The environment – Page 164 – a sibilant intake of breath

Chernobyl gets a new hat

At the same time as enthusiasm is growing for the use of nuclear fission as a non-greenhouse gas emitting energy source, the crumbling concrete tomb around the Chernobyl reactor is to be encased in steel, at an approximate cost of $1.4 billion. The doomed reactor will be covered by “a giant arch-shaped structure out of steel, 190 metres (623 feet) wide and 200m long.” Of course, it is only a matter of time before the new carapace will need to be replaced, in turn.

The Chernobyl disaster occurred back in 1986. Despite causing widespread contamination, about 95% of the radioactive material initially present remains within the site of the reactor complex. A motorcycle-riding photographer named Elena has put some haunting photos of the abandoned area on her website.

Just yesterday, Dr. Patrick Moore (co-founder of Greenpeace) urged the more widespread use of fission to reduce greenhouse gas emissions. As ever, there are three big problems with nuclear fission: waste that will be dangerous for a span longer than the existence of civilization thus far, the possibility of catastrophic accidents, and the connection between civilian nuclear capability and the proliferation of nuclear weapons. It is certainly becoming less clear-cut that nuclear is a worse option than the alternatives. For one thing, new reactor designs like the South African pebble bed promise to reduce the chances of accidents. On the proliferation side, there is talk of fuel supplier countries taking back spent rods, as protection against their plutonium being extracted and used for bombs. Of course, that just worsens the nuclear waste situation. The fact that it is all sitting in ‘temporary’ reactor ponds and that no state has constructed a permanent geological storage facility for radioactive waste should continue to give us pause.

Standing offer from the international community to the US

At the next UNFCCC conference of the parties (COP-13 / MOP-3), in Bali this December, the focus will be on devising an international agreement for the period after 2012. Obviously, an agreement that incorporates the United States would be a lot more viable than one that does not, though it is unlikely that the current administration would sign on to such an undertaking. As such, I wonder whether it might be possible or desirable to come up with an agreement that basically has a USA shaped hole in it: an open invitation for the United States to become involved after the 2008 election, with space having been set out for US participation.

If such an approach were taken, the choice about whether or not to bring the US ship into the port facility provided could become a significant political factor in the next election. The willingness of various candidates to accept or reject the offer could be one characteristic upon which the populace could evaluate them. Furthermore, having such an option from the outset would help avoid a situation where an agreement gets crafted – say – from 2012 to 2020, excluding the United States, and it then proves necessary to wait for the end of that commitment before an international regime including them may be devised.

I am just thinking off the top of my head here, but it seems like a potentially valuable strategy. Of course, the feasibility of any such approach depends upon a substantial proportion of the rest of the world being able to reach agreement on what ought to be done post-2012. It is difficult to predict, at this point in time, whether such consensus is likely to emerge.

Electric buses and a turn-of-the-century villain

Back when new technologies were just beginning to threaten the horse in urban transportation, a scam unrelated to the underlying technology may have set back electric vehicles, relative to their internal combustion counterparts. So posits this article in The Economist’s Technology Quarterly, in any case.

Between 1907 and 1909, electric buses traversed the streets of London. The company that built them was eventually driven to bankrupcy by the machinations of Edward Lehwess: “a German lawyer and serial con-artist with a taste for fast cars and expensive champagne.” After destroying the ability of the company to raise capital, he bought eight of the twenty electric buses for £800, then sold them to Brighton for £3,500.

At the very least, this demonstrates the ability of non-technological factors to significantly affect the fate of new innovations. At the most, it makes one wonder whether a more sustainable form of public transport could have gained dominance over the last century, to the benefit of the climate and those breating urban air.

Unpiloted drone to investigate ice caps

Melting sea ice was mentioned here recently. According to the MIT Technology Review, a team at the University of Kansas is building an unpiloted airplane designed to conduct detailed RADAR surveys of the Arctic and Antarctic ice sheets. In particular, the plane will look to see whether water has collected between glaciers and bedrock – a situation that can lead to their very rapid disintegration.

If things go according to plan the vehicle – dubbed ‘Meridian’ – should conduct its first survey next summer. Given the potential importance of melting ice for climatic feedback loops, anything that improves the quality of data available should be applauded.

Geography and the web

While it certainly doesn’t have the best name, the concept behind heywhatsthat.com is a neat one. Using data from Google maps, it generates panoramas as seen from mountaintops and other high places. You can then identify the mountains that you see around you.

The interface definitely needs some work, but the site does suggest ways in which openly accessible storehouses of data – such as the position and altitude information available from Google – can be combined into novel tools.

exploreourpla.net is a similarly badly named but interesting site. It combines geographic data and images related to climate change. You can, for instance, view a satellite map of Western Europe overlaid with luminous dots showing the most significant greenhouse gas emitters.

Big rocks in space

September 26th is the next full moon. That night, I recommend getting hold of a pair of field glasses and having a look at our closest significant stellar neighbour. In particular, note the large impact crater near the moon’s south pole. The Tycho Brahe crater was determined to be about 100 million years old, on the basis of samples collected by the Apollo 17 mission. While such craters soon fall victim to erosion from air and water on Earth, they are well preserved on the airless moon.

Such craters are not just of geological interest. They testify to the reality of impacts from comets and asteroids. A sufficiently large such strike could have devastating effects for humanity. In 2029, we will get a reminder of how close some objects are to hitting us, when the 99942 Apophis asteroid will pass so close to the Earth that it will be between communications satellites in geostationary orbits and us. For a while, this asteroid topped the Torino impact hazard scale. NASA estimates that the impact of Apophis would be equivalent to the explosion of 880 megatonnes of TNT: about 58,000 times the yield of the atomic bomb dropped on Hiroshima.

There is a small but real chance that the close pass of Apophis will alter its course such that it hits us on its next pass, in 2036. In response, a spaceflight subsidiary of EADS called Astrium is proposing a mission to learn more about the asteroid, study its composition, and investigate options for deflecting its orbit, if necessary.

In one sense, we are lucky with Apophis. It was discovered back in 2004 and has since had its orbit accurately tracked. A comet, by contrast, is essentially invisible until proximity to the sun causes it to melt and produce a tail. It is entirely possible that such an object could strike the Earth with little or no warning whatsoever.

Oceanic dumping of CO2

Carbon capture and storage (CCS) is a collection of technologies often mentioned in connection with global warming. Essentially, the idea is to capture the carbon dioxide emitted by things like power plants and then sequester it indefinitely in some sort of geological formation, such as a mined salt dome. While this idea is worthy of discussion in itself, my focus here is a number of approaches often described as CCS, but which do not achieve the same long-term result.

Some people have proposed that, rather than burying carbon underground, we just pump it into the sea. One option I am not going to discuss now is making big pools of liquid carbon dioxide in the very deep ocean. Rather, I will address the idea of using pipelines from shore or trailing from ships to release CO2 about 1000m down. Another alternative with similar effects is to make huge chunks of dry ice and throw them overboard, hoping most of the carbon will sink. Rather than being a type of CCS, these activities migtht be more accurately called ‘oceanic dumping of CO2.’

A matter of equilibrium

The problem here is both fundamental and intuitive. Think about a large plastic bottle of cola. With regards to the carbon dioxide, there is an equilibrium that exists between the amount dissolved in the liquid and the amount that is part of the air at the top of the bottle. As long as the system is closed (the cap is on), the amount of gas in air and water will trend towards that equilibrium point and, once the balance is achieved, stay there. This is what chemists mean when they say that equilibrium states display ‘constant macroscopic properties.’ CO2 from the water is still moving into the air, but it is now doing so at precisely the same rate as CO2 from the air is moving into the water. This is inevitable because if one rate were higher, the relative concentrations would change, and would continue doing so until the equlibrium was reached.

Now imagine that we change the equilibrium. If we take the cap off the bottle, the air inside mixes immediately with the air outside. Since the air inside has more CO2 than the air outside (because some of it has come out of the cola), this mixing causes the concentration of carbon dioxide at the surface of the cola to fall (we are ignoring the effects of atmospheric pressure in this analogy). As a consequence, the cola will start to release CO2, trying to get back to the old equilibrium between cola-dissolved and air-mixed gas. Since there is a lot more air, the equilibrium eventually reached will involve a lot less gas-in-cola. The cola goes flat. In the alternative, if we put a chip of dry ice into the cola and kept the cap on, a new equilibrium would eventually be reached in which both the cola and the air include a higher concentration of CO2.

Consequences

Dumping CO2 in the ocean thereby achieves two first-order effects. Firstly, it carbonates the sea, making it more acidic. Oceanic acidification is worrisome enough without such a helping hand. Secondly, it eventually results in an air-water balance of CO2 that is identical to the one that would have occurred if the CO2 started in the atmosphere. No matter which fluid it begins in, the same amount of CO2 at the same pressure will eventually result in the same balance between air-mixed and water-dissolved gas. It is just a matter of time. This is an important concept to understand, as it is the very heart of physical and chemical equilibria.

One big second order consequence results from this. If we do build such pipelines and do start carbonating the sea, people may decide that very carbon intensive technologies (such as coal generation or, even worse, Coal-to-Liquids) are environmentally acceptable. Using them in combination with oceanic dumping will inevitably have the same long-term atmospheric consequence as dumping the CO2 directly into the air.

Now, there is one reason for which oceanic dumping might be a good idea. Imagine there is some critical threshold for the atmospheric concentration of CO2: stay below it and things are reasonably ok, go above it and things all go wrong. In this scenario, it makes sense to store a bunch of CO2 and release it little by little. Of course, this only makes sense if we (a) only do this with CO2 we were inevitably going to release anyway (no new coal plants) and (b) aggressively cut future emissions so that the slow leak will not make us cross the threshold. Suffice it to say, this isn’t the kind of usage most advocates of CCS have in mind.

Precaution and bats

The ‘precautionary principle’ is frequently invoked in arguments about both security and the environment, but remains enduringly controversial. No matter how it is formulated, it has to do with probabilities and thresholds for action. Sometimes, it is taken to mean that there need not be proof that something is harmful before it is restricted: for instance, in the case of genetically modified foods. Sometimes, it is taken to mean that there need not be proof that something be beneficiail before it is done: for example, with organic foods. Sometimes, it has to do with who gets the benefit of the doubt, in the face of inconclusive or inadequate scientific data.

This article from Orion Magazine provides some interesting discussion of how it pertains to health threats generally, with an anecdote about rabid bats as an illustrative example.

I am not sure if there is all that much of a take home message – other than that people behave inconsistently when presented with risks that might seem similar in simple cost-benefit terms – but the article is an interesting one.

Truth in advertising

The kind of false environmentalism embodied in the Prius has been panned repeatedly on this site. Now, the government of Norway has decided that automobiles cannot claim to be “green,” “clean” or “environmentally friendly.” Bente Oeverli, a Norweigan official, explains that: “Cars cannot do anything good for the environment except less damage than others.”

Desalination

Water scarcity is a frequently discussed probable impact of climate change. As glaciers and snowcaps diminish, less fresh water will accumulate in the mountains during the winter; that increases both flooding (during wet seasons) and drought. Higher temperatures also increase water usage for everything from irrigation to cooling industrial processes. Given the extent to which the world’s aquifers are already depleted (see: Ogallala Aquifer), relatively few additional natural sources exist.

The big alternative to natural sources is the desalination of seawater. This is done in one of two ways: using multistage flash distillation or reverse osmosis. About 1,700 flash distillation plants exist in the Middle East already, processing 5.5 billion gallons of seawater per day (72% of the global total). These plants use superheated steam, a by-product of fossil fuel combustion, to pressurize and heat a series of vessels. As salt water flows into each successively lower pressure vessel, it flash boils. Condensers higher in the vessel cause the fresh water to precipitate out from the hot pressurized air solution. This is a simple process, but an energy intensive one.

Reverse osmosis, by contrast, uses a combination of high pressure pumps and specialized membranes to desalinate water. Essentially, the pressure drives fresh water through the membranes more quickly than the accompanying salts. As such, it is progressively less saline with each membrane crossing. In this process, there are both relatively high energy requirements (for high pressure pumping) and the costs associated with building and maintaining the membranes. Because it can be done at different scales, portable reverse osmosis facilities are the preferred option for combat operations or disaster relief.

Unfortunately, both processes are highly energy intensive. Particularly when that energy is being generated in greenhouse gas intensive ways, this is hardly a sustainable solution. Part of the solution is probably to sharply reduce or eliminate water subsidies – especially for industry and agriculture. More transparent pricing should help ensure that the whole business of desalination is only undertaken in situations where the need for water justifies all the expenses incurred.