Thursday, July 19, 2007



Climate change: flatlining transport emissions?

Over the past year I've ocasionally speculated that rising fuel prices would put an end to (or at least slow) the trend of rising transport emissions. And looking at the consumption figures from this year's Energy Data File, it looks like I was right:

(Source: Ministry of Economic Development, Energy Data File June 2007, Table D.7, p. 51)

The long-term trend is even more stark. Between 1995 and 2005, petrol consumption rose by an average of 1.3 percent a year. Last year, that growth slowed to 0.1%. Over the same period, diesel consumption rose by an average of 4.6% a year. Last year, it grew only 0.7%. High prices seem to have flatlined demand growth - which is a Good Thing from an emissions perspective.

Unfortunately, it won't last. Prices this year have been lower, so demand growth (and hence emissions growth) may have returned to its old path. And with the dollar pushing US$0.80, it's only going to get worse again. If we want to stop this, we need to both incoporate the cost of carbon into transport fuel prices and make serious efforts to push people towards more fuel efficient vehicles. Fortunately, the government is at least moving in the right direction in these areas, even if only by stealth.