Friday, May 22, 2009

Shuffling Stats to Suit

You don't have to wonder why people don't take global warming and climate change issues seriously when you read the following sort of stuff:
At his Victoria University of Wellington seminar in March, Bob [White] was armed with some startling facts:
combined searches on Google (through power usage) contribute to global warming as much as all plane travel;

cows contribute 18% of global warming, more than all the world's transport;
43% of New Zealand's greenhouse gases come from cattle and sheep;
the best thing that New Zealanders can do to reduce global warming is eat less meat.
Taking just the first item alone, it seems amazing that someone who claims to be a scientist should come out with such an unthought-through statement. In the (British) Sunday Times there was a similar recent comparison: with the Google search and the boiling of a kettle. Google's response is rather more measured: Others have used much higher estimates, claiming that a typical search uses "half the energy as boiling a kettle of water" and produces 7 grams of CO2. We thought it would be helpful to explain why this number is many times too high. Google is fast — a typical search returns results in less than 0.2 seconds. Queries vary in degree of difficulty, but for the average query, the servers it touches each work on it for just a few thousandths of a second. Together with other work performed before your search even starts (such as building the search index) this amounts to 0.0003 kWh of energy per search, or 1 kJ. For comparison, the average adult needs about 8000 kJ a day of energy from food, so a Google search uses just about the same amount of energy that your body burns in ten seconds.
On that basis we shouldn't we worrying about planes at all, but the people who travel in them!
David Galbraith deals with the issue of Google searches and planes:

“A recent study estimated the global IT sector generated as much greenhouse gas as the world’s airlines put together.”
This is a largely meaningless assertion since without the global IT sector people would have to use planes more. In addition, ‘global IT sector’ includes all of the computers required to design, build and operate aircraft, all of the computers used to search for and book trips, all of the computers used for in flight entertainment systems and all of the computers used by air traffic control.
In terms of moving people around to exchange information, if you wanted to make plane travel several million times more efficient, an Internet enabled computer is a viable alternative.
If you dare to search Google, after White's warning, you'll find all the media took up the cry of the cows (and sheep and other domestic animals) being the cause of more woes than cars. This 'sky is falling' piece of doomsdayism is based on a
"400-page report by the Food and Agricultural Organisation, entitled Livestock's Long Shadow, which also surveys the damage done by sheep, chickens, pigs and goats. But in almost every case, the world's 1.5 billion cattle are most to blame. Livestock are responsible for 18 per cent of the greenhouse gases that cause global warming, more than cars, planes and all other forms of transport put together."
But when you look at the way in which this theory is worked out, you find that cattle are supposedly responsible for a vast number of negative aspects of the industry, including the transporting of them. Now hang on: shouldn't the transporting go under the vehicle pollution box rather than the cattle box? Just reading the rest of the article (in the link under 400-page report) you start to scratch your head. It takes 990 litres of water to produce one litre of milk? HUH? Certainly the average cow isn't consuming that amount of water, so once again, the stats are being used to load onto the cow, when they're already loaded on elsewhere - or should be.
I'm not going to look at the other two items on White's list. In part they're already covered by point 2, and again, when you start to look at them in any depth, you find inconsistencies in the stats.
If scientists would stick to what they know - geophysics in White's case - they might come up with some better solutions for the real problems.
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