Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Suburban sprawl cancels carbon footprint savings of dense urban cores

07.01.2014
Interactive maps of US metro areas shows striking differences between cities and suburbs

According to a new study by researchers at the University of California, Berkeley, population-dense cities contribute less greenhouse gas emissions per person than other areas of the country, but these cities' extensive suburbs essentially wipe out the climate benefits.


A CoolClimate Map of New York City's carbon footprint by zipcode tabulation area shows a pattern typical of large metropolitan areas: a small footprint in the urban core but a large footprint in surrounding suburbs.

Credit: Daniel Kammen and Christopher Jones, UC Berkeley

Dominated by emissions from cars, trucks and other forms of transportation, suburbs account for about 50 percent of all household emissions – largely carbon dioxide – in United States.

The study, which has been accepted for publication in the journal Environmental Science & Technology (ES&T), uses local census, weather and other data – 37 variables in total – to approximate greenhouse gas emissions resulting from the energy, transportation, food, goods and services consumed by U.S. households, so-called household carbon footprints.

Interactive carbon footprint maps for more than 31,000 U.S. zip codes in all 50 states are available online at http://coolclimate.berkeley.edu/maps.

"The goal of the project is to help cities better understand the primary drivers of household carbon footprints in each location," said Daniel Kammen, Class of 1935 Distinguished Professor of Energy in the Energy and Resources Group and the Goldman School of Public Policy, and director of the Renewable and Appropriate Energy Laboratory. "We hope cities will use this information to begin to create highly tailored, community-scale climate action plans."

A key finding of the UC Berkeley study is that suburbs account for half of all household greenhouse gas emissions, even though they account for less than half the population. The average carbon footprint of households living in the center of large, population-dense urban cities is about 50 percent below average, while households in distant suburbs are up to twice the average: a factor of four difference between lowest and highest locations.

"Metropolitan areas look like carbon footprint hurricanes, with dark green, low-carbon urban cores surrounded by red, high-carbon suburbs," said Christopher Jones, a doctoral student working with Kammen in the Energy and Resources Group. "Unfortunately, while the most populous metropolitan areas tend to have the lowest carbon footprint centers, they also tend to have the most extensive high carbon footprint suburbs."

Taking into account the impact of all urban and suburban residents, large metropolitan areas have a slightly higher average carbon footprint than smaller metro areas.

Developing sustainable cities

"A number of cities nationwide have developed exceptionally interesting and thoughtful sustainability plans, many of them very innovative," Kammen said. "The challenge, however, is to reduce overall emissions. Chris and I wanted to determine analytically and present in a visually striking way the impacts and interactions of our energy, transportation, land use, shopping, and other choices. Cities are not islands: they exist in a complex landscape that we need to understand better both theoretically and empirically."

The UC Berkeley researchers found that the primary drivers of carbon footprints are household income, vehicle ownership and home size, all of which are considerably higher in suburbs. Other important factors include population density, the carbon-intensity of electricity production, energy prices and weather.

"Cities need information on which actions have the highest potential to reduce greenhouse gas emissions in their communities," explained Kammen. "There is no one-size-fits-all solution."

Efforts to increase population density, for example, appear not to be a very effective strategy locally for reducing emissions. A 10-fold increase in population density in central cities yields only a 25% reduction in greenhouse gas emissions.

"That would require a really extraordinary transformation for very little benefit, and high carbon suburbanization would result as a side effect," Jones said.

Increasing population density in suburbs appears to be an even a worse strategy, he said. Surprisingly, population dense suburbs have significantly higher carbon footprints than less dense suburbs.

"Population dense suburbs also tend to create their own suburbs, which is bad news for the climate," explains Jones.

So if building more population-dense cities is not a viable solution for city planners, what is? The project website includes a tool that calculates carbon footprints for essentially every populated U.S. zip code, city, county and U.S. state (31,531 zip codes, 10,093 cities and towns, 3,124 counties, 276 metropolitan regions and 50 states) as well as an interactive online map allowing users to zoom in and out of different locations. Households and cities can calculate their own carbon footprints to see how they compare to their neighbors and create customized climate action plan from over 40 mitigation options.

In some locations, motor vehicles are the largest source of emissions, while in other locations it might be electricity, food, or goods and services. California, for example, has relatively low emissions associated with household electricity, but large emissions from transportation. The opposite is true in parts of the Midwest, where electricity is produced largely from coal.

Tailored emission lowering strategies

The real opportunity, say the authors, is tailoring climate solutions to demographically similar populations within locations.

"Suburbs are excellent candidates for a combination of solar photovoltaic systems, electric vehicles and energy-efficient technologies," said Kammen. "When you package low carbon technologies together you find real financial savings and big social and environmental benefits."

The authors argue that cities need to step out of traditional roles in planning urban infrastructure and learn how to better understand the needs of residents in order to craft policies and programs that enable the adoption of energy and carbon-efficient technologies and practices.

One example of this is the CoolCalifornia Challenge, a statewide carbon footprint reduction competition to name the "Coolest California City." The program, run by Jones and Kammen and sponsored by the California Air Resources Board and Energy Upgrade California, will be accepting applications for new cities in February. Each city creates their own, targeted strategies to reduce barriers and increase motivation to engage residents in climate action.

"People need to act within their own spheres of influence, where they feel they can make the most difference," Jones said. "We hope the information provided in these tools will help individuals, organization and cities understand what makes the most impact locally and to enable more tailored climate strategies.

The research was funded by the National Science Foundation and the California Air Resources Board.

Robert Sanders | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>