Build Parks to Climate Proof Our Cities
====================================================================================
original post:
http://www.eurekalert.org/pub_releases/2007-05/uom-pt051407.php

"We discovered that a modest increase of 10% green space reduced surface temperatures in the urban environment by 4C, which would overcome temperature rises caused by global warming over the next 75 years, effectively 'climate proofing' our cities." said Dr Roland Ennos. by Staff Writers
Manchester UK (SPX) May 16, 2007

Scientists looking at the effect global warming will have on our major cities say a modest increase in the number of urban parks and street trees could offset decades of predicted temperature rises. The University of Manchester study has calculated that a mere 10% increase in the amount of green space in built-up centers would reduce urban surface temperatures by as much as 4C.

This 4C drop in temperature, which is equivalent to the average predicted rise through global warming by the 2080s, is caused by the cooling effect of water as it evaporates into the air from leaves and vegetation through a process called transpiration.

"Green space collects and retains water much better than the built environment," explained Dr Roland Ennos, a biomechanics expert in Manchester's Faculty of Life Sciences and a lead researcher in the team.

"As this water evaporates from the leaves of plants and trees it cools the surrounding air in a similar way to the cooling effect of perspiration as it evaporates from our skin."

"Urban areas can be up to 12C warmer than more rural surroundings due to the heat given off by buildings, roads and traffic, as well as reduced evaporative cooling, in what is commonly referred to as an 'urban heat island'," said Dr Ennos.

"We discovered that a modest increase of 10% green space reduced surface temperatures in the urban environment by 4C, which would overcome temperature rises caused by global warming over the next 75 years, effectively 'climate proofing' our cities.

Dr Ennos's collaborators in the School of Environment and Development are Professor John Handley, Director of the University's Centre for Urban Regional Ecology (CURE), and Dr Susannah Gill, now based at The Mersey Forest http://www.merseyforest.org.uk/

The research was part of the Adaptation Strategies for Climate Change in the Urban Environment (ASCCUE) project, which is an Engineering and Physical Sciences Research Council (EPSRC)-funded scheme under the wider umbrella 'Building Knowledge for Climate Change' (BKCC).