Food, energy, and fossil fuels

Yesterday night, I had an interesting conversation about energy, fossil fuels, agriculture, and human population. The key fact is that global agriculture is now deeply dependent on fossil fuels. They are needed for everything from running industrial farming equipment to producing fertilizer to operating the vast logistical networks through which food is processed and distributed. The key question is, what will the ramifications be when we inevitably transition from a global energy system based on fossil fuels to one based on renewable sources?

The transition is indeed inevitable, though it could happen in either of two ways. Either we can voluntarily cut back on using fossil fuels due to well-founded concerns about climate change – and awareness of the opportunities that exist in renewable energy – or we will draw down reserves to the point where it takes more energy to extract one calorie worth of fossil fuel than the fuel contains.

So, what might the post-fossil-fuel world look like? To get one idea, we can consider the world as it existed before the Industrial Revolution brought about large-scale fossil fuel use. Back in 1500, there were about half a billion people alive on Earth. The energy they relied upon was overwhelmingly from renewable sources, such as the embedded solar energy in plants. It seems plausible that returning to that kind of an energy system would return the planet’s capability of sustaining human beings to about the level that existed then: a bit higher, perhaps, because people now live in more places, and a bit lower, perhaps, because of the damage we have caused to the planet in various ways.

For an alternative, we need to consider an enhanced renewable-backed future that includes clever approaches to harnessing renewable sources of energy: solar, wind, wave, geothermal, etc. It seems to me that if we are going to have a world that does not use fossil fuels and which sustains something like as many billions as are alive now (to say nothing of in 2050 or later), such technologies are going to need to be deployed on massive scale and the world’s agricultural systems will need to be adapted to rely on them.

Fossil fuels have been an enormous energy boon for humanity. Quite possibly, they have allowed us to far overshoot where we would otherwise have been, in terms of energy use and population. Quite possibly, both of those will need to fall substantially in a post-fossil-fuel world. If there is any chance of that not taking place, it will depend on the massive deployment of the kind of advanced renewables that are already technologically feasible. That deployment will take dedication, foresight, financing, and energy. Indeed, there is surely no better use for whatever proportion of the world’s remaining fossil fuels we choose to burn than in making the solar and wind farms that will need to form most of the future energy basis for all human civilization.

Latent heat and storms

When energy is used to heat something up, the temperature does not increase smoothly as the energy is put in. Most significantly, this is because causing matter to change states takes energy in itself, above and beyond the energy that goes into warming. Imagine a big block of ice at 0°C. A lot of energy has to go into it before it becomes a pool of water at 0°C. The same is true for turning 100°C water into 100°C steam. Latent heat has been discussed here before.

Because of climate change, the overall trend in global air temperatures is going upward. As anyone who has visited a steam room or had a camera fog up when coming inside on a cold day knows implicitly, warmer air can hold more water. As well as being an important feedback effect (since water vapour is a greenhouse gas), warmer more air-laden water contains more of the latent heat that provides the energy for thunderstorms, tornadoes, and hurricanes. The increase in the average amount of latent heat in a body of air increases the probable strength of future storms, a fact that becomes especially worrisome when you acknowledge how the damage caused by storms increases in a non-linear way. Winds that are 10% faster have a third more destructive potential.

The extra water in the air will also increase the quantity of precipitation and the likelihood of floods. Furthermore, melting ice sheets will cool sea water, increasing the temperature differential between the equatorial and polar regions. This will increase the strength of mid-latitude cyclones, as air currents cooled by melting ice sheets (latent heat, again) collide with ever-warmer masses of air, containing ever-more water. The level of melting in the ice sheets is already significant enough to measure using sensitive gravitational data from satellites like GRACE. Greenland is losing about 100 cubic kilometres of ice per year, while West Antarctica is losing it at a somewhat smaller rate. The ‘wet’ process of ice sheet disintegration suggests that the rate of ice loss could increase dramatically, one the ice sheets are pushed past a critical point by warming.

Climate change art

Plants, rust, concrete

Do we need climate change art?

I would say we do. Art inspires people to think beyond their experience and grasp the implications of trends. It also motivates people emotionally in a way that scientific analysis can be hard-pressed to do. (Indeed, does only by accident, since scientific reports are not written to evoke emotional responses.)

Has any important climate change art emerged? (Weird sculpture outside 111 Sussex aside) Is there a danger that art that plays upon the worst fears evoked by climate science will be counterproductive? Can art help us to really grasp the danger, without the need for costly disasters to prove the link from greenhouse gasses to climate change to danger to humanity?

Preserving plastic history

Cracks in the roof of a bus stop

Over at Slate, there is an interesting article about art and chemistry: specifically, about the challenges involved in preserving artwork and historical objects that were made from fundamentally unstable plastics. As the article points out, this is an odd reversal of what most of the world is trying to do, namely eliminate plastic wastes that are proving far more durable than would be ideal. For instance, there is the worrisome North Pacific Gyre: a huge garbage patch in the deep ocean.

One interesting aspect of the Slate article is the assertion that some microorganisms can now digest plastics. This claim contradicts those made in Alan Weisman’s excellent book The World Without Us, in which he claims that such metabolic pathways had not yet evolved.

The overall question of materials over long spans of time is certainly an interesting one. They have a huge impact on what we do and can know about history. For instance, much of what we know about ancient peoples comes from examinations of the garbage and artifacts they left behind: clues that can give insights into diet, contact with other groups, and much else besides.

The the amount of material and information being accumulated in the modern world is unprecedented, the plight of the plastics curator is another example of how much of it is ephemeral. Perhaps that is more true of information than anything else. When the plastics and metals and dyes of our optical disks, hard drives, and flash memory systems start to degrade and fail, an unprecedented amount of information is likely to be lost, from baby and wedding photos to documentation of historical events.

Carnot efficiency

Twist 1.5, Major's Hill Park, Ottawa

For a bit of light entertainment, I have been reading Tom Rogers’ book Insultingly Stupid Movie Physics, which basically covers the same terrain as his entertaining website, though at greater length and with more detail. Of course, one can never entirely escape climate change related information, and the book includes a discussion of Carnot efficiency: the maximum theoretical efficiency with which heat engines can convert thermal energy into useful power.

The efficiency depends on two factors: the high temperature produced using combustion, solar energy, geothermal energy, etc, and the cold temperature where the heat is expended into the surrounding environment:

Efficiency = ( 1 – Cold temperature / Hot temperature ) * 100

This has implications for technologies like the co-generation of heat and power. If the heat source for a power plant is 375°C (648°K) and it is dumping waste heat into 10°C (283°K) outdoor weather, the Carnot efficiency is about 56.3% (the actual efficiency is lower, for various reasons). If, instead, it is dumping the heat into buildings at 25°C (198°K), the Carnot efficiency falls to 54.0%. In a case where the heat source is just 200°C (473°K), the difference between a 10°C cold area and a 25°C cold area cuts the Carnot efficiency from 40.2% to 37.0%. In many cases, cogeneration is still worthwhile, despite the loss of useful electrical or kinetic energy, but it should be appreciated that the redirection is not without cost.

Carnot efficiency also helps explain why waste heat is not always worth capturing. If the temperature difference between the source and an available destination for the thermal energy is not large, there isn’t much useful power that can be produced.

[Update: 4:47pm] Remember to express the temperatures in Degrees Kelvin, by adding 273.15 to the figure in Degrees Celsius.

Embassy artwork

Ugly statue outside the American Embassy, Ottawa

The city of Ottawa is quite well provisioned with public art. Some pieces, like the wooden spiral in the park near the mint, are quite charming. The piece above, located in the US embassy compound, is probably the worst of the lot.

As you can see, the sculpture looks a bit like a balloon animal where the balloons have been replaced by black steel beams and the angles have been randomly altered by twenty or thirty degrees. Sitting within a perimeter fence that never contains a visible human, the statue also symbolizes how faceless and harsh the whole compound is.

While concerns about security are obviously of enormous importance for an American diplomatic facility, nothing about them seems fundamentally at odds with good taste. A less ghastly bit of art, and an embassy that somehow demonstrates that the United States is a nation full of people basically just like Canadians rather than an imposing neo-military facade, might be a start along that road.

P.S. In the spirit of fairness, it should be noted that the British High Commission is equally externally unpopulated and far more lacking in architectural virtue.

P.P.S Two other statues notably for their oddness and lack of aesthetic appeal are the strange rocket ship / polar bear statue at the building formerly intended to become city hall and the giant evil spider outside the National Gallery.

Comprehensible art

Perhaps my favourite thing about Vladimir Nabokov is how he never sacrifices clarity for the impression of brilliance. So many great modern authors seem to take delight in baffling their readers, whether with torturous sentences, incomprehensible plots, or surrealism. James Joyce is especially guilty, but hardly alone, in his use of such approaches. While such writing can push the boundaries of language, it is likely to try one’s patience as well. As such, it is especially pleasant to see genius expressed in a straightforward form: excellence in a fairly traditional format.

It’s rather like the different kinds of modern art. There may be some profound idea in the mind of the artist who has splattered a crumpled canvas with Burger King condiments, but I have a lot more respect for the one who made the elegant sculpture in wood or marble or bronze.

Luminox

Luminox in Oxfordshire

The Luminox festival is really quite something. Essentially a celebration of combustion, it runs all along Broad Street from 7:00pm to 10:00pm for the next two days. The event involves a combination of fire-based artistic displays and live music. The whole thing seems to be paraffin powered, and it includes both static displays and manned installations that are made to flare up with the removal of chokes. Spaced along the road are braziers of coal and wax-burning metal chimneys that glow orange hot. Hanging from a crane beside Balliol College is a massive chandelier of flame.

Having such an immediate experience with fire would be impossible in lawsuit-happy North America, but it is quite engaging and beautiful. I actually took about fifty pictures, so expect to see them crop up on future days when I am too busy to find something new.

PS. Today, I also saw the inside of the Green College tower tonight, and got a photo of Mansfield for my growing collection of Oxford college images.

PPS. Did you know that you can set Google Calendar to automatically notify you of upcoming appointments by SMS? During the breaks, I have trouble keeping track of exactly which generally unstructured day I have an event in. With this free service, I have a very helpful aide memoire.

Early birthday gift

Klein Bottle in WadhamAs soon as I saw the box from Meghan in the porter’s lodge, I knew that there was a closed, non-orientable, boundary-free manifold in Wadham. Despite my birthday not being for another four days, not opening it at that point would have been pointless and superfluous. After all, it is better to have a Klein Bottle on display than a Klein bottle which you know to be in a box. I trust that Meghan will understand.

As you are like to find in the office of a particularly cool mathematician, it is a genuine Klein Bottle: such as you would get if you could glue the edges of two Mobius strips together. While that is not actually possible in three dimensional space, the Klein Bottle is a three-dimensional cross section of that higher dimensional object. Imagine, for a moment, a hair elastic twisted into a figure-eight shape. In three dimensions, you can do that without having it intersect itself. If you were to draw that figure-eight hair elastic, however, or take a photo, it would look as though it intersects itself. The same is true of a Klein Bottle embedded in three dimensional space. Note that even if our universe really does have ten spacial dimensions, or more, as postulated by string theory, there are still only three of them unfurled enough to put parts of a glass Klein Bottle in.

Invented by Felix Klein – a German professor of mathematics – in 1882, a Klein Bottle has only one side (no inside and outside like a balloon), yet also no rim or lip (like a bowl or an open wine bottle). It’s the only gift I’ve ever received that I printed off an encyclopedia article about, for use in explaining to guests. You can also tell people it’s a work of modern art.

Many thanks Meghan, for furnishing me with what may be the geekiest thing I have ever owned. Like surviving through a battle in which your friends died, getting a Klein Bottle creates a commitment to live the rest of your life in a certain spirit. It’s also dramatically quieter than my rock tumbler used to be.