Thursday, June 19, 2003

Not such a hot analysis

'Global warming could trigger mass extinction', says a report on the Guardian's website.

Geologists at Bristol University have suggested that a global temperature increase of six degrees celsius was sufficient to wipe out 95 percent of species in the past. Since the Intergovernmental Panel on Climate Change (IPCC) has suggested that climate change in the next century could lead to a similar rise in temperature, the report concludes that a similar wipeout might occur in the next few decades. However, the IPCC figure of six degrees is a worst-case scenario and very unlikely. Moreover, humans have science and society on our side. We live in incredibly different climatic conditions across the world already. Not only will we survive, even if the most vivid speculations of climate panicmongers come true, but we have the wit to protect all the dumb animals, too.

Tuesday, June 17, 2003

SARS being contained - official

That seems to be the word coming from a conference in Malaysia to discuss the present state of play with the epidemic. So, this latest candidate as 'the Big One' has so far killed 799 people worldwide. More people die in Hong Kong alone from TB every year.

Sars 'contained' say experts, BBC News, 17 June 2003

Monday, June 16, 2003

Back in the saddle

Researchers in Belgium say that men who cycle are twice as likely to be impotent as those who do not cycle. They blame the saddles. Not the kind of report you want at the start of Bike Week, an attempt to get the millions of people who own bikes, but who do not use them, back on the road.

In the meantime, a colleague of mine had an accident on her bike recently. No other vehicles were involved, she just slid off at a roundabout. Even though she wasn't going that fast, she got a good bang on the shoulder and, very nearly, a good bang on the head. She doesn't wear a helmet, so we had a discussion about the dangers of riding without one.

Accident rates are actually very low, when compared to distances travelled, and are generally in decline. In 2001, the accident rates per 100 million kilometres travelled were:

In other words, my risk of an accident causing injury would be one accident every 200,000 kilometres or so. However, it is almost certainly the case that most minor accidents don't get reported, so that figure needs to be taken with a pinch of salt. On the other hand, we can be confident that the vast majority of serious accidents do get reported. There, the risk is one serious accident every 1.5 million kilometres travelled.

As for the effectiveness of helmets, this document by John Franklin is interesting in challenging the 'common sense' notion that wearing helmets is automatically better than not wearing helmets. However, looking at the overall figures, the increasing popularity of helmets does not seem to have reduced injuries. Where helmets are compulsory, the effect is to reduce cycling, not injury rates. He also notes:

1. Helmets are only required to be effective up to 20 kph (12.5 mph). So, helmets tend not to be successful at preventing serious injuries, only minor ones.
2. Many helmets aren't even that good.
3. There is a tendency for helmet wearers to engage in riskier behaviour.
4. Helmets may increase other forms of injury e.g. neck injuries

So, the jury is out on helmets. But talking about, and legislating in favour of, helmets tends to prevent people from cycling.

Impotence warning hits Bike Week, BBC News, 15 June 2003

The effectiveness of cycle helmets, by John Franklin