there was a change in satellites in 1992, and the UAH and RSS groups disagree in how to handle between-instrument calibration over that discontinuity.
For some reason many skeptics seem to latch onto the idea that the surface records are biased because of adjustments or station placement or whatever, but ignore the possibility that the satellite records could also be biased because of adjustments, errors in retrievals, etc.
It turns out that the RSS satellite record is much more similar to the surface station records, leaving UAH as the outlier. You can see this on the same "Wood for Trees" site where Watts Up With That? got the data:
This has GISTEMP, HADCRUT3, UAH, and RSS (omitting NCDC which isn't in their database). You can see that the HADCRUT3 and RSS trends are virtually indistinguishable, GISTEMP is slightly higher, and UAH is much lower. I have not calculated the divergence trends between these other time series and UAH but judging by the graph they should be similar to the GISTEMP-UAH trend.
In conclusion, it's rather hasty to assume that either GISTEMP or the surface temperature records in general are biased high. Whether they are or not requires a deeper analysis than that presented in the Watts Up With That? piece.
Glacial-interglacial temperature-CO2 relationshipI'm interested in this too but haven't found time to get too deeply into it yet.
In the meantime, here are some references off my reading list. I haven't checked to see if any of them are discussed in the links you gave. Some of these papers may supersede earlier papers on my list.
- On the nature of lead-lag relationships during glacial-interglacial climate transitions.
- Atmospheric CO2 and climate on millennial time scales during the last glacial period.
- Glacial greenhouse-gas fluctuations controlled by ocean circulation changes.
- Southern hemisphere and deep-sea warming led deglacial atmospheric CO2 rise and tropical warming.
- Timing of atmospheric CO2 and Antarctic temperature changes across Termination III.
- New constraints on the gas age-ice age difference along the EPICA ice cores, 0.50 kyr.
- What caused Earth's temperature variations during the last 800,000 years? Data-based evidence on radiative forcing and constraints on climate sensitivity.
- Glacial cycles and carbon dioxide: A conceptual model.
- Atmospheric CO2 concentrations over the last glacial termination.
- The 100,000-year ice-age cycle identified and found to lag temperature, carbon dioxide, and orbital eccentricity.
In addition to your RealClimate links, there are also some references here:
- Skeptical Science, CO2 lags temperature — what does it mean?
The names alone should cause anyone whose heart still beats to stop and look again. Blotched woodwax. Pashford pot beetle. Scarce black arches. Mallow skipper. Marsh dagger. Each is a locket in which hundreds of years of history and thousands of years of evolution have been packed. Here nature and culture intersect. All are species that have recently become extinct in England.He suggests giving more species plain English names so people can get to know them and maybe love them more than if they only have scientific names. How about saving their DNA while we're at it? Remember Betsy Dresser from my January 10th entry? Admittedly, baby cloned moths would not make so charismatic picture as baby cloned African wildcats. But maybe someday, as biotechnology gets cheaper, hobbyists will want to revive more and more extinct species? An alternative possibility is that they'll prefer to engineer new ones. Let us hope that while some biohackers create glow-in-the-dark monkeys, the height of good taste and refinement will be to recreate extinct species.
photo by Graham Wenman
I cannot claim that I've been materially damaged by their loss, any more than the razing of the Prado would deprive me of food or shelter. But the global collapse of biodiversity hurts almost beyond endurance. The sense that the world is greying, its wealth of colour and surprise and wonder fading, is so painful that I can scarcely bear to write about it. Human welfare, as measured by gross domestic product, is doubtless enhanced by the processes which drive extinction. Human welfare, as measured by the heart and the senses, is diminished. We have no use for most of the world's natural exuberance; it cannot be commodified or reproduced. Biodiversity does not belong to us: that is why it is worth preserving.
In Doha today, governments are engaged in their annual festival of frustration: the endless arguments over the Convention on International Trade in Endangered Species. They are struggling against what often looks like an inexorable assault by technology, economic growth and sheer bloody idiocy. The latter is exemplified by the battle over the Atlantic bluefin tuna. Many governments want to ban the trade in this species for several years, but Japan is resisting furiously. Whether or not a ban is imposed, the effect on Japanese industry will be roughly the same, as the species is likely to become commercially extinct next year if current fishing levels continue. But the government would prefer one more year of raw exploitation to indefinite supplies in the future. There is no reasoning with this madness.
But it's the new report by Natural England which hit me hardest. English plant and animal species are still disappearing at the rate of two a year. All the goodwill, the billions of pounds and millions of hours poured into conservation work, the global treaties and concordats seem to be no match for the amplification of our presence on earth. If we can't even get this right in England, where the two biggest membership organisations are both conservation groups, where does hope lie?
There were several shocks in the report, but it was a different set of names that hammered into my mind. Some of the most endangered species have very ordinary, even — if I might be so rude — common names. The common frog, common gull, common skate and common smoothhound are all in trouble. The common eel is now listed as critically endangered everywhere. I remember, years ago, sitting beside a chalkstream whose entire bed was a writhing black conveyor belt of eels moving upriver. The eel was a universal, indestructible species. It can live almost anywhere, even stagnant water in which no other fish can survive, it can eat any old carrion and travel overland between ponds on dewy nights. Nobody valued them because they were everywhere. Had someone told me, on the bank of that river, that within my lifetime they would be threatened with extinction, I would have laughed out loud. If the common eel is now critically endangered, is any species safe?
I got an email from Søren Jensen about the statistical analysis of temperature series data:
I just saw your entry for the 13th of March, and in that connection I would like to point you to this blog post:
Tamino, How long?, Open Mind, December 15, 2009.
where the question is examined in detail by a professional statistician. I have redone some of the graphs in Matlab, and can send my scripts to you if you want.
The analysis is done in a similar way here, by a guy from the skeptic side:
- Jeff Id, No warming for fifteen years?, The Air Vent, November 12, 2009.
By the way, Motl is in error when he assumes that the noise on the temperature data is white noise, as explained by Tamino.
Here is a link to a blog that examines controversial questions in climate science in good way:
Good luck with your journey into climate science,
Søren R. Jensen
If the Earth is warming, it's not the atmosphere we should be focused on. It's the oceans! Water has a high specific heat, so that's where most of the heat energy goes — and the short-scale temperature fluctuations, which I've been writing about above, are much smaller.
Tonight I had dinner
with Stephen Jordan,
a postdoc at the Institute
for Quantum Information who has some connection to the
through his friend Michael
Vassar. I want to examine radically different alternative views about the
near future for the new This Week's Finds, and interview
scientists about their work. For this, it would be great to talk to
Yudkowsky or someone....
March 20, 2010
There's been some new genetic research that suggests that dogs were
first domesticated in the Middle East:
Together with his colleagues from UCLA, Robert Wayne studied the DNA from over 200 wild gray wolves, found some markers of distinct populations, and looked for these in the DNA of 900 dogs from 85 different breeds. Most dogs shared markers with Middle Eastern wolves, though some dog breeds were related to different wolf populations. Previous papers had suggested that dogs came from east Asia. Quoting the UCLA website:
"This study is unique in using a particular technology called a single nucleotide polymorphism, or SNP, genotyping chip; these chips interrogate the nucleotides at 48,000 locations in the genome," said John Novembre, UCLA assistant professor of ecology and evolutionary biology and a member of UCLA's Interdepartmental Program in Bioinformatics. "We are able to compare dogs looking at not just one small part of the genome, but at 48,000 different locations. That gives us the fine-scale resolution to analyze how these breeds are related to one another and how they are related to wolves."
Previous genetic research had suggested an East Asian origin based on the higher diversity of mitochondrial sequences in East Asia and China than anywhere else in the world. (Mitochondria are tiny cellular structures outside the nucleus that produce energy and have their own small genome.) However, that research was based on only one sequence, a small part of the mitochondrial genome, Wayne noted.
"That research made extrapolations about how the domestic dog has evolved from examination of one region in the mitochondrial genome," Wayne said. "This new Nature paper is a much more comprehensive analysis because we have analyzed 48,000 markers distributed throughout the nuclear genome to try to conclude where the most likely ancestral population is.
"What we found is much more consistent with the archaeological record," he said. "We found strong kinship to Middle Eastern gray wolves and, to some extent, European gray wolves . but much less so to any wolves from East Asia. Our findings strongly contradict the conclusions based on earlier mitochondrial DNA sequence data."
Here is the chart that Wayne's team came up with:
I've written about the domestication of dogs earlier, in my September 28, 2007 and August 30, 2009 diary entries. But let me remind you of that stuff here, so you don't have to go doggedly clicking to read it all.
First of all, in 2007, Elaine Ostrander studied the DNA of lots of dogs and cats:
Dogs are now considered a subspecies of the gray wolf, which in turn is one of many closely related species of canids:
Ostrander argued that there are four general kinds of dogs, genetically speaking:
Another interesting question is when the domestication happened. Wolf remains have been found in association with hominid remains as far back as 400,000 years ago. The precise time at which some wolves became domesticated "dogs" will probably be argued forever. One has to wonder, what's the definition of when a "wolf" becomes a "dog"? Dogs can and still do interbreed with wolves and other canids, after all. Indeed, Robert Wayne has argued that this is why half of North American wolves are black.
One interesting possibility is that a canid counts as domestic when it will eat in the presence of humans.
Personally, not being at all expert on this subject, I suspect a much earlier date for domestication. It's easy for me to imagine wolves being domesticated as soon as hominids started using fire to cook meat. The use of fire dates back to around 1.4 million years ago, long before Homo neanderthalensis showed up.
Some Russian biologists did an interesting experiment that sheds some light on the process of domestication. They kept a colony of silver foxes and bred them to be less scared of people, less aggressive.
After just 10 generations, 18% of the foxes sought human contact and showed little fear! And after about 30 generations, a true "domesticated fox" had developed. At the end, the Russians had 700 domesticated foxes — but they ran out of money when the USSR collapsed, and had to sell 600 of them as pets. At last report, "Most of the project expenses are covered by selling the foxes as pets, but the project remains in a difficult situation, looking for new sources of revenue from outside funding".
Anyway: domestication can happen quickly under laboratory conditions, but that only sets a lower bound on how long it took for wolves to become dogs.
Anyway, this article summarizes our rather sketchy state of knowledge of when wolves were first domesticated:
Let me quote a bit:
Another way of estimating the time at which domestic dogs originated is to consider their genetic differences from wolves. One prominent group of researchers, including Robert Wayne, along with Carles Vilà of the Uppsala University in Sweden and their collaborators, initially estimated in 1997 that dogs diverged from gray wolves 100,000 to 135,000 years ago. After more study, they revised their divergence date to between 40,000 and 100,000 years ago. Another group, led by Peter Savolainen of the Royal Institute of Technology in Sweden, favored the Chinese wolf, a subspecies of the gray wolf, as the probable ancestor and estimated in 2002 that it was domesticated between 15,000 and 40,000 years ago.The article then describes Germonpré's research in more detail: studies of canine skulls from various Paleolithic sites in Europe, studies of mitochondrial DNA in ancient canine bones, and best of all, how this work led to the realization that a fossilized dog from Goyet Cave in Belgium was about 31,680 years old! This is about the time of the earliest cave paintings in Europe. For example, the Chauvet Cave in France has paintings about 32,900 ± 490 years old, and also the footprints of a human child, along with dog footprints that seem to be following her!
How do these genetic estimates stack up against the fossil record? Until 2009, the oldest known remains of domestic dogs were two adult skulls dated to between 13,000 and 17,000 years ago, from Eliseevichi, a region in Russia. Both had the relatively broad, short snout typical of dogs, and both were large, heavy animals, nearly the size of great Danes.
Then a team led by Mietje Germonpré of the Royal Belgian Institute of Natural Sciences reported a stunning new finding in the February 2009 issue of Journal of Archaeological Science: a nearly complete fossil dog skull dated to 31,680 ± 250 years ago.
Carbon dating of charcoal from "a torch the child carried" —
but how do they know that? — says it's about 26,000 years old.
March 21, 2010
hoist that rag
hoist that rag
well we stick our fingers
in the ground,
heave and turn
the world around
smoke is blacking
out the sun
at night I pray
and clean my gun
the cracked bell rings
as the ghost bird sings
and the gods go begging here
so just open fire
as you hit the shore
all is fair in love
hoist that rag
hoist that rag
hoist that rag
hoist that rag
A friend warned me against getting involved in the politics of global warming, urging me to stick to the science. I had trouble sorting this out at first. I think this remark from Eliezer Yudkowsky's essay Politics is the Mind-Killer helped me get the point:
Politics is an extension of war by other means. Arguments are soldiers. Once you know which side you're on, you must support all arguments of that side, and attack all arguments that appear to favor the enemy side; otherwise it's like stabbing your soldiers in the back — providing aid and comfort to the enemy.I think it's this mindset that I need to avoid. Gotta be careful: it creeps up on you!
For anyone who thinks that climate science must be unimpeachable to be useful, the past few months have been a depressing time. A large stash of e-mails from and to investigators at the Climatic Research Unit of the University of East Anglia provided more than enough evidence for concern about the way some climate science is done. That the picture they painted, when seen in the round — or as much of the round as the incomplete selection available allows — was not as alarming as the most damning quotes taken out of context is little comfort. They offered plenty of grounds for both shame and blame.And here's the end:
At about the same time, glaciologists pointed out that a statement concerning Himalayan glaciers in the most recent report of the Intergovernmental Panel on Climate Change (IPCC) was wrong. This led to the discovery of other poorly worded or poorly sourced claims made by the IPCC, which seeks to create a scientific consensus for the world's politicians, and to more general worries about the panel's partiality, transparency and leadership. Taken together, and buttressed by previous criticisms, these two revelations have raised levels of scepticism about the consensus on climate change to new heights.
Increased antsiness about action on climate change can also be traced to the recession, the unedifying spectacle of last December's climate-change summit in Copenhagen, the political realities of the American Senate and an abnormally cold winter in much of the northern hemisphere. The new doubts about the science, though, are clearly also a part of that story. Should they be?
In any complex scientific picture of the world there will be gaps, misperceptions and mistakes. Whether your impression is dominated by the whole or the holes will depend on your attitude to the project at hand. You might say that some see a jigsaw where others see a house of cards. Jigsaw types have in mind an overall picture and are open to bits being taken out, moved around or abandoned should they not fit. Those who see houses of cards think that if any piece is removed, the whole lot falls down. When it comes to climate, academic scientists are jigsaw types, dissenters from their view house-of-cards-ists.
The defenders of the consensus tend to stress the general consilience of their efforts.the way that data, theory and modelling back each other up. Doubters see this as a thoroughgoing version of "confirmation bias", the tendency people have to select the evidence that agrees with their original outlook. But although there is undoubtedly some degree of that (the errors in the IPCC, such as they are, all make the problem look worse, not better) there is still genuine power to the way different arguments and datasets in climate science tend to reinforce each other.
The doubters tend to focus on specific bits of empirical evidence, not on the whole picture. This is worthwhile — facts do need to be well grounded — but it can make the doubts seem more fundamental than they are. People often assume that data are simple, graspable and trustworthy, whereas theory is complex, recondite and slippery, and so give the former priority. In the case of climate change, as in much of science, the reverse is at least as fair a picture. Data are vexatious; theory is quite straightforward. Constructing a set of data that tells you about the temperature of the Earth over time is much harder than putting together the basic theoretical story of how the temperature should be changing, given what else is known about the universe in general.
Adding the uncertainties about sensitivity to uncertainties about how much greenhouse gas will be emitted, the IPCC expects the temperature to have increased by 1.1ºC to 6.4ºC over the course of the 21st century. That low figure would sit fairly well with the sort of picture that doubters think science is ignoring or covering up. In this account, the climate has natural fluctuations larger in scale and longer in duration (such as that of the medieval warm period) than climate science normally allows, and the Earth's recent warming is caused mostly by such a fluctuation, the effects of which have been exaggerated by a contaminated surface-temperature record. Greenhouse warming has been comparatively minor, this argument would continue, because the Earth's sensitivity to increased levels of carbon dioxide is lower than that seen in models, which have an inbuilt bias towards high sensitivities. As a result subsequent warming, even if emissions continue full bore, will be muted too.The political battle is heating up, as can be seen from this editorial in Nature. I present it here because it illustrates the mood, and because you'd otherwise need a subscription to read it! It's pathetic that Nature is talking about such important and controversial issues behind the wall of "for subscribers only".
It seems unlikely that the errors, misprisions and sloppiness in a number of different types of climate science might all favour such a minimised effect. That said, the doubters tend to assume that climate scientists are not acting in good faith, and so are happy to believe exactly that. Climategate and the IPCC's problems have reinforced this position.
Using the IPCC's assessment of probabilities, the sensitivity to a doubling of carbon dioxide of less than 1.5ºC in such a scenario has perhaps one chance in ten of being correct. But if the IPCC were underestimating things by a factor of five or so, that would still leave only a 50:50 chance of such a desirable outcome. The fact that the uncertainties allow you to construct a relatively benign future does not allow you to ignore futures in which climate change is large, and in some of which it is very dangerous indeed. The doubters are right that uncertainties are rife in climate science. They are wrong when they present that as a reason for inaction.
Climate of Fear
The integrity of climate research has taken a very public battering in recent months. Scientists must now emphasize the science, while acknowledging that they are in a street fight.
Climate scientists are on the defensive, knocked off balance by a re-energized community of global-warming deniers who, by dominating the media agenda, are sowing doubts about the fundamental science. Most researchers find themselves completely out of their league in this kind of battle because it's only superficially about the science. The real goal is to stoke the angry fires of talk radio, cable news, the blogosphere and the like, all of which feed off of contrarian story lines and seldom make the time to assess facts and weigh evidence. Civility, honesty, fact and perspective are irrelevant.
Worse, the onslaught seems to be working: some polls in the United States and abroad suggest that it is eroding public confidence in climate science at a time when the fundamental understanding of the climate system, although far from complete, is stronger than ever. Ecologist Paul Ehrlich at Stanford University in California says that his climate colleagues are at a loss about how to counter the attacks. "Everyone is scared shitless, but they don't know what to do," he says.
Researchers should not despair. For all the public's confusion about climate science, polls consistently show that people trust scientists more than almost anybody else to give honest advice. Yes, scientists' reputations have taken a hit thanks to headlines about the leaked climate e-mails at the University of East Anglia (UEA), UK, and an acknowledged mistake about the retreat of Himalayan glaciers in a recent report from the Intergovernmental Panel on Climate Change (IPCC). But these wounds are not necessarily fatal.
To make sure they are not, scientists must acknowledge that they are in a street fight, and that their relationship with the media really matters. Anything strategic that can be done on that front would be useful, be it media training for scientists or building links with credible public-relations firms. In this light, there are lessons to be learned from the current spate of controversies. For example, the IPCC error was originally caught by scientists, not sceptics. Had it been promptly corrected and openly explained to the media, in full context with the underlying science, the story would have lasted days, not weeks. The IPCC must establish a formal process for rapidly investigating and, when necessary, correcting such errors.
The unguarded exchanges in the UEA e-mails speak for themselves. Although the scientific process seems to have worked as it should have in the end, the e-mails do raise concerns about scientific behaviour and must be fully investigated. Public trust in scientists is based not just on their competence, but also on their perceived objectivity and openness. Researchers would be wise to remember this at all times, even when casually e-mailing colleagues.
US scientists recently learned this lesson yet again when a private e-mail discussion between leading climate researchers on how to deal with sceptics went live on conservative websites, leading to charges that the scientific elite was conspiring to silence climate sceptics (see page 149). The discussion was spurred by a report last month from Senator James Inhofe (Republican, Oklahoma), the leading climate sceptic in the US Congress, who labelled several respected climate scientists as potential criminals — nonsense that was hardly a surprise considering the source. Some scientists have responded by calling for a unified public rebuttal to Inhofe, and they have a point. As a member of the minority party, Inhofe is powerless for now, but that may one day change. In the meantime, Inhofe's report is only as effective as the attention it receives, which is why scientists need to be careful about how they engage such critics.
The core science supporting anthropogenic global warming has not changed. This needs to be stated again and again, in as many contexts as possible. Scientists must not be so naive as to assume that the data speak for themselves. Nor should governments. Scientific agencies in the United States, Europe and beyond have been oddly silent over the recent controversies. In testimony on Capitol Hill last month, the head of the US Environmental Protection Agency, Lisa Jackson, offered at best a weak defence of the science while seeming to distance her agency's deliberations from a tarnished IPCC. Officials of her stature should be ready to defend scientists where necessary, and at all times give a credible explanation of the science.
These challenges are not new, and they won't go away any time soon. Even before the present controversies, climate legislation had hit a wall in the US Senate, where the poorly informed public debate often leaves one wondering whether science has any role at all. The IPCC's fourth assessment report had huge influence leading up to the climate conference in Copenhagen last year, but it was always clear that policy-makers were reluctant to commit to serious reductions in greenhouse-gas emissions. Scientists can't do much about that, but they can and must continue to inform policy-makers about the underlying science and the potential consequences of policy decisions — while making sure they are not bested in the court of public opinion.
But an old xeroxed typewritten manuscript by Yvonne Choquet-Bruhat, on the existence of global solutions for the Yang-Mills equations, brings back the bygone age when I was struggling to find my feet after grad school, working on nonlinear partial differential equations, not really sure what I wanted to do. It reminds me of hearing her give a talk about this subject at MIT: a short elderly woman with a very strong French accent, one of Irving Segal's few mathematical friends at that time, standing in front of a blackboard, explaining the estimates necessar to prove global existence of solutions of the Yang-Mills equations with sufficiently small initial data.
Out with it — I don't really need it, and I'm sure the published version is available online. But it was good to be reminded of that scene.
Others seem too precious to throw out. An enormous xeroxed copy of Grothendieck's Pursuing Stacks. A nicely bound copy of Martin Neuchl's thesis. Some old reprints by Peter May. My handwritten notes from a graduate course on symplectic geometry, taught by Victor Guillemin. I don't think I need these, but they are irreplaceable — in some sense — and they have a lot of emotional significance.
There are even some lost treasures: Todd Trimble's notes on the Lie operad, for example! People have been seeking these for years. I scanned them in and put them on my Trimble webpage. Unfortunately my printed copy was missing page 16.
March 27, 2010
My sister Alex has been visiting — that's short for Alexandra.
On Tuesday she made it from Dulles to Denver, where her next
flight was cancelled due to a snowstorm — 9 inches of the stuff!
So, she had to spend a night on the airport floor. On
Wednesday morning she called me at 7. They put her on a flight to
Los Angeles instead of Ontario (the airport nearer to Riverside).
I roused myself and drove down there to catch her by 9:30. I was
just a bit late, but her flight was later: they delayed it until 10:23.
When she showed up, her luggage had been misplaced. We took advantage
of our misfortune by wandering around Playa Vista, a beach near the
LA airport. Thursday we went to Palm Canyon with Simon Willerton;
upon our return they'd delivered her luggage. On Friday we all
went to Joshua Tree. Today I handed her off to my aunt in Pasadena.
Now back alone... I should prepare my Rosetta Stone talk for Cal State Fresno, and polish up what John Huerta has written about the octonions — we're doing an article for Scientific American. As usual, I can think of all sorts of equally fun things to do, and I feel like doing them first. But I'll resist... as soon as I'm done with this diary entry.
Mike Stay points out this blog entry:
Carbon stays in the atmosphere for a long time.Read more on his blog or his Edge essay.
To many readers, this is nothing new, yet most who know this make a simple mistake [see below]. They think of carbon as if it were sulfur, with pollution levels that rise and fall with the rate of emission: Cap sulfur emissions, and pollution levels stabilize; cut emissions in half, cut the problem in half. But carbon is different. It stays aloft for about a century, practically forever. It accumulates. Cap the rate of emissions, and the levels keep rising; cut emissions in half, and levels will still keep rising. Even deep cuts won't reduce the problem, but only the rate of growth of the problem.
In the bland words of the Intergovernmental Panel on Climate Change, "only in the case of essentially complete elimination of emissions can the atmospheric concentration of CO2 ultimately be stabilised at a constant [far higher!] level". This heroic feat would require new technologies and the replacement of today's installed infrastructure for power generation, transportation, and manufacturing. This seems impossible. In the real world, Asia is industrializing, most new power plants burn coal, and emissions are accelerating, increasing the rate of increase of the problem.
In fact, the mistaken idea that CO2 behaves like a typical pollutant seems deeply entrenched in people's thinking (if you find it in your thinking, please make an effort to dig it out). I was disturbed to read a recent article in Science:
- John Sterman, Risk communication on climate: mental models and mass balance, Science, 24 October 2008, 532-533.
in which John Sterman describes a study in which a group of MIT students (from my own school!) flubbed this completely. After reading a description excerpted from the IPCC's Summary for Policymakers, they still misunderstood the problem, mistakenly thinking that limiting emissions would limit CO2 levels. From the Science article, with emphasis added:
The dynamics are easily understood using a bathtub analogy in which the water level represents the stock of atmospheric CO2. Like any stock, atmospheric CO2 rises when the inflow to the tub (emissions) exceeds the outflow (net removal), is unchanging when inflow equals outflow, and falls when outflow exceeds inflow. Participants were informed that anthropogenic CO2 emissions are now roughly double net removal, so the tub is filling.
Yet, 84% drew patterns [graphs of emission control policies and their effects] that violated the principles of accumulation.. Nearly two-thirds of the participants asserted that atmospheric GHGs [greenhouse gases] can stabilize even though emissions continuously exceed removal — analogous to arguing a bathtub continuously filled faster than it drains will never overflow. Most believe that stopping the growth of emissions stops the growth of GHG concentrations. The erroneous belief that stabilizing emissions would quickly stabilize the climate supports wait-and-see policies but violates basic laws of physics.
Training in science does not prevent these errors. Three-fifths of the participants have degrees in science, technology, engineering, or mathematics (STEM); most others were trained in economics. Over 30% hold a prior graduate degree, 70% of these in STEM. These individuals are demographically similar to influential leaders in business, government, and the media, though with more STEM training than most.
The way to remove CO2 quickly is to pump it, but this is a project too large to undertake with today's manufacturing infrastructure. However, as I note in the Edge essay,If we were good at making things, we could make efficient devices able to collect, compress, and store carbon dioxide from the atmosphere, and we could make solar arrays large enough to generate enough power to do this on a scale that matters. A solar array area, that if aggregated, would fit in a corner of Texas, could generate 3 terawatts. In the course of 10 years, 3 terawatts would provide enough energy remove all the excess carbon the human race has added to the atmosphere since the Industrial Revolution began. So far as carbon emissions are concerned, this would fix the problem.
I watched Heat Lightning last night, and also The Big Heat, a real classic film noir by Fritz Lang. You see, Turner Classic Movies was doing a special day of movies with "heat" in the title.
As if this weren't enough, I recently finished reading Raymond Chandler's first novel, The Big Sleep. As you may know, the the great Bogart-Bacall movie based on this novel was almost impossible to follow, since they cut a lot of crucial connecting scenes and also a long conversation between Marlowe and the Los Angeles District Attorney where the facts are explained. They've recently released a version that restores these scenes. But I haven't made up my mind whether this enhances or diminishes its curious charm! The film critic Bosley Crowther complained about the movie when it came out in 1946:
The Big Sleep is one of those pictures in which so many cryptic things occur amid so much involved and devious plotting that the mind becomes utterly confused. And, to make it more aggravating, the brilliant detective in the case is continuously making shrewd deductions which he stubbornly keeps to himself. What with two interlocking mysteries and a great many characters involved, the complex of blackmail and murder soon becomes a web of utter bafflement. Unfortunately, the cunning script-writers have done little to clear it at the end.But he also said that Bacall "still hasn't learned to act" — so what does he know? Personally I think the complex, baffling plot is part of what makes me willing to watch it over and over. That, and of course the incredible chemistry between Bogart and Bacall, and lots of great acting all around.
Anyway, reading the book does not completely dispel the mystery of the film, since the plot of the film diverges from that of the book in several points. For example: why does Vivian Sternwood go to that car garage in Realito? That's not in the book!
I want to read more by Raymond Chandler.
March 29, 2010
Sometime this summer, starting with "week301", I'm going to
drastically overhaul my column This Week's Finds.
Among other things, I'm thinking of doing some interviews, perhaps by email.
The idea would be to illustrate how smart
people are solving problems and dreaming up cool new ideas... so younger
people, or established academics who want to do something a bit more
useful, can see some role models. And
my hope is to pitch these interviews at a pretty high level, not
the usual journalistic watered-down crud. Just as a kind of self-reminder,
here's a little list of some people I might want to interview:
In compiling this list, I see that Stewart Brand has come out with a new book:
As for footprint, Gwyneth Cravens points out that "A nuclear plant producing 1,000 megawatts takes up a third of a square mile. A wind farm would have to cover over 200 square miles to obtain the same result, and a solar array over 50 square miles". That.s just the landscape footprint. (By the way, 1,000 megawatts equals 1 gigawatt — a billion watts; I'll use that measure most of the time here.)Watch this movie:
More interesting to me is the hazard comparison between coal waste and nuclear waste. Nuclear waste is minuscule in size — one Coke can's worth per person-lifetime of electricity if it was all nuclear, Rip Anderson likes to point out. Coal waste is massive — 68 tons of solid stuff and 77 tons of carbon dioxide per person-lifetime of strictly coal electricity. The nuclear waste goes into dry cask storage, where it is kept in a small area, locally controlled and monitored. You always know exactly what it's doing. A 1-gigawatt nuclear plant converts 20 tons of fuel a year into 20 tons of waste, which is so dense it fills just two dry-storage casks, each one a cylinder 18 feet high, 10 feet in diameter.
By contrast, a 1-gigawatt coal plant burns 3 million tons of fuel a year and produces 7 million tons of CO2, all of which immediately goes into everyone's atmosphere, where no one can control it, and no one knows what it's really up to. That's not counting the fly ash and flue gases from coal — the world's largest source of released radioactivity, full of heavy metals, including lead, arsenic, and most of the neurotoxic mercury that has so suffused the food chain that pregnant women are advised not to eat wild fish and shellfish. The air pollution from coal burning is estimated to cause 30,000 deaths a year from lung disease in the United States, and 350,000 a year in China.
© 2010 John Baez