Category: Science

New discoveries, the scientific method, and all matters relating to the scientific study of the physical world

Bill Gates on nuclear power

Bill Gates has brushed up against climate issues before. First, he apparently considered investing in the oil sands. Later, he invested $4.5 million of his own money in geoengineering research.

Most recently, he gave a talk at the TED conference advocating that developed countries and China cut greenhouse gas emissions to zero by 2050 (producing an 80% overall reduction), and do so largely on the basis of nuclear power. He thinks fast breeder reactors capable of using U-238 are the way forward, given how much more fuel would be available. His favoured version of breeder reactor is the traveling wave reactor, which is theoretically capable of using little or no enriched uranium.

Emissions equation

Gates argues that the key equation is: (population) X (services) X (energy use for services) X (greenhouse gas intensity of energy). To get down to zero, one of these elements needs to be reduced to that level. He argues that more services are important, especially for the world’s poor. Efficiency, he argues, can be improved quite substantially – perhaps increased three to sixfold, overall. The real work, he argues, needs to be done by cutting the GHG emissions associated with energy production to near zero.

Energy options

Gates argues that the energy systems of the future will need massive scale and high reliability. He singles out five he sees as especially promising, though with significant challenges:

  • Carbon capture and storage (CCS) – hampered by cost, access to suitable sites for injection, and long-term stability of stored gases (the toughest part)
  • Nuclear – with its cost, safety, proliferation, and waste issues
  • Wind
  • Solar photovoltaic
  • Solar thermal – all three limited by land use, cost, transmission requirements, and the need for energy storage to modulate fluctuations in output

Four others he describes as potentially able to make a contribution but decidedly secondary in importance:

  • Tide
  • Geothermal
  • Biomass
  • Fusion

I agree that fusion is a long shot that we cannot count on. I am more optimistic than Gates about the other three. Pumped tidal power could provide some of the energy storage he sees as so important. Enhanced geothermal looks like it has a lot of promise. Finally, combined with CCS, burning biomass offers us a mechanism to actually draw carbon dioxide out of the atmosphere and bury it.

The big picture

Cutting from the world’s current global emissions of about 26 billion tonnes (gigatonnes) of CO2 down to zero will require enormous activity. Quite possibly, nuclear will need to be part of that, despite its many flaws. That said, we need to be hedging all of our bets. One big accident could put people off nuclear, or fast breeder designs could continue to prove impractical. We need to be deploying options like huge concentrating solar farms in deserts and massive wind installations at the same time.

It is also worth noting that Gates’ assumptions about the rate at which emissions must be reduced are more lenient than those like James Hansen who are more concerned about when massive positive feedbacks will be kicked off. If the people who say we need to stabilize at 350 ppm are correct, Gates’ prescription of a 20% cut by 2020 and an 80% cut by 2050 will be inadequate to prevent catastrophic or runaway climate change.

Gates talks about this a bit during the questions. There are two risks: that his assumptions about the speed with which emissions must be cut are too lenient, or that his beliefs about the pace of technological development and deployment are overly optimistic. He thinks geoengineering could “buy us twenty or thirty years to get our act together.” Here’s hoping we never have to test whether that view is accurate.

Arctic sea ice volume

I expected Alun Anderson’s After the Ice: Life, Death, and Geopolitics in the New Arctic to mostly contain information I had seen elsewhere. In fact, it is chock full of novel and interesting details on everything from marine food webs to international law to oil field development plans. I read the first 200 pages in one sitting.

One chapter goes to some length in describing how we know what we do about Arctic sea ice volume. It is harder to measure than the extent of sea ice, which can be observed in all sorts of ways by satellites (optical instruments, synthetic aperture RADAR, passive microwave emissions, etc). One effort to estimate how ice volume is changing was based on multibeam SONAR on submarines. An 11 day survey conducted by Peter Wadhams, using the nuclear-powered HMS Tireless concluded that 40% of Arctic sea ice has been lost since the 1970s. Another team, led by Drew Rothrock, used previously secret US submarine data to confirm that figure for all areas that submarines have been visiting.

Anderson also describes the importance of the cold halocline layer: a thin layer of cold water that insulates the bottom of Arctic ice from the warmer Atlantic waters underneath. Without this layer, multiyear Arctic ice would be doomed. For a number of reasons, climate change threatens to undermine it. If it does, the complete disappearance of summer sea ice could occur faster than anyone now expects.

There are many reasons to worry about the vanishing Arctic ice, from the increased absorption of solar radiation that accompanies lost albedo to the danger of invasive species entering the Atlantic from the Pacific. I’ve written previously about ‘rotten’ ice, and many other issues in Arctic science.

Those much-hyped ‘Bloom Boxes’

Now that some figures are on their website, it is possible to comment a bit more meaningfully on Bloom Energy (beyond noting that they can attract a lot of heavyweights to their press events).

They seem to have deployed 3 megawatts of fuel cells in seven installations. That’s twice as much power as is provided by Grouse Mountain’s solitary wind turbine. Of these, two installations (with an output of 900 kW) are running on methane from renewable sources. According to Wikipedia, the fuel cells cost $7,000 to $8,000 per kilowatt. That is extremely high. An open cycle gas turbine power plant costs about $398 per kilowatt. Wind turbines cost something like $1,000 per kilowatt. Nuclear is probably over $2,000 and even solar photovoltaic is cheaper than $5,000. From an economic perspective, natural gas also isn’t the most appealing fuel for electricity production. It has significantly higher price volatility than coal.

Without more statistics, it is impossible to know how the efficiency of these fuel cells compares to conventional natural gas power plants, either before or after transmission losses are factored in. Bloom’s literature says that, when they are using conventional natural gas, emissions from their fuel cells are 60% lower than those from a coal power plant. Frankly, that isn’t terribly impressive. Coal plants generate massive amounts of CO2, relative to their power output. It also isn’t clear whether methane from renewable sources would be more efficiently used in these distributed fuel cells than in larger facilities based around turbines and combustion.

Many environmentalists assume that distributed power is the future, but there are definitely advantages to large centralized facilities. They can take advantage of economies of scale and concentrated expertise. They may also find it easier to maintain the temperature differential that establishes carnot efficiency.

It will be interesting to see how Bloom’s products stack up, when more comparative data is available.

Best books of 2009

Back in 2007, I put up a post listing my five favourite books of the year. Somehow, I missed 2008. Despite that, I am still happy to assert that the 2007 list includes some of the best books I have ever read.

Among the books I read in 2009, these are the five I most emphatically recommend:

It was a tough choice.

Margaret Atwood’s The Year of the Flood would be a natural successor to Oryx and Crake back in 2008. Unfortunately, the better book of the two remains the original.

If I had read Jared Diamond’s Collapse: How Societies Choose to Fail or Succeed soon after it had come out, it might have been one of my choices. That said, it is a compelling and important book.

Richard Dawkins’ The Greatest Show on Earth: The Evidence for Evolution certainly deserves a nod. For anyone who wants a comprehensible account of why we know as much about evolution as we do, this is the book to read.

You can read all my book reviews here.

I may eventually cook up a retroactive 2008 list.

Past lives of climate deniers

My friend Antonia sent me a nice article by Jeffrey Sachs, describing what today’s most prominent climate change deniers were doing, before they took up this cause:

Today’s campaigners against action on climate change are in many cases backed by the same lobbies, individuals, and organisations that sided with the tobacco industry to discredit the science linking smoking and lung cancer. Later, they fought the scientific evidence that sulphur oxides from coal-fired power plants were causing “acid rain.” Then, when it was discovered that certain chemicals called chlorofluorocarbons (CFCs) were causing the depletion of ozone in the atmosphere, the same groups launched a nasty campaign to discredit that science, too.

Later still, the group defended the tobacco giants against charges that second-hand smoke causes cancer and other diseases. And then, starting mainly in the 1980s, this same group took on the battle against climate change.

What this reinforces is how artificial the climate change denial movement is. Status quo actors, from Duke Energy to Saudi Arabia to Canada’s oil-sands-funded politicians, want to avoid climate change legislation. They have found some shills happy to spread confusion, in order to advance that aim. What is sad is how many ordinary people have lined up to be duped.

Evaluating existing climate change information

This may strike some people as abstract, but perhaps it will be of interest to someone.

Assume, to start with, that climate change is a major threat to humanity and that concerted global effort is required to deal with it. In that case, I see two possibilities:

  1. If all of humanity and all human knowledge were put in an abstract place together and given all the time they needed to educate one another, consider the data, and deliberate, they would come to a conclusion that strong climate change mitigation action ought to be undertaken.
  2. Even with all our current information and unlimited time, this conclusion could not be widely endorsed. It may, however, be the case that the people in this abstract space would reach the conclusion that we must act, if only they had some new information that we have not yet observed or collected.

Part of the answer involves the depths of human ideological and theological beliefs. If there are people who can never be shaken in their belief that the world is benevolent and concerned about humans, they could never be convinced otherwise by education or information. Part of the answer may have to do with the overall relationship in human beings between perceived risks and the willingness to take precautionary action. That said, I am convinced that an impartial assessment of climate science and the situation we are in would lead most any rational human being to endorse a precautionary approach.

I am similarly convinced that people in my ideal case would eventually overwhelmingly support aggressive mitigation actions. I don’t think human beings would be happy to expose all future generations to the risk of misery and possible extermination, just so they can avoid a transition to renewable energy that would be necessary regardless of climate change, and which can probably be accomplished for a few percent of GDP, spread over many years.

Of course, the real world is very different from my little imagined experiment. Time is important here. If climate change deniers can keep the public confused for another 20 years, that will have a huge impact, even if they could eventually have been unmasked as self-interested charlatans in my infinite-time case. Time can also work to our advantage, however. Striking new information can come to light and, in so doing, it can have an effect on what beliefs and priorities people hold faster than old information would be able to do in an education-and-discourse manner. For example, if we were to observe a drought of unprecedented scale and severity, it might have a big impact on the willingness of people to endorse the kind of high-level policies and actions necessary to curb the harmful influence of human beings on climate (or perhaps not).

What do you think? Would people reach a consensus in favour of strong mitigation action, given all the information and infinite time? If not, what further information might they require? In either case, what is the effect of the differences between my ideal infinite-time case and the real world, in which our choices in the next couple of decades will do much to determine where the climate ends up?

Xyloexplosive devices

The funniest videos to watch backwards are those in which entropy increases a lot: things like explosions and toppling dominoes, where it is completely obvious that the order of the video frames has been reversed. By contrast, something like a bouncing ball is pretty boring to watch backwards.

Tom Stoppard’s play Arcadia features some good discussion of entropy, and reactions that cannot be reversed. It is easy enough to stir jam into pudding, but impossible to unstir it back out. In addition to showing us something about the nature of time in our universe, it is a decent metaphor for why human regret can be counterproductive. You can’t unstir the pudding, after all.

Enterprising geeks have cooked up an entertaining new way to rapidly increase the entropy of a bunch of popsicle sticks or tongue depressors. It’s like a more energetic version of dominoes, and well worth a look both forwards and backwards.

Seeking certainty about climate change

I have written before about the problem of what can and cannot be known about climate change, given that we only have one planet to experiment on, and our simulations will never be accurate beyond question. Here is another expression of the same basic idea. I am trying to figure out the most effective way to convey this information to people who don’t think we should be taking aggressive action on climate change.

This chart shows four possible situations that humanity could find itself in, 100 years or so from now. Either climate change has been disastrous or it has not been, and we either took strong action to deal with it or we did not:

As you can see, there is only one situation in which we can be absolutely sure we made the right choice. Even that is a bit ambiguous, though. Imagine the decision isn’t about climate change but about Russian Roulette. If we are alive after the game, but we did choose to play, can we really be said to have behaved prudently? The sheer fact that the chamber didn’t turn out to be loaded doesn’t mean that we were intelligent to run the risk, back when we didn’t know that for sure.

Imagine two snakes, both of which look very similar. One is deadly venemous, and the other is benign. If the best information we have at hand suggests that there is a good chance we are dealing with the venemous one (say, because we are in the region where it usually lives), the prudent thing is certainly to behave as though the snake may be venemous. Even if you learn later that it was not, nobody will think you were a fool for acting that way. The climate science we have now is providing good reasons to think that we are dealing with a deadly snake of a problem.

In short, the science will never be settled in the sense that it will tell us exactly what to do. All it can do is become clear enough to make the prudent choice obvious to most people.

Degrees of frost

For practicality, you can’t beat the Celsius temperature scale. Were it not for the stubbornness of Americans, the weird Fahrenheit alternative (initially established with ice, brine, and an armpit) would be long-gone. For scientists, the Kelvin scale lets you represent temperature appropriately for thermodynamic calculations, and helpfully retains the same unit size as Celsius.

I would have thought the case would be closed there, but Bill Streever’s book made me aware of a more romantic-sounding alternative: degrees of frost. This temperature measure – a favourite of penguin-egg-gatherer and Antarctic explorer Apsley Cherry-Garrard – measures how many degrees it is below the freezing temperature of water.

Naturally, I prefer the Celsius version, though it sounds a bit less dramatic. Right now, it is a completely tolerable -4˚C in Ottawa. That’s just four degrees of frost – nothing to compared to the 60.8 degrees of frost experienced by Cherry-Garrard. The worst I’ve seen in Ottawa is about thirty degrees of frost, during my first frozen winter in Ottawa. Wind chill, incidentally, is not really a very scientific thing.

China and other developing states

Leaked Chinese documents claim that Canada and other developed nations have “connived” in a “conspiracy to divide the developing world.” It’s not surprising that China wants to be treated in the same way as extremely poor developing states, from whom no costly action is expected. At the same time, we just cannot afford to treat China and India like Mali or Guinea. The kind of climate future generations will live in is being affected strongly by choices made in Beijing and Delhi. That needs to be recognized – as does the need for India and China to accept emissions curbs.

This isn’t to say that India and China don’t have any claim to special treatment. Their per-capita and historical emissions are both low. That being said, the special treatment they receive cannot take a form that allows them to pursue the sort of high-carbon development track they have been. Unfair as it may be, they are going to need to develop primarily on the basis of low- and zero-carbon forms of energy (at the same time as developed states are aggressively cutting back on fossil fuel use) or we will get into a situation where it becomes very difficult to imagine how catastrophic climate change could not occur.

The great majority of the world’s emissions come from a dozen or so countries. Getting them on track towards carbon-neutrality is essential. That isn’t the case when it comes to small and very poor states who can be brought in line later without serious consequences. There is no need to be conspiratorial about it, but China and India really must be divided from the rest of the developing world.