Washington, May 8 : Economists have suggested that increasing the prices of gasoline could lead to a dramatic saving in US greenhouse-gas emissions.
According to economists from the University of California, Davis, high fuel prices are turning consumers off SUVs and onto smaller, more fuel-efficient vehicles.
Also, if the fuels get expensive, car owners are predicted to cut back on driving in order to save money.
The changes are being driven by record fuel prices in the US, where, at the end of April, the average price of gasoline stood at 3.65 dollars per gallon, 20 per cent more than in January and treble the price of a decade ago.
Until recently, these increases did not seem to be having a consistent effect on the car market and fuel use.
Though sales of SUVs in the US have been falling over the past few years, this decline has come on the back of years of rapid growth, and overall gasoline consumption has been increasing every year since 1991.
That could be about to change.
Knittel and colleagues looked at data on 1.4 million car purchases over the past 10 years, comparing sales patterns with gas prices.
They found that sales of the least fuel-efficient cars, such as SUVs and pick-up trucks, fell by 13 per cent for every 1 dollar per gallon increase in the price of gasoline. The biggest SUVs suffered the most, with sales dropping by over 25 per cent for every dollar by which the gas price rose.
For every 1 dollar hike in gas prices, there was a corresponding 17 per cent sales boost for the most efficient vehicles, such as compact cars and hybrids.
According to Knittel, over about a decade, such changes in buying habits could cut the amount of gasoline used by US drivers by around 7 per cent for every 1 dollar increase in its price.
Knittel's findings are in broad agreement with those of economist Kenneth Small of the University of California, Irvine, who looked at data on US fuel consumption and prices over the past 40 years.
Small projected last year that the recent doubling in fuel prices would quickly lead to a 4 per cent drop in the total mileage covered on the roads.
In the longer term, as drivers continue to react to rising prices, he projects the size of the reduction will grow to around 20 per cent.
This in turn would lead to a substantial reduction in carbon emissions, almost tens of millions of tonnes of CO2 per year, equivalent to roughly 2 per cent of the country's greenhouse-gas emissions for 2006.