An international group of ecologists suggests that cities could be 'laboratories' for examining climate change and its effect on the environment.

Writing in a special issue of Science magazine, devoted to the theme Cities, the ecologists from Australia’s CSIRO, Arizona State University and the New Zealand Centre for Ecological Economics say urban environments act as microcosms of the challenges faced globally, which makes them real world laboratories for understanding and responding to change.

Cities Microcosms of Global Changes

Most people think about climate change and protecting the environment from greenhouse gases in relation to the natural environment – rainforests, glaciers, Arctic and Antarctic ice shelfs, low-lying islands, and so on – but CSIRO’s Dr Xuemei Bai, co-author of the paper, says we shouldn’t ignore cities.

In fact, she and her colleagues in New Zealand and Arizona say cities are important factors in creating and absorbing changes in land and water use, biodiversity and the climate itself.

And when it comes to thinking about protecting the environment, we should focus more on the role of cities.

Original, effective responses to our urban environments – humanity’s primary home – are urgently needed, and urban ecologists are uniquely placed to take us forward, Dr Bai says.

Dr Bai is Senior Science Leader at CSIRO Sustainable Ecosystems, assessing future pathways towards more sustainable cities, particularly in alternative energy, water, materials and built structures.

“As ecologists, the natural environment has traditionally been our main concern, but cities affect and are affected by changes in climate, land use, water and biodiversity,” she says

“Cities are more than just planned spaces. Planners, engineers and architects should be working with urban ecologists to design, develop and redevelop projects suited to these complex, adapting and evolving environments."

Urban Environmental Evolution

As a researcher in Urban Ecology at the Japanese Center for International Studies in Ecology between1993 and 1998, Dr Bai planned, launched and managed an urban ecosystem restoration project in China, in cooperation with the Chinese Academy of Sciences.

This project was the first demonstration site of urban forest restoration by native tree species in China.

She also developed the concept of Urban Environmental Evolution to study the process and mechanism of urban environmental changes in Asian cities.

Reshaping Cities For a More Sustainable Future

Since moving to Australia, Dr Bai has authored a report for CSIRO on Reshaping Cities For A More Sustainable Future.

The paper examined six urban development models to evaluate their impact on a city's air quality and the exposure of its population to harmful pollutants.

“Because cities are largely designed ecosystems, we have an opportunity to use ecological principles in creating urban living and working spaces, housing developments, open spaces, and aquatic environments that can sustain biodiversity and ecosystem function, while also providing important ecosystem services on which the city's population depends,” Dr Bai says.

Urban Hot Spots Drive Environmental Change

“Urban areas are hot spots that drive environmental change at multiple scales,” the ecologists’ group say in the introduction to their paper in Science, Global Change and the Ecology of Cities.

“Material demands of production and human consumption alter land use and cover, biodiversity, and hydrosystems locally to regionally, and urban waste discharge affects local to global biogeochemical cycles and climate.”

For city dwellers, they point out, global environmental changes can seem to be less important than dramatic changes in the local environment.

Urban ecology integrates natural and social sciences to study these radically altered local environments and their regional and global effects.

“Cities themselves present both the problems and solutions to sustainability challenges of an increasingly urbanized world,” they say.