The environment – Page 140 – a sibilant intake of breath

Dating with carbon-14

When cosmic rays strike the atmosphere, they produce a radioactive isotope of carbon called carbon-14. This carbon gets absorbed from the atmosphere by living things. Once they die, they stop absorbing it. Since it continues to undergo radioactive decay after death, the ratio of carbon-14 to ordinary carbon declines in a predictable way in dead organic matter. This is the basis for radiocarbon dating.

When the great powers started testing nuclear and thermonuclear bombs during the Cold War, they doubled the ratio of carbon-14 to carbon-12 in the atmosphere. One consequence is the need to avoid contamination when radiocarbon dating. Another odder consequence is that you can determine the age of any person born since the tests began by looking at how much carbon-14 is in various layers of their tooth enamel. You just need to know whether they lived in the northern or southern hemisphere.

Of course, there are usually easier ways to determine the age of a living or dead human. This is just a demonstration of the extent to which the nuclear age is literally imprinted upon all those who live within it.

Cap and dividend

One intriguing form of carbon pricing that is being bandied about is the ‘tax and dividend’ approach. The idea is this: everybody pays a carbon tax on fuels and emitting activities. All the money is collected in a fund and redistributed evenly back to all taxpayers. As such, anyone who buys emits more than the mean quantity of carbon becomes a net payer and everyone who emits less actually gets back more than they pay. As mean emissions fall, so does the equivalence level of emissions – the point where you get back exactly what you paid.

For example, let’s imagine a tax that starts at a relatively modest $20 per tonne of carbon dioxide equivalent (CO2e). The mean Canadian produces about 23 tonnes of carbon a year, meaning they would pay $460 in carbon tax that year. That being said, the mean Canadian would also get back $460 as a dividend. A Canadian who is really trying (not flying, not eating meat, living in an efficient home, not driving, etc) might have much more modest emissions: say, 6 tonnes a year. They would pay $120 in carbon taxes and get back $460 – a nice ‘thank you’ for living a life that does less harm to others. Of course, someone who flies trans-Atlantically several times a year might end up paying significantly more in tax than they get back as a dividend.

Now say it is ten years on. The price of carbon has risen to $50 per tonne of CO2e and mean emissions per person have fallen by 25%. The break-even point is now 17.25 tonnes of carbon. As a result, someone who has not changed their lifestyle is now paying (23 – 17.25) * $50 or $287.50 a year in carbon taxes. If the 6 tonne person also managed a 25% cut, they would be earning (17.25 – 4.5) * $50 or $637.50 more in dividends than they paid in taxes.

These numbers are purely illustrative. It is possible that the per-tonne carbon taxes could be lower, and also possible that they would need to be much higher. In whatever case, the structure of the approach should be clear.

The approach has much to recommend it. For one, it is likely to enjoy the support of those already living relatively green lifestyles. For another, it has similar incentive effects to other carbon pricing schemes. It would encourage people to minimize or forego things with a heavy carbon burden, as well as make them more willing to invest in capital and technology that will reduce their carbon footprint.

Statistics in cryptanalysis and paleoclimatology

Reading Wallace Broecker‘s new book on paleoclimatology, I realized that a statistical technique from cryptanalysis could be useful in that field as well. Just as the index of coincidence can be used to match up different ciphertexts partially or completely enciphred with the same key and polyalphabetic cryptosystem, the same basic statistics could be used to match up ice or sediment samples by date.

As with the cryptographic approach, you would start with the two sections randomly aligned and then alter their relative positions until you see a big jump in the correlation between them. At that point, it is more likely than not that you have aligned the two. It probably won’t work perfectly with core samples – since they get squished and stretched by geological events and churned by plants and animals – but an approach based on the same general principle could still work.

Doubtless, some clever paleoclimatologist devised such a technique long ago. Nonetheless, it demonstrates how even bits of knowledge that seem utterly unrelated can sometimes bump up against one another fortuitously.

Personal net carbon removal

Those wanting to reduce their contribution to climate change are generally presented with two options: cut back on your own emissions or pay someone else to do so. The first requires sacrifice and/or time and/or capital. You can give up flying, meat, and air conditioning; you can take trains instead of planes; you can invest in solar panels and ground source heat pumps. The second set of options is arguably more practically challenging and morally problematic. It is harder to verify that someone else has actually cut emissions, and done so in response to your payment rather than any other incentive. There are also those who think it unacceptable to buy your way out of taking action yourself.

There is, at least theoretically, a third option. Suppose I buy an area of land in British Columbia. The place is ideal for growing trees and the trees on the lot grow each year, absorbing carbon from the air in order to do so. As a result, my little forest is a net carbon sink. The danger, of course, is that the carbon will be re-released. Someone might cut down my forest. My forest might dry out or burn down (possibly because of climate change). Then, I will have accomplished little of value, given that carbon dioxide has a long atmospheric life. For most intents and purposes, it may as well never have been absorbed.

What I need to do is ensure the carbon doesn’t go anywhere. Here are some options I have come up with:

Cut down trees at the growth rate (if one matures per month, cut one per month). This ensures that the forest will always be absorbing the same amount of carbon per unit time. Then, encase the lumber in something durable and air tight – keeping the carbon inside sequestered indefinitely. Then, either use the wood as building material or simply bury it.
Cut down trees as described above and bury them somewhere they are relatively unlikely to decompose: such as a peat bog or the Arctic tundra.
Cut down trees as described, chop them into chips, burn the chips for energy, capture and sequester the carbon dioxide underground. This approach has some variants: (a) seperate oxygen from air and burn the chips in that to produce gaseous outputs that are mostly CO2 or (b) convert the biomass chips into syngas (hydrogen and carbon monoxide) before combustion.

Of course, there are issues with all of these:

Is it possible to shrink wrap wood in a way that will keep the carbon inside indefinitely? How many carbon emissions would be associated with making the shrink wrapping material?
The Arctic tundra is melting, threatening massive carbon releases. Global temperature rise could do the same to peat bogs.
This may require tens or hundreds of millions of dollars worth of capital and skilled labour, depending on how much all the equipment costs. Nobody could do this alone, though it may be possible to do at a commercial scale, partly in exchange for payments from those having their emissions offset.

None of these are great options, but they do offer at least the logical possibility of actually, literally offsetting one’s carbon emissions. For those with aspirations for world travel, but also serious ethical concerns about climate change, such options may prove the only choice.

Oil’s next century

With oil prices at levels rivaling those during the crises of the 1970s, virtually everyone is clamouring for predictions about medium and long-term prices. Those concerned about climate change are also very actively wondering what effect higher hydrocarbon prices will have.

In order to know what the future of oil looks like, answers are required to a number of questions:

How will the supply of oil change during the decades ahead? How many new reserves will be found, where, and with what price of extraction? How much can Saudi Arabia and Russia expand production? When will their output peak?
How will the demand for oil change? How much and how quickly will high prices depress demand in developed states? What about fast growing developing states like India and China?
At what rate, and what cost, will oil alternatives emerge. Will anyone work out how to produce cellulosic ethanol? Will the development of oil sands and/or oil shale continue apace?
What geopolitical consequences will prices have? If prices are very high, will that prove destabilizing within or between states?
Will the emerging alternatives to oil be carbon intensive (oil sands, corn ethanol) or relatively green (cellulosic ethanol, biomass to liquids)?

Of course, nobody knows the answer to any of this with certainty. There are ideological optimists who assert that humanity will respond to incentives, innovate, and prosper. There are those who allege that oil production is bound to crash, and that civilization as we know it is likely to crash as well.

Mindful of the dangers of prediction, I will hold off on expressing an opinion of my own right now. The magnitude of the questions is far too great to permit solution by one limited mind. What contemplating the variables does allow is an appreciation for the vastness and importance of the issue. Virtually any combination of answers to the questions above will bring new complications to world history.

Natural laboratory for ocean acidification

One of the larger unknowns when it comes to the impact of human carbon dioxide emissions is the degree to which living things will be harmed by more acidic oceans. This is occurring because water with more CO2 dissolved in it is more acidic. There are concerns that overly acidic sea water might compromise the ability of organisms with shells made of calcium carbonate to build and maintain their bodies. Other affects on marine ecosystems are anticipated, though it is challenging to assess what their magnitude will be and when they will occur.

Scientists recently completed a study of a place where such effects are occurring naturally due to carbon dioxide venting from the sea floor:

Around the vents, [pH] fell as low as 7.4 in some places. But even at 7.8 to 7.9, the number of species present was 30% down compared with neighbouring areas.

Coral was absent, and species of algae that use calcium carbonate were displaced in favour of species that do not use it.

Snails were seen with their shells dissolving. There were no snails at all in zones with a pH of 7.4.

Meanwhile, seagrasses thrived, perhaps because they benefit from the extra carbon in the water.

The latest IPCC estimate is that global pH will fall from 8.1 today to about 7.8 by 2100. Greater than expected CO2 emissions would cause a larger change. Coral reefs are especially likely to suffer.

Oceanic acidification is the inevitable result of adding CO2 to the atmosphere, but it not otherwise causally connected to climate change. It does add a complication to any plan that seeks to reduce global temperature change through a means other than reducing CO2 emissions; even if more energy could somehow be reflected or dissipated into space, the marine consequences of acidic oceans would endure.

Dyson’s carbon eating trees

The New York Review of Books recently featured a couple of book reviews by Freeman Dyson. In them, he shares some interesting ideas:

There is a famous graph showing the fraction of carbon dioxide in the atmosphere as it varies month by month and year by year
[The graph features] a regular wiggle showing a yearly cycle of growth and decline of carbon dioxide levels. The maximum happens each year in the Northern Hemisphere spring, the minimum in the Northern Hemisphere fall. The difference between maximum and minimum each year is about six parts per million.
The only plausible explanation of the annual wiggle and its variation with latitude is that it is due to the seasonal growth and decay of annual vegetation, especially deciduous forests, in temperate latitudes north and south.
When we put together the evidence from the wiggles and the distribution of vegetation over the earth, it turns out that about 8 percent of the carbon dioxide in the atmosphere is absorbed by vegetation and returned to the atmosphere every year. This means that the average lifetime of a molecule of carbon dioxide in the atmosphere, before it is captured by vegetation and afterward released, is about twelve years.
[I]f we can control what the plants do with the carbon, the fate of the carbon in the atmosphere is in our hands.
Carbon-eating trees could convert most of the carbon that they absorb from the atmosphere into some chemically stable form and bury it underground. Or they could convert the carbon into liquid fuels and other useful chemicals.

This is, of course, a geoengineering scheme. As such, it is subject to the two major points of opposition: that we don’t know whether it would work, and that it would probably produce unwanted and unpredictable consequences. That being said, it seems less dangerous in the latter regard than schemes to fertilize oceans or fill the air with aerosols. Ideally, these enhanced trees would just behave like a larger number of normal trees.

Genetic modification of plants is likely to play a role in addressing climate change. Food crops are an obvious area where that is true. They may need to be made more resistant to heat, extreme weather, drought, and floods. They may even need to have their photosynthetic pathways altered. If, along the way, we come up with a mechanism for producing trees that eat more carbon, it could make a useful contribution to the overall effort.

We should not, however, forget the third big danger connected to geoengineering: the risk of falling into the complacent belief that technology will bring an answer. Super carbon eating trees are a long-shot – one worth considering, perhaps, but no excuse to keep on burning forests and coal.

Capturing waste heat

Comment threads on this blog have previously been rife with discussion about boosting the efficiency of industrial processes through the use of waste heat. It does seem intuitively undesirable to have something like a nuclear power plant venting a significant portion of the total energy being expended from fission in the form of hot air or water being dumped out into the natural environment.

A machine installed at Southern Methodist University demonstrates that there are situations where waste heat can produce a decent amount of electricity (50 kilowatts) at an acceptable cost, and with a payback period of just three or four years. The machine uses an Organic Rankine Cycle, in which a high molecular mass organic fluid is used to convey the waste heat. This is necessary to produce useful work, and eventually electricity, from relatively low temperature sources. As energy prices continue to rise, you can expect to see more such equipment being developed and deployed.

Almost nothing is sustainable

Sustainable development’ is an expression that you hear a great deal. It was famously defined by the Brundtland Commission as meeting the needs of the current generation without sacrificing the ability of future generations to meet their own needs. This seems sensible enough, but it raises two major questions: how do we identify the ‘needs’ of this generation, and how do we anticipate the capabilities of future ones.

Most talk of sustainability these days is nonsense. The simple reason for that is that very little of what we do is sustainable. Nothing dependent upon fossil fuels is sustainable, so there go most of our forms of transportation, a lot of our electrical generation, and most of global agriculture. Nothing that destroys the long-term productivity of agricultural land is sustainable, but much of our agriculture does just that. Continually requiring more fertilizers to cope with loss of soil nutrients is not sustainable. Virtually no fisheries anywhere in the world are used in a sustainable way (none when you consider the impact climate change will have on them). Finally, nothing that contributes to accelerating climate change is sustainable; that doesn’t really create sharp categories between what is or is not sustainable. Rather, it gives an idea about the total intensity of all the greenhouse gas emitting things we undertake must be.

What does this generation need?

The matter of defining the ‘needs’ of the current generation is enormous and partially irresolvable. At one absurd extreme is the flawed idea that people have the right to continue living as they always have. Asserting this is akin to a French aristocrat facing the guillotine, arguing that his life of privilege so far justifies more privilege in the future. We cannot have a right to something that demands unacceptable sacrifices from others – particularly when that right hasn’t been earned in any meaningful way. At the other extreme is the assertion that nobody has any right to material things and that people starving around the world and dying from treatable, preventable diseases have no credible moral claim to additional resources. Somewhere between the two lies the truth. The important thing isn’t to work out precisely where, but to generate a universal understanding that constraint is going to need to be a part of human life, if we are to survive in the long term.

Arguably, ‘needs’ are entirely the wrong way to think about things. Instead of starting with who we are and what we want, perhaps we should start with what there is and what impact that has on how we can live, where we can be, and how many of us there can be at any one time.

How capable will future generations be?

The matter of the capabilities of those in the future is similarly challenging. Our expectations about the future produce a ‘treadmill’ effect, where we expect added financial wealth and improved technology to make future generations better off despite how more resources have been depleted, more climatic damage done, and more pollutants released into the environment. If people in the future are super-resourceful technological wizards, the degree of restraint we need to observe in order to accommodate them is small. No wonder this belief is so popular among those seeking to defend the status quo.

Of course, it is possible that future generations will have less capability to satisfy their needs than we do. Most obviously, this could be because of the depletion of fossil fuels (a vast and easily accessed form of energy) or because of the impacts of climate change. To some extent, we need to take such risks into consideration when we are deciding what duties we owe to future generations. Any such consideration will require passing along more resilience, in the form of more resources and a healthier planet.

What might sustainability look like?

Quite possibly, the only people in the world living sustainably are those in small agricultural communities with little or no connection to the outside world. Since they do not import energy, they must be sustainable users of it. Even such communities, however, need not necessarily be sustainable. Unless they have a low enough population density to keep their food production from slowly degrading the land, they too are living on borrowed time.

Producing a sustainable global system probably requires all or most of the following:

The stabilization of global population, perhaps at a level significantly below that of today.
The exclusive use of renewable sources of energy, derived using equipment produced in sustainable ways.
Agriculture without fossil fuels, and with soil and crop management sufficient to make it repeatable indefinitely.
Sustainable transport of old (sailing ships) and new (solar-electric ground vehicles) kinds.
The preservation of ecosystems that provide critical services: for instance, tropical forests that regulate climate.
An end to anthropogenic climate change.

While it is technically possible that we could manage to build problems and solve them through clever technology indefinitely, it does seem as though doing so is risky and probably unethical. It may be more prudent to begin the transition towards a world unendingly capable of providing what we desire from it.

Selling ‘clean coal’

In the spirit of the laughable ads from the Competitive Enterprise Institute, there is a new offering from the coal industry. The strategy seems to be shifting from “there is no reason to believe in climate change” to “anything that would harm the fossil fuel industry would cause unacceptable harm to consumers.”

‘Clean coal’ will always be a non-sensical statement, given the environmental damage done by coal mining, the toxic emissions, and greenhouse gasses. Even with carbon sequestration, coal will be a dirty way of generating power. Furthermore, it seems unlikely that coal in combination with carbon capture and storage will be a source of cheap energy. As the cancellation of FutureGen due to cost overruns suggests, clean coal isn’t cheap.