Monday, November 02, 2009
Reference: The decline of the caribou, Bangkok Post, November 2, 2009
It is reported that in 1989 there were 178000 Porcupine caribou in the Yukon and that "their number now is estimated to be 100,000" and from these data we may conclude that global warming is killing off the caribou because warming causes freezing rain in the calving season and that makes it hard for calving caribou to feed (The decline of the caribou, Bangkok Post, November 2, 2009). There are two things wrong with this analysis. First the data reported for 2009 was estimated by the authors to suit their purpose and it does not represent actual data. Second, if you don't cherry pick the start of the study period as 1989 but look at the entire available time series you get a very different picture because it shows that the population rose steadily from 100000 in 1972 to 178000 in 1989 and then decreased steadily down to 120000 in 2005. These data suggest, and caribou biologists agree, that caribou populations go through a 30 to 40 year cycle of growth and decay.This population dynamic cannot be related to global warming or carbon dioxide. Presenting only half of the caribou population cycle as a global warming phenomenon is just the kind of flimflam chicanery with which the war against carbon dioxide is now associated.