Monday, July 31, 2006

Portland, Kyoto, and Kristof

Yesterday Nicholas Kristof of the NY Times repeated what's now become an urban myth, that Portland, Oregon (actually Multnomah County, where it sits) has reduced its greenhouse gas emissions to below 1990 levels. This claim, made by Portland's Office of Sustainable Development (OSD) in 2005, is wrong. Kristof made the same error last July as well. He's not the only one--Google searches show that the error has propogated widely.

Besides numerical errors that Portland's Office of Sustainable Development admitted to, the statement doesn't pass the smell test, it seems to me. Multnomah County's 1990 population was 583,887. By 2004 it was up to 685,950, a 17.5% increase in 14 years. US greenhouse gas emissions were up 16% over the same period of time. Portland's light rail systems and compact development zoning seem fairly minimal measures and unlikely to cancel that increase. What smells even worse is OSD's contention that there was an actual decrease in transportation-related CO2 emissions since 1990. Transportation emissions are typically the largest sector of CO2 emissions.

Multnomah County used gasoline sales as a proxy for CO2 emissions, which doesn't seem very precise considering that (1) gasoline prices fluctuate widely, and (2) car and truck fleet miles per hour vary, and (3) the car/truck ratio has undergone changes over the 14 year period. As the free-market Cascade Policy Institute put it,
Since 1990, Multnomah County gasoline sales have increased by less than 1 percent, despite a huge increase in the number of vehicles registered in the county. The OSD used these fuel sales as a proxy for vehicle miles traveled and concluded that CO2 emissions from automobiles in MC have not increased much over this time period.... Also, the Oregon Department of Transportation estimates that total travel on state-owned highways within MC during the 1990-2004 period increased from 2.70 million vehicle miles traveled (VMT) annually, to 2.99 million VMT, an 11 percent increase.
I looked in to this a little early last month, and was told by the City of Portland's Office of Sustainable Development that the next update to this report would be "summer 2007 at the earliest."

BLEG: Anyone have access to TimesSelect and could send me Kristof's entire column of yesterday?

2 comments:

Anonymous said...

Kristof is a notoriously poor fact-checker. Last year, he bought into the myth that DDT has been banned for use against malaria.

Anonymous said...

Now Portland claims they are at 1990 levels again... I wonder if they ever addressed the faulty vehicle emissions methodology? http://www.portlandonline.com/osd/index.cfm?c=41896