A new report ranks ten leading world cities on their greenhouse gas emissions. It also examines how and why the emissions differ.
As the report says, over 50% of the world’s population lives in urban areas. Leading cities of the world, global cities, are the places where greenhouse gas emissions really need to be cut. The greenest city from the study is Barcelona and the worst is Denver.
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The study examined a host of factors — “geophysical factors (climate, access to resources, and gateway status) and technical factors (power generation, urban design, and waste processing)” — in order to determine the total GHG emissions for each city.
Electricity
The cities with the highest per capita electricity consumption were Denver (11.49 MWh/cap.) and Toronto (10.04 MWh/cap.) and the city with the lowest was Cape Town (3.49 MWh/cap.). The authors believe Cape Town’s emissions in this sector are so low partly because of a relatively low average household income. Denver and Toronto’s emissions may be very high due to high commercial and industrial contributions and climate.
The order for electricity consumption is: 1-Denver, 2-Toronto, 3-Geneva, 4-NYC, 5-Prague, 6-London, 7-Bangkok, 8-LA, 9-Barcelona, and 10-Cape Town.
Transportation
As has been concluded repeatedly in the US and abroad, this study found that cities with higher density did better in this category. The higher the density, the lower the greenhouse gas emissions from transportation. This is largely due to the fact that more people use public transportation, bike and walk in these cities.
By far, the worst emitters in this category were Denver, LA and Toronto. Bangkok was a bit lower, and Geneva, NYC, Prague, Cape Town, and London were just a step below it. Barcelona was clearly the greenest in this category.
Average income was not a significant factor in this case. Even beyond density, however, cities with higher automobile use were worse than cities with better and more popular public transportation systems.
Total Emissions
The study also took waste and “heating and industrial fuel use” into account to determine total emissions. The authors presented total direct emissions, but also went on to include life-cycle emissions, giving a more accurate picture of the true effect of these cities.
Including life-cycle emissions*, the list is as follows:
1-Denver (24.3)
2-Los Angeles (15.5)
3-Toronto (14.4)
4-New York (12.2)
5-London (10.5)
6-Prague (10.1)
7-Geneva (8.7)
8-Barcelona (4.6)
n/a-Cape Town (11.6 before including life cycle emissions)
n/a-Bangkok (10.7 before including life cycle emissions)
*values in t e CO2/cap.
In the end, climate, population density, energy sources, and automobile use were major factors. Additional factors included average income and cities’ roles as “gateway” cities.
More on Transportation:
Hidden Giant #2: Transportation
Image Credit 1: Paco CT via flickr under a Creative Commons license
Image Credit 2: MorBCN via flickr under a Creative Commons license
Image Credit 3: MorBCN via flickr under a Creative Commons license