Cities can reduce greenhouse gas emissions by 70 percent

Feb 12, 2013

Cities around the world can significantly reduce greenhouse gas (GHG) emissions by implementing aggressive but practical policy changes, says a new study by University of Toronto Civil Engineering Professor Chris Kennedy and World Bank climate change specialist Lorraine Sugar, one of Kennedy's former students.

Kennedy and Sugar make the claim in 'A low carbon infrastructure plan for Toronto, Canada,' published in the latest issue of The Canadian Journal of Civil Engineering. The paper aims to show how cities can make a positive difference using realistic, achievable steps. Their research shows that it is technically possible for cities to reduce their emissions by 70 per cent or more in the long-term.

"This is the sort of reduction the international community is calling for, so we can avoid the potentially serious consequences of ," said Professor Kennedy.

They note that more than half of the world's population lives in urban areas and over 70 per cent of global can be attributed to cities. "Cities are where people live, where economic activity flourishes," said Sugar. "Cities are where local actions can have global impact."

The study focuses on buildings, and transportation. Best practices as well as options and opportunities – for example, encouraging and increasing bicycling infrastructure – are detailed.

"It is possible for a Canadian city, in this case Toronto, to reduce its GHG emissions by the sort of magnitudes that the international scientific community have indicated are necessary globally to keep global temperature rise below 2 C," Kennedy and Sugar write.

"With current policies, especially cleaning of the , Toronto's per-capita GHG emissions could be reduced by 30 per cent over the next 20 years. To go further, however, reducing emissions in the order of 70 per cent, would require significant retrofitting of the building stock, utilization of renewable heating and cooling systems, and the complete proliferation of electric, or other low carbon, automobiles."

The biggest obstacle is the city's building stock, according to Kennedy. Buildings have a lifespan measured in decades, so it takes time to replace older buildings with more energy-efficient ones.

The study arose out of a handbook Kennedy and his students produced for the Toronto and Region Conservation Authority in 2010, Getting to Carbon Neutral: A Guide for Canadian Municipalities. In the current paper, he and Sugar wanted to demonstrate how cities could achieve measurable results by adopting the policies outlined in the guide.

Kennedy, author of The Evolution of Great World Cities: Urban Wealth and Economic Growth (2011), teaches a course on the design of infrastructure for sustainable cities. He has consulted for the World Bank, the United Nations and the OECD on urban environment issues.

Explore further: Solar energy-driven process could revolutionize oil sands tailings reclamation

add to favorites email to friend print save as pdf

Related Stories

Predicting a low carbon future for Toronto

Feb 06, 2013

Cities are major players in the climate change game. More than half of the world's population lives in urban areas and over 70% of global GHG (greenhouse gas) emissions can be attributed to cities. A case study of Toronto ...

Urban metabolism for the urban century

Jan 24, 2013

Like organisms, cities need energy, water, and nutrients, and they need to dispose of wastes and byproducts in ways that are viable and sustainable over the long run. This notion of "urban metabolism" is a model for looking ...

Big cities are not always biggest polluters

Jan 26, 2011

Big cities like New York, London and Shanghai send less pollution into the atmosphere per capita than places like Denver and Rotterdam, said a study released Tuesday.

Recommended for you

Big changes in the Sargasso Sea

11 hours ago

Over one thousand miles wide and three thousand miles long, the Sargasso Sea occupies almost two thirds of the North Atlantic Ocean. Within the sea, circling ocean currents accumulate mats of Sargassum seawee ...

Water-quality trading can reduce river pollution

11 hours ago

Allowing polluters to buy, sell or trade water-quality credits could significantly reduce pollution in river basins and estuaries faster and at lower cost than requiring the facilities to meet compliance costs on their own, ...

Managing land into the future

15 hours ago

Food production is the backbone of New Zealand's economy—and a computer modelling programme designed by a Victoria University of Wellington academic is helping ensure that farming practices here and overseas ...

User comments : 0