That is not what the results suggest, however. Vancouver is the
only city to make the top five in all three categories. Otherwise,
there was no overlap at all among the top five in CO2 and buildings. Los Angeles was the only city other than Vancouver to make the top five
in both CO2 and energy, and San Francisco was the only city other than
Vancouver to make the top five in both energy and buildings.
Here's a likely reason why: Although the CO2 scoring considered
carbon emissions per unit of GDP and per person (both valid measures),
the "energy" scoring looked only at electricity consumption as a
quantitative measure, leaving out natural gas and vehicle fuels (both
carbon emitters) among sources of energy. The quantitative "building"
scoring, for its part, was based only on the number of LEED-certified
buildings per capita. Given that certified buildings remain a small
fraction of overall buildings in all cities, this was more an
indication of policy or aspiration than of environmental performance. In addition, two-thirds of the "building" ratings were based on
qualitative evaluations of policy measures. (Subjective policy
evaluations composed a third of the scores for CO2 and energy.)
So I suggest taking some grains of salt, as they say, with these results:
- CO2 top five: Vancouver, Miami, New York City, Los Angeles, Ottawa.
- Energy top five: Denver, Boston, San Francisco, Vancouver, Los Angeles/Toronto (tie).
- Buildings top five: Seattle, San Francisco, Washington, Pittsburgh, Vancouver.
I am very surprised to see Miami and Los Angeles in the top five for
CO2, considering the amount of transportation emissions generated in
report doesn't explain L.A.'s high rating other than with respect to
policy, but notes that its CO2 performance has improved further since
2002, when the study's comparative CO2 data were collected. Miami's
good performance is attributed to a lack of industry in the city and
reliance on newer, more efficient power plants than used by other
Among global comparisons, the report states that the 22 U.S. cities in
the study, on average, emit approximately twice as much CO2 per person
as the five Canadian cities in the study, as well as over three times
as much CO2 as European cities, and approximately four times as much as
Asian cities studied in similar Siemens-sponsored research.
This category measured water consumption per capita (important, but
an order of magnitude more important in arid regions), "share of
non-revenue water shortage leakages," and subjective evaluations with
respect to policies to protect a city's "main water sources" and
Maybe they were hampered by a lack of data sources, but this looks
like a particularly weak evaluation to me. Wouldn't it be more
relevant to measure drinking water purity or pollutant loads in city
waterways? Wouldn't water consumption be more relevant if expressed in
ratio to levels of precipitation?
- Top five: Calgary, Boston, New York City, Minneapolis, San Francisco.
- Bottom dwellers: Detroit, Montreal, Cleveland, Washington, Philadelphia.