Science – Page 107 – a sibilant intake of breath

The acid sea

One frequently neglected consequence of rising global concentrations of carbon dioxide is increasingly acidic oceans (though it has been mentioned here before). Since the Industrial Revolution, the world ocean has absorbed about 118 billion tons of anthropogenic CO2: half of total human emissions. Every day, another 20-25 million tonnes are being absorbed.

Before the Industrial Revolution, oceanic pH was about 8.179. Now, it is at 8.104. By 2100, it is projected to be 7.824. Because pH is a logarithmic scale, that is a bigger change than it seems to be. At the projected 2100 concentration, the shells and skeletons of corals, molluscs, and phytoplankton with aragonite shells begin to dissolve within 48 hours. James Orr et al, writing in Nature provide many more details:

In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously.

The effect of more acidic oceans on aragonite is part of why the Stern Review projects that coral reef ecosystems will be “extensively and eventually irreversibly damaged” at less than 450 ppm CO2 equivalent and less than 2°C of warming. Given how critical coral reefs are to overall oceanic ecosystems – including key commercial fish species – this should be of concern to everyone.

It is very hard to project what the consequences of all this will be. As with so many other climatic phenomena, the net impact for human beings probably has to do with the relative strength of positive and negative feedbacks and the corresponding resilience of ecosystems. What is certain is that the only way to prevent acidification is to signficantly cut CO2 emissions.

Heat: How to Stop the Planet from Burning

During the past two years, I have been reading about climate change for several hours every day. During that span of time, I have read dozens of books and hundreds of articles. Quite possibly, none were as thought-provoking as George Monbiot’s Heat: How to Stop the Planet from Burning. If you are at all serious about understanding the issue of global warming, it is essential reading. He may not be right (indeed, it would be far preferable for him to be wrong) but he will definitely make you think.

His project is an ambitious one. Having decided that global temperatures must not be allowed to rise by more than 2°C on average, he works out what that would mean for Britain. Since British emissions per capita are way above the world average, a fair system would require much heavier cuts there than elsewhere. Canada’s per-capita emissions are even worse.

Here is a smattering of what he says will be required by 2030:

A power grid dominated by renewables and natural gas plants with carbon capture and storage.
Dramatically, dramatically tightened building regulations – making most houses either ‘passive’ in their non-use of heating or cooling or capable of producing their heat and power from piped-in hydrogen, possibly supplemented by solar.
Most private automobile travel replaced by a buses or non-motorized transport, both within and between cities.
An end to cheap air travel: no more low cost flights, with massive total cuts in the number of both short and long-haul flights.

The last is the result of a complete lack of alternative technologies that can deliver the kind of emission reductions required. Even if all other emissions were cut to zero, growth in air travel would make that one sector break his total limit by 2030.

Suffice it to say, Monbiot is not in the main stream of this debate. The Stern consensus is that climate change can be dealt with at moderate cost. Even if Monbiot’s ideas are entirely possible, in terms of engineering, one cannot help but doubt that any political party in a democratic state could successfully implement them. The impulse to defend the status quo may turn him into a Cassandra.

In fifty years, it is possible that people will look back at this book and laugh. Alternatively, It may be that they look back on Monbiot as one guy who had approximately the right idea while everyone else (Gore and company included) were in denial. The answer seems to depend upon (a) whether emissions need to be cut as much and as quickly as he thinks and (b) how bad it will actually be if they are not. It is pretty easy to do the math on the first of those, at least for any desired greenhouse gas concentration or temperature change. The latter is harder to assess. Regardless of which proves to be closer to the truth, this is a book I wholeheartedly endorse for anyone trying to keep abreast of the climate change issue.

Peak power, storage, and renewables

One characteristic of electricity poses severe challenges both for the drive towards lower carbon emissions and towards more power based on renewables: the fact that supply must precisely match demand at all times. On account of this, power plants are divided into two categories – base plants, which constantly provide the amount of power normally demanded by homes and businesses, and peaker plants, which provide some extra juice when everyone decides to turn on the air conditioning at once.

The first reason this is a problem is that peaker plants are much less efficient. It is costly to build an efficient oil or gas plant, and it just isn’t worth it to do so for one that runs relatively rarely. The second problem is more to do with the inconsistent nature of renewable power; the wind does not always blow and the sun does not always shine. As such, we need enough on-demand energy (usually based on fossil fuels) to fill the gap between what windmills can produce at time X and what consumers demand then. Plants on standby may not use much fossil fuel, but maintaining and operating them uses resources in a way that makes renewable options less appealing than otherwise.

The answer is obviously energy storage. We can build dams with two reservoirs, one uphill from the other. When power is in excess, we can pump water from the low reservoir to the high one. It can then be passed through turbines at times of peak demand to recover energy. Apparently, this can be done with efficiency of about 85%. Other options along these lines would be to have clusters of offshore wind turbines that use electrolysis to make hydrogen from seawater. That can be piped or carried to shore and used to produce carbon-free energy.

To me, it seems like another option is to use technology and incentives to help moderate power demand. If there are industries that can use a lot of power or a little, switching easily, then should be encouraged to become part of the swing capacity. It may even be worthwhile to store energy as heat in sinks or as kinetic energy in flywheels. If houses could heat or cool a block of material at the time when power is cheapest, then use that potential for heating or cooling across the day, we might need less peak capacity.

Some kind of competition for inventing fossil-fuel-free peak-power solutions may well be in order. If the technology exists, and there is enough of a cost differential between times of highest and lowest demand, it may well transpire that infrastructure can be built to normalize power demand on the scale of days, or even weeks.

The Khazzoom-Brookes Postulate

Reading through George Monbiot’s Heat, I encountered the idea of the Khazzoom-Brookes Postulate for the first time. The postulate relates to the effect of increasing energy efficiency on total energy usage and holds thas as the energy efficiency of industrial processes increases, total energy use actually rises as well. While initially counter-intuitive, the idea does seem to have some validity. If the energy cost of producing one tonne of aluminum falls from $5000 to $4000, you would expect aluminum companies to produce more. After all, their profit margin will have widened, all else being the same. The Celsias blog cites another example: if Boeing’s new 787 Dreamliner is 20% more fuel efficient, that just means that ticket prices will fall and more people will fly. Greenhouse gas emissions will stay the same or rise.

As Monbiot acknowledges, the postulate is controversial. It is certainly decidedly inconvenient for all the people who trot out ‘increased energy efficiency’ as the first (painless) means to combat climate change. Increased energy efficiency may be great for various reasons of convenience and enjoyment, but the postulate and accompanying logic does give one reason to doubt whether it can have a positive effect on reducing greenhouse gas emissions.

Sustainability and the Prius

One way or another, the Toyota Prius. is a symbolic vehicle. For some, it symbolizes how saving the planet can be relatively painless, enjoyable, and hip. You still get the same basic thing (the ability to zip around in a car) but without the guilt and with the important ability to lord it over the less environmentally responsible. Alternatively, the Prius is a symbol for the superficiality of the environmental commitments most people are willing to make. Seen in this way, it reveals how environmentalism is mere tokenism in many cases.

There are two arguments here which frequently become confounded. One is a first-order question about the ultimate sustainability of different energy systems. Is it sustainable to run internal combustion cars using cellulistic ethanol? What about plug-in hybrids charged using big nuclear fission plants? The answers to these questions are ultimately knowable to a high degree of specificity. For any given level of technology, answering them is simply a matter of applying chemistry and physics. The uncertainty therefore lies in estimations about what will be technologically possible at X or Y time.

The second-level argument is much more heuristic and intractable. There is the fundamentally liberal belief that environmental problems can be tackled fairly painlessly through a bit of cleverness and some new hardware. This is a view that takes the Prius as a positive symbol. At the other extreme is the conviction that only massive sacrifice can generate sustainability. The vision in Fight Club of people in rags pounding strips of leather on an abandoned superhighway captures this, and adherents would surely dismiss the Prius as a pathetic fig-leaf.

The latter argument seems to generate a lot more heated discussion, largely because the real meat of analysis on the former question lies in territory where most people cannot hold their own (who reading this could really calculate the efficiency of an energy grid based on photovoltaics, or of an industrial process for ethanol production from cellulose?). The latter debate requires only a will to participate, though it may not do much to leave us with an understanding of which view of the Prius is justified.

Responses to climate change scepticism

Thanks to a tip off from a new friend, I found this comprehensive collection of rebuttals written by Coby Beck and featured on the Grist website, which is itself well worth a look. The articles are sorted as follows:

Stages of Denial
Scientific Topics
Types of Argument
Levels of Sophistication

Whatever your beliefs, and whatever the case you want to make, you will find some points to engage with here.

Life improves with feta

Tonight, thanks to the cookbook Hilary sent me ages ago, I learned that a very nice pasta sauce can be conjured from onion, garlic, olive oil, basil, green beans, and nice tomatoes. Of course, what makes the whole dish work is the addition of little chunks of feta cheese on top at the end.

In Ottawa, I am planning to undertake several forms of self improvement. Better cooking is certainly on the list, as is rehabilitating my French. I am pondering whether taking some environmental science courses at Carleton or the University of Toronto would also be both possible and desirable. I would love to know more about climatic science, as well as the sciences more generally. Those who feel similarly may find this explanation of the difficulties involved in galactic colonization to be an interesting read.

James Burke’s Connections

I have mentioned it before, and may well mention it again. James Burke’s Connections is a television series worth seeing. Each episode wanders through history from one invention to another, with fascinating asides along the way.

As of this evening, someone put a stack of them on YouTube. The series was made at taxpayer expense by the BBC, so there is really no reason for which it shouldn’t already be available online for free. Watch a few episodes and you will learn a wealth of interesting (though often very esoteric) facts to break out at dinner parties.

As is generally the case when I am busy and need to come up with a blog post idea in a hurry, this was yanked from MetaFilter.

PS. By the end of each exam, I was coughing my lungs out. Now, I am taking little sips from my bottle of nasty tasting (and ineffective) cough syrup every three hours or so. Now, I feel like I have an especially nasty cold, with all the ill effects involved therein.

Haemodynamically responsive

How risky is climate change?

On his blog, Lee Jones posted a link to this book review. Basically, the argument is that people are (a) exaggerating the dangers of climate change and (b) using climate change as an excuse to pursue other ends. I would not deny either claim. The Intuitor review of The Day After Tomorrow is evidence of the first, and more can be found in many places. Of course, their review of An Inconvenient Truth suggests that not everyone is guilty of misrepresentation. As for smuggling your own agenda into discussions about climate change, I suspect that is equally inevitable. The question of how to behave justly in response to climate change is fundamentally connected to the history of economic development.

In an unprecedented move, I feel compelled to quote my own thesis:

While the IPCC has generated some highly educated guesses, the ultimate scale of the climate change problem remains unknown. On account of the singular nature of the earth, it is also somewhat unknowable. Even with improvements to science, the full character of alternative historical progressions remains outside the possible boundaries of knowledge. As such, in a century or so humanity will find itself in one of the following situations:

Knowing that climate change was a severe problem, about which we have done too little

Believing that climate change was a potentially severe problem, about which we seem to have done enough

Believing that climate change was a fairly modest problem, to which we probably responded overly aggressively

Observing that, having done very little about climate change, we have nonetheless suffered no serious consequences.

Without assigning probabilities to these outcomes, we can nonetheless rank them by desirability. A plausible sequence would be 4 (gamble and win), 2 (caution rewarded), and then 1 and 3 (each a variety of gamble and lose). Naturally, given the probable variation in experiences with climate change in different states, differing conclusions may well be reached by different groups.

As such, what it means to make informed choices about climate change has as much to do with our patterns of risk assessment as it does with the quality of our science. Exactly how it will all be hashed out is one of the great contemporary problems of global politics.