Category: Science

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

Farewell to horns

Cosmic bowling

This blog has previously mentioned the process of ‘fishing down’ marine food webs: you start with big delicious predator species (tuna, salmon, etc) and fish them to local extinction. Then, you catch smaller and less tasty things until the area of sea contains only plankton and jellyfish. This is a rational thing to do in the right circumstances: where access to a certain area of sea is free and unrestricted, and where everyone else is driving the resource towards destruction anyway. The best you can do individually is cash in while you can, since the resource is getting destroyed anyhow.

It seems that something similar is happening in relation to horns used for traditional Chinese medicine. Back in 1991, conservationists concerned about the decimation of rhino populations for medicinal purposes tried to encourage the use of Saiga Antelope (Saiga tatarica) horn instead. The World Wildlife Fund tried to encourage pharmacists to substitute the horns of the less endangered antelopes for those of the more endangered rhinos. Now, antelope populations in Russia and Kazakhstan have fallen from over 1,000,000 to just 30,000 (a 97% decline).

Switching from the unrestrained usage of one resource to the unrestrained usage of another just shifts the focus of the damage being caused. In order to create sustainable outcomes, restraint must be enforced either through economic means or regulation.

As an aside, there does seem to be some scope for reducing the horn trade by reducing demand through education. While horn is apparently an effective remedy for fever (though less good than available drugs not made from endangered species), the idea that it is an effective aphrodisiac can be countered. The rigid appearance of horn hardly makes it likely that it actually has chemical aphrodisiac properties, though it may strengthen the placebo effect already bolstered by general reverence for tradition. Apparently, the advent of Viagra has reduced prices and demand for rhino horn as well as seal and tiger penises that have traditionally been employed (though less effectively) to the same end.

Treating malaria

Vegetable stir fry

Legend has it that the gin and tonic cocktail evolved to provide the administrators of the British Empire with both ethanol and quinine. The former would keep them happy, and the latter would help keep malaria-carrying mosquitos at bay. In the present day, chloroquinine is still a common treatment for malaria. At 20-40 cents a dose, it is dramatically cheaper than the more effective alternative: a drug called artemisinin which is derived from the Artemisia annua shrub. A course of artemisinin treatment costs between $5 and $7 – too much for many people in the developing world.

Also problematic is how using artemisinin-only treatments will rapidly lead to drug resistance in mosquito populations. Mutations that confer advantages against a particular compound are relatively common, and are strongly selected for by evolution once they occur. It is much less likely that a malarial parasite will evolve both resistance to artemisinin and to a drug used in combination before one compound or the other kills it. As such, artemisinin combination therapies (ACTs) are the preferred treatment. These are somewhat more expensive, at $6 to$10 for a course of treatment.

Several organizations are trying to tackle the cost issue. In particular, the World Bank and the Bill and Melinda Gates Foundation are cooperating on a scheme called the Affordable Medicines Facility-malaria (AMFm). Given that malaria continues to kill 1-3 million people per year – and sicken between 400 and 900 million – such efforts are to be applauded and encouraged.

Some nuclear facts and figures

First Nations art

The first nuclear reactor to generate electricity was the EBR-1 experimental reactor in Arco, Idaho. Previously, reactors had only been used to produce materials for the military: especially plutonium for bombs of the kind dropped on Nagasaki on 9 August 1945. Four years after the EBR-1 reactor became operational (producing a paltry 100 kilowatts of power), it became the first nuclear reactor to suffer a partial meltdown.

The contemporary nuclear industry includes 439 nuclear reactors worldwide, producing 6.5% of the world’s energy and 15.7% of the world’s electricity. According to the International Atomic Energy Organization, 31 different countries operate reactors. Two countries – France and Japan – produce 57% of the world’s nuclear power, with nuclear producing 80% of all French usage. In terms of sheer output, the United States produces more nuclear power than anyone else in the world. US nuclear output in 2005 was about 406 terawatt-hours. They also have the largest and safest nuclear navy (Russia has had 18 serious nuclear accidents on subs, producing seven sinkings and 241 deaths).

As far back as 1952, a Presidential commission (The President’s Materials Policy Commission) produced a pessimistic report on the prospects of nuclear power for electrical generation, suggesting that money be devoted to solar power research instead. Now, the combination of concerns about energy security and concerns about climate change is prompting a possible re-birth within the industry. Here is a map showing who is considering new nuclear facilities.

It would certainly be useful to know the true price of nuclear power, as well as whether anyone will actually open a geological storage depot for spent fuel in coming years.

The biofuels controversy

Civilization Museum stairwell

Ricardo Hausmann, over at the Financial Times, has written an article on why biofuels are wonderful, not to mention the wave of the future. He says that current oil prices guarantee the long-term viability of biofuels, that there is lots of under-utilized land to grow them on, that the market can sort out the fuel/food issue, that higher profits for farmers from biofuel production will reduce government subsidies, and that developing countries will benefit because they have the most under-utilized land. Hausmann concludes that:

Standards will have to be developed to allow the energy and automotive industries to co-ordinate technologies. To make this scenario appealing, the impact of the expansion of the agricultural frontier on the environment and biodiversity, and the distributive effects of the rise in food prices will have to be addressed.

But these problems seem solvable given the expected political benefits in terms of lower net carbon emissions, more energy security, more efficient agricultural policies and greater opportunities for sustainable development.

While there is some reason to share his enthusiasm for biofuels, it is becoming increasingly clear that they have very serious (perhaps fatal) technical and ethical problems. The idea that biofuel profits will reduce government support for agriculture is also laughably naive.

Perhaps the most outspoken critic of biofuels is George Monbiot – British journalist and author of Heat: How to Stop the Planet from Burning. In his most recent article on the subject, Monbiot pans biofuels as both ecologically ineffective and ethically unsound. He argues that their purported climate change benefits are over-stated:

[Nitrous oxide emissions] alone ensure that ethanol from maize causes between 0.9 and 1.5 times as much warming as petrol, while rapeseed oil (the source of more than 80% of the world’s biodiesel) generates 1-1.7 times the impact of diesel. This is before you account for the changes in land use.

A paper published in the journal Science three months ago suggests that protecting uncultivated land saves, over 30 years, between two and nine times the carbon emissions you might avoid by ploughing it and planting biofuels.

He also argues that the drive towards biofuels will literally starve the poor, as farmers start using their land, water, and labour to fuel SUVs rather than feed people. He cites how Swaziland, in the grip of famine and receiving food aid, is nonetheless pushing to expand biofuel production from their main crop: cassava. His concerns do not seem unfounded, given how the amount of corn it takes to fill the tank of an SUV could feed a hungry person for a year.

Jean Ziegler, the United Nations’ independent expert on the right to food, has called biofuels “a catastrophe for the poor” and a “crime against humanity.” Such concerns deserve to be taken seriously. While it may ultimately be both possible and necessary to use biofuels for air travel (given the absence of any alternatives to liquid-fuelled engines for planes), it seems entirely possible that the drive towards biofuels for ground transport will further increase the harm being caused to the developed world and the biosphere by the unsustainable behaviours of the rich.

Climate and the rainforest

Civilization Museum Ceiling

Picture a square of tropical rainforest 100m to a side. According to a study from 2000, it is heavily laden with carbon: between 155 and 187 tonnes for wet forest and between 27 and 63 tonnes for dry. That means that each square kilometre of rainforest is holding between 2,700 and 18,700 tonnes of carbon: with about 70% of that in trees, 20% in the soil, and the rest in roots, understory, and litter.

Cutting down the trees for timber and to open farmland releases some portion of that stock into the atmosphere: with the amount dependent on how the soil’s carbon absorption changes and what is done with the wood and wood waste. When the forest is burned, either intentionally to clear land or unintentionally, the bulk of that carbon gets released into the atmosphere more of less immediately. As a result of both land use change and forest burning, the World Resource Institute estimates that deforestation represents about 18.3% of all human greenhouse gas emissions. As such, tackling it is a priority.

Arguably, the best thing individuals can do is refuse to eat meat or use first-generation biofuels. A considerable amount of cattle production takes placed in cleared areas of rainforest, with additional land cleared to grow soya to feed to cattle. On the biofuels front, there are both situations where rainforest is cleared directly for biofuel plantations (palm oil) and situations where the use of agricultural land to grow biofuel crops (corn) increases the overall need for agricultural land, pushing things like soy production into previously forested areas.

One other element to be aware of is the connection between population growth, urbanization, and deforestation. Several states actively encourage people to relocate from crowded areas to more sparsely populated zones bordering forested areas. Indonesia has sought to shift people away from Java in the same way Brazil has encouraged development in the Amazon to try to reduce crowding in the south.

Addressing deforestation is thus a two-fold proposition. In the first instance, the developed world needs to be aware of how commercial activities directly encourage deforestation. Restricting the use of tropical hardwoods, encouraging vegetarianism and veganism, and improving public transit would all help. Secondly, developing states must be encouraged to value their forests at a level high enough to prevent their destruction. That will probably require some kind of international financial instrument whereby the states actually protecting forests receive payments from all the states that benefit from ecological services those forests provide. The latter is a more wide-ranging solution, but the former can be more immediately implemented. If we are to keep that carbon in rich tropical soil and majestic tree trunks, action on both fronts needs to be undertaken.

Sources:

Climate ethics principles

Building in Old Montreal

Last November, the United Nations Framework Convention on Climate Change convened a meeting in Nairobi. One document that resulted from that meeting was the White Paper on the Ethical Dimensions of Climate Change (PDF). On the basis of arguments similar to those I have heard from Henry Shue and Stephen Gardiner, the document lists seven things that states intending to behave ethically on the climate change problem should do:

  1. Immediately acknowledge that they have a duty to reduce their emissions as quickly as possible to their fair share of safe global emissions;
  2. Immediately agree that an international greenhouse gas atmospheric stabilization target should be set as low as possible unless those who are most vulnerable to climate change impacts have consented to be put at risk from higher levels;
  3. No longer use scientific uncertainty or cost to their economies alone as justification for refusing to reduce GHG emissions;
  4. No longer refuse to reduce GHG emissions now on the basis that new less-costly technologies will be available in the future or that not all other nations have agreed to reduce their GHG emissions;
  5. Accept national targets for assuring that atmospheric concentrations of GHG are protective of human health and the environment that are based upon ethically supportable allocation criteria;
  6. Acknowledge that nations commit human rights violations that refuse to reduce their GHG emissions to their fair share of global emissions needed to protect those most vulnerable from climate change to loss of life, health, and well-being;
  7. Accept that those who are responsible for climate change have a duty to pay for costs of adaptation to and unavoidable damages from climate change.

Generally speaking, these are fine principles. If every major emitting state adopted them, it is entirely plausible that emissions could be brought down to sustainable levels within the next couple of decades and that the inevitable consequences of climate change from past emission could be equitably addressed. What the list fails to consider is the inherent Nash Equilibrium problem. States do not act as all states would act in an ideal world; rather, they generally act in a way that is rational given their inability to control the actions of other states. Given the Stern conclusion that mitigation is far less expensive than inducing and enduring climate change, it would be in the interest of all states to mitigate. Given how many states are proving reluctant to take that seriously, states that are serious about tackling the problem find themselves pushed towards a rationality of building up adaptive capacity instead of reducing emissions.

All that said, ethicists are not meant to be pragmatists. Having a well-argued idea of what ethical behaviour in the face of climate change would be provides a cognitive platform from which to evaluate current actions. It may also help to raise the overall profile of the issue in democratic states where moral and ethical argumentation can be an important element of the political process.

Small island states under threat

Milan Ilnyckyj in helmet and sunglasses

What can really be said about climate change and small island states? Working Group I of the IPCC projects that global sea levels will rise by 0.12 – 0.22m by 2100 not taking into account the melting of Greenland and Antarctica. With those elements factored in, a sea level rise of 1m certainly seems possible and it becomes conceivable that rises of several metres will occur if either of those icesheets goes the way of the polar icecap.

So what happens to the really low-lying states like the Maldives? The combination of coastal erosion, sea level rise, increased vulnerability to storm surges, and contamination of freshwater aquifers may well make them simply non-viable as places that can support a population. Nauru, Vanuatu, and Tuvalu face the same vulnerabilities – just to choose a few from among many examples.

A number of more substantial islands could be seriously threatened by the aquifer issue. Malta is suffering a double effect: rising sea levels threatening freshwater aquifers and decreased rainfall further increasing their salinity. In 2007, it doubled from 2000 to 4000 microsiemens and it is now too salty to water trees with. Fossil fuel based desalinators are being installed to help address water shortages: though they will increase Maltese GHG emissions.

All told, there isn’t much that can be hopefully said about low lying areas. Like the Arctic, these areas will certainly experience significant effects from climate change. The questions that remain are how serious and sudden it will be.

Increasingly clever machines

It seems my mountain climbing, robot-building friend Mark has a relatively new blog. He works with autonomous robots of the kind that competed in the recent DARPA Urban Challenge.

Here is one way in which such robots see the world: as a set of laser determined ranges.

Previous robot-related posts:

Death, drugs, and rock and roll

A recent study in the Journal of Epidemiology and Community Health confirms the hazards of musical stardom. The study examined the lives of 1,064 successful musicians in the rock, punk, rap, R&B, electronica, and new age genres. All became famous between 1956 and 1999 and all had records that were included in a ‘Top 1000 records of all time’ list from 2000.

It found that the median age of death for North American celebrities was an unimpressive 41.78. Europeans do even worse, at just 35.18. All told, successful musicians are nearly twice as likely to die early as members of the normal population.

The regional breakdown by cause of death is also interesting:

Cause – % in the US – % in Europe
Suicide – 2.8% – 3.6%
Drug or alcohol overdose – 15.3% – 28.6%
Chronic drug or alcohol disorder – 9.7% – 3.6%
Drug or alcohol related accident – 2.8% – 7.1%
Cancer – 19.4% – 21.4%
Heart disease – 18.0% – 3.6%
Accidents – 13.9% – 21.4%
Violence – 6.9% – 3.6%
Other – 11.1% – 7.1%

The largest single discrepancy is the probability of dying of a drug overdose, but lots of other significant differences exist. Neither regional profile suggests that music is a healthy profession: at least for those at the top.

Source:

Today’s best biofuel: Brazilian ethanol

Montreal graffiti

Many people see biofuels as a promising replacement for oil in transportation applications. Indeed, being able to replace the oil that contributes to climate change and must often be imported from nasty regimes with carbon-neutral fuels from domestic crops has a great deal of intuitive appeal. For this process to be worthwhile, however, there is a need to consider both life-cycle energy usage and net carbon emissions.

A study conducted in 2004 by Isaias de Carvalho Macedo at the University of Brazil focused on the production of ethanol from Brazilian sugarcane. This is considered by the majority of commentators to be the most energy efficient source of biofuel currently available. This is because most Brazilian sugarcane requires no irrigation and must only be ploughed up and replanted once every five years. The Macedo study found that producing a tonne of sugarcane requires 250,000 kilojoules of energy. This represents the need for tractors, fertilizers, and other elements of modern mechanical farming. The ethanol from one tonne of sugarcane contained 2,000,000 kilojoules of energy. Furthermore, the plants that produce it burn bagasse (the pulp left over when sugarcane has the sugar squeezed out) and can contribute net electricity to the grid. Corn ethanol (the kind being heavily subsidized in the United States) takes about as much energy to grow as is ultimately contained in the fuel.

In terms of net carbon emissions, cane ethanol is also fairly good. Using one tonne of ethanol instead of the amount of gasoline with the same energy content produces 220.5 fewer kilograms of carbon dioxide, when all aspects of production and usage are considered. Burning one litre of gasoline produces about 640 grams of carbon dioxide. Since ethanol has about 25% less energy than gasoline, the relevant comparison is between 1,000 kilograms of ethanol and 750 kilos of gasoline. The gasoline would emit 460 kilos of carbon dioxide, while the ethanol would emit 259.5 kilos.

This is an improvement over the direct use of fossil fuels, but not a massive one. The Macedo study concludes that widespread ethanol use reduces Brazilian emissions by 25.8 million tonnes of carbon dioxide equivalent per year. Their total carbon emissions from fossil fuels are about 92 million tonnes per year – a figure that increases substantially if deforestation is included.

The conclusion to be drawn from all of this is that ethanol – even when produced in the most efficient way – is not a long-term solution. Producing 259.5 kilos of carbon is more sustainable than producing 460, but it isn’t an adequate reduction in a world that has to cut from about 27 gigatonnes of carbon dioxide equivalent to five. Bioethanol may become more viable with the development of cellulosic technology (a subject for another post), but is certainly no panacea at this time.

References:

[Update: 8:54am] The above numbers on carbon dioxide emissions produced by gasoline per kilometre are disputed. If someone has an authoritative source on the matter, please pipe up.