Today will see the first national teachers’ strike for 21 years. Around 8000 schools will be disrupted, either partially or fully closed.

Teachers are skilled professionals. They do a tough job, working long hours and often enduring difficult working conditions. They also play a key role in society, so it’s important to attract good staff to the profession.

On the other hand, teachers are already well paid. According to Jim Knight, the Schools Minister (admittedly not a neutral source), the average salary for a teacher is £34000.

So there’s an interesting argument to be had about teachers’ pay.

However, for the most part that isn’t the argument that’s being had. Instead, the argument from the NUT (the teachers’ union that’s called the strike) that we’re hearing most is all about past levels of pay. Christine Blower, the NUT’s acting head, put it like this:

What we’re saying to the government is, if you really do value teachers, then make sure that they’re paid at least at the level of inflation - which we take to be the RPI [Retail Price Index], which is 4.1%.

The NUT’s argument is that the 2.45% pay rise that teachers have been offered is below the rate of inflation. If teachers’ pay rises more slowly than the rate of inflation, then their salaries will buy less than they used to; in real terms, teachers will have had a pay cut. And the NUT won’t stand for a pay cut.

There’s nothing in that argument about why a pay cut for teachers would be such a terrible thing, though. It doesn’t argue that teachers deserve more than they’ve been offered, or that a fall in teachers’ pay would hit recruitment, or anything like that. Instead, it’s a straightforward appeal to history, arguing that next year’s pay should be the same (in real terms) as last year’s pay.

Appeals to history are, of course, fallacies. That things were a certain way before doesn’t prove either that it was right that they were that way or that they should continue to be that way. The NUT needs to shift their focus to a better argument.

It probably wouldn’t be a great idea to try to explain that to your teacher, though. Except, perhaps, your Critical Thinking teacher.

Today the media have picked up on claims that the violence on Britain’s streets is a result of women consuming alcohol while pregnant. The story seems to have started with Scotland’s chief medical officer, Dr Harry Burns, reporting the connection to MSPs.

Pre-natal exposure to alcohol is thought to be linked to a wide range of physical and mental defects, including growth deficiency, learning difficulties, epilepsy, and (at a lower level) poor memory and general clumsiness. Children exposed to alcohol in the womb are even reported to have distinctive facial features, narrow eyes and thin upper lips. The name for these phenomena is Foetal Alcohol Spectrum Disorders (FASDs).

The idea that alcohol exposure damages unborn children is perfectly plausible; after all, it clearly damages adults. There’s still a little work to be done to show that alcohol consumption during pregnancy is a significant cause of violent behaviour on the streets of Britain, however, and certainly not enough in the media reports to do so.

The first thing it would be useful to know is whether the explanation being offered is sufficiently powerful. What proportion of pregnant women drink sufficient quantities of alcohol to cause FASDs? What proportion of children whose mothers drink that much alcohol display violent behaviour? How does this compare to the proportion of children whose mothers don’t drink that much alcohol who display violent behaviour?

Without knowing these things, we can’t know how much violent behaviour could be attributed to FASDs if the claim of a causal link were accepted, so can’t assess its importance as a possible cause of anti-social behaviour.

No doubt at least some of this information is out there (even if it didn’t make it into the media reports). However, there was a slightly concerning comment made in The Herald that the only large study of the prevalence of FASDs was in Italy. For a start, Italian drinking habits are rather different to those in Britain, so there has to be some doubt as to whether Italian findings are applicable here. The lack of corroborative studies also raises a doubt as to whether the connection is as well understood as the reports first made it seem.

Before questioning the significance of FASDs as a cause of violence, however, we should question whether they are a cause of violence at all. Assuming that a correlation between pregnant women drinking and their children tending towards violence has been found, how else might this correlation be explained?

One possible explanation would be that women with a disregard for authority are both (a) more likely to disregard medical advice not to drink while pregnant, and (b) more likely to rear children with a disregard for authority (and so with anti-social tendencies). In that case, a mother drinking while pregnant wouldn’t cause her child to be violent; rather, the mother’s drinking and the child’s violence would share a common cause: the mother’s disregard for authority.

There are other theories that could explain the data too. Perhaps living in a rough neighbourhood tends to drive women to drink and to draw children into gangs. Perhaps children who can steal alcohol from their parents are more likely to get drunk and so get involved in fights. Etc, etc.

Of course, there’s a chance that the claimed connection is real and we’re experiencing social problems in Britain because of pregnant women drinking. There’s also a chance that the scientific community has good reason to believe in this connection.

However, the evidence made available in the national press doesn’t show that there’s a correlation between pre-natal alcohol exposure and violent tendencies in this country, doesn’t show that the best explanation of such a correlation would be that pre-natal alcohol exposure causes violent tendencies, and doesn’t show that pre-natal alcohol exposure causing violent tendencies would explain the levels on violence on Britain’s streets.

For these reasons, the information presented in the media falls well short of demonstrating the connection between drinking and violence that is claimed.

We hear a lot about climate change and what we need to do to reduce carbon emissions and so preserve the environment.

One suggestion is that we should replace fossil fuel consumption with biofuel consumption, moving from burning coal and oil to burning ethanol and biodiesel.

Biofuels are liquid fuels made by fermenting plant material such as corn and rapeseed. Although they release carbon when burned, this is carbon aborbed by the plants when they’re grown. Fossil fuels, on the other hand, release into the atmosphere carbon which would otherwise be stored in coal and oil desposits underground. The impact on the environment of burning biofuels is therefore less than the impact of burning fossil fuels.

Or is it? Critics of biofuels point out that to fully understand their environmental impact we need to think more carefully than this.

The process of growing the crops used to make biofuels can be polluting, as can the process of converting the crops into fuel. Areas of rainforest, which act as a carbon sink, are being destroyed to make room to grow biofuel crops; whatever carbon would have been absorbed by the rainforest but now isn’t is a carbon cost of biofuel production.

It may well be that all things considered, biofuels are greener than fossil fuels, at least when they are produced in the right way. What we can’t do, though, is generalise from biofuels being greener than fossil fuels in one way (whatever carbon is emitted into the atmostphere when biofuels are burned is first absorbed when the biofuel crops are grown) to the conclusion that they are greener than fossil fuels full stop.