How to Decrease Emissions

Americans responded to the economic crisis and rising oil prices in 2008 by driving less and purchasing fuel-efficient cars. Michael Sivak and Brandon Schoettle have looked at the effect of these trends on carbon dioxide emissions between October 2007 and April 2009. The authors found that “carbon dioxide emissions per driver from purchased new vehicles were lower in each month compared to October 2007.” The greatest decrease was in July 2008, when emissions were 12 percent lower than in October 2007. April 2009 emissions were 8 percent lower than in October 2007. Seems like higher gas prices do a pretty good job of decreasing emissions. [%comments]

Bram Fokke

This is surprising how? In Europe, gas prices have been higher for years and consequently we drive cars that are more fuel-efficient.


I seem to recall them doing a pretty good job destroying the economy too.


This preseumes that fuel efficient care are not purchased for some reason other than gas prices. Maybe people are buying more fuel efficient cars because they see them putting out less emissions.

If gas prices were the only determining factor it would mean that if a fuel efficent car could be made that actualy polluted more than gas guzzlers, people would still buy it at the same rate they buy gas guzzlers.


I wonder what the increase in crash fatalities was from driving the smaller cars, and how that same number was impacted in the positive due to increased prices.

Jens F!

In Denmark the price of gas is currently around 7 US$ per gallon. This has mainly been done in the name of saving fuel. According to the Statistics Denmark [1], the national statistics bureau, new cars bought in 2008 in DK on average drives 42.3 MPG (18 km/l). Does anyone know comparable numbers from other locations with lower or no tax on gas?

Cars are also taxed quite high, up to 250% (including sales tax). This makes expensive cars (with low MPG) even more expensive.

To even up for these high taxes you get a tax cut depending on how far you live from where you work. You get the same tax cut if you bike, take public transportation, drive a fuel efficient car or a big SUV. This would seem like an easy way to give people incentive to use a cheaper means of transportation, with the hope that cheap means greener.


Another David

@aubrey: high gas prices were not the culprit in destroying the economy. if they were, the problem would have been fixed when gas prices went down. did they help fix the situation that had already begun to unfold? "no" would be the understatement of the year. but they were not the cause.


@charles: The impact on fatalities was quite probably negative: First, because the decrease in emission is mostly due to driving less rather than buying new smaller cars. Second, the heavier a car is, the deadlier it is usually in traffic (to simplify: if a 3-ton SUV hits you head-on, you die; if a Smartcar hits you, you don't).


Driving peaked before emissions. More like July or August 07.

Fuel economy declined along with rising prices from 2005 (driving was pretty much flat from 2005 to the end of 2007), up until mid 08, when driving really dropped off.

David, rising input cost sincrease risk and cause uncertainty, falling prices do not increase certainty. Rising fuel prices also drive up other prices. That is why fuel price increase decrease consuption by more than the increased fuel cost and also why decreases in price don't increase consumption. Declines in fuel do not increase certainty in consumers. See oil shock writings by James Hamilton out of UofC, San Diego.