Heat Islands
[rating 4.5]
Heat islands have been recognised for many years. One of the first instances would be the First Report of the Royal Commission on Pollution, which reported the impact of urban climate on London (although there have been reports linking it back as far as the early 1800s). Of late, they have gathered some controversy, in a few cases the links have been made to global warming but this is generally seen as tenuous at best. What is far more accepted is the changes that such islands can have on the local area and the impacts this can have (such as increased duration and strength of storms). This book aims to examine this phenomenon and give some way of reducing the impact.
We start with a definition and basic description of the phenomenon. It’s obviously urban but there are other characteristics including heat source (artificial surfaces) and impacts on the boundary layer (c.2000m). From this overview we can tackle more specific areas; the first of which is mechanism. It needs more than just an urban area with numerous studies pointing out other, less obvious requirements including variations in moisture and wind speed. It’s just a step to getting some real data and so we move on to discuss how to measure and model these islands. Heat islands aren’t just a nuisance; they have real economic and environmental impacts. One simple example is taken: roofs. Dark, uninsulated roofs need more energy to cool the living space underneath which pumps more heat into the outside etc. Perhaps easier would be to reduce the need in the first place. So, having argued for the change, the book turns to finding solutions. From here on, it’s a mixture of science, thermal calculations and good urban building design/materials. We start with the roof (go for light colours and pack in insulation) to paving (again light coloured but porous to store water which evaporates and cools!) to trees (natural shade). Two final chapters describe the overall benefits to the community and suggest an action plan to tackle the problem.
The text is US and many of the examples and ideas would relate only to that country. however, the concept is universal and so are the ideas. As a text gathering together a great deal of data on a specific problem, this book is a very useful addition. However, reading through it would have a greater appeal to educators and students. Here’s a text that not only sets out a problem, shows how data are gathered (all good science education) but puts forward solutions (environmental education, citizenship). Furthermore, the solutions are all current and reasonable. This would make a great set of projects for senior students. As such this is a great text that deserves the widest readership.
