Those living in big cities will find it especially difficult to escape the heat right now.
Manchester University researchers, funded by the Economic & Social Research Council (ESRC), have shown how architects and planners can work with scientists to minimise the effects of urban heat. Local climate patterns can be mapped and analysed and the air can be cooled where appropriate with vegetation and porous paving. Buildings can be aligned with open spaces to encourage land and sea breezes to flow freely for ventilation.
This is needed because buildings trap radiation and disturb the airflow of the winds. Impermeable city surfaces repel moisture, while dense construction materials store heat. Machine and human activity adds warmth, dust and pollution. Air-conditioning units may cool the inside of buildings but they increase temperature levels outside. While the countryside freely radiates its daily heat after dusk, urban surfaces retain heat long into the night, leading to what is called an ‘urban heat island’. The difference between urban and rural temperatures can be as much as 10˚C.
The authors of the study, Professor Michael Hebbert and Dr Vladimir Jankovic, found that despite all the technology available, most planners build cities totally oblivious to the atmospheric effects they are creating.
"The need for this awareness will increase as the effects of global climate change become more pronounced, bringing more extreme fluctuations of temperature, and risks of flooding not only from rivers and rising sea level, but also from downpours that overwhelm urban storm drains and sewers," said Professor Hebbert.
"Cities which understand and manage their local climate have a head start in responding to global climate change."