We are over half way through summer in the southern hemisphere and whilst we have battled heat waves and bush fires, our neighbours in the north have waged war on snow, ice and freezing temperatures. Both extremes can - and do - kill.
The media and climate scientists regularly report that climate change is putting us in serious trouble, with one recent news headline declaring Deadly mix of heatwaves and humidity could make some Australian cities virtually ‘uninhabitable’.
This story reported that heatwave records had been smashed that week (27 November 2017), as many Australian cities experienced above normal temperatures, with surface temperatures in Darwin’s CBD reaching 70 degrees Celsius. The main cause for this huge spike being the urban heat island (UHI) effect, where materials used to build our cities actually help increase temperatures.
Important research lead by people like UNSW’s Professor Mattheos Santamouris, is looking at counteractive measures to UHI from the best materials to reflect urban heat to the best technology and urban design to keep us cool.
For example, in a recent study entitled Cooling Western Sydney, undertaken in conjunction with Sydney Water, Santamouris’ team looked at how water technology can be used to keep city temperatures down. They found that by installing more water features, such as public fountains, ponds and mist, mortality rates during heatwaves could be reduced by almost 50 per cent.
In the same way as water can help keep us cooler, so can trees and other vegetation, as a recent study on Nigerian cities found. Here, the researchers showed that the air temperature was higher and stayed higher for longer inside a building without vegetation as opposed to one with vegetation, proving we already have natural means to control urban temperatures. More importantly, trees and plants produce oxygen, so it is only logical that alongside our concrete jungles, we need natural jungles to counteract our urban expansion.
In terms of physical materials, using reflective or light coloured surfaces in heat affected cities instead of dark is a way of keeping surface temperatures down, and where natural shade from vegetation is impossible, man-made shade can be used instead.
For climates that are cold, it is the other way round. They need urban design to create ways to reduce wind chill and increase exposure to sunlight or access to a building’s internal heat. Snow can also be a tool to block wind and preserve heat. It all goes back to urban design and using the tools and knowledge we already have.
In Australia, where we need policy changes to urban planning and development to help such design measures become law, this will come step by step – but, hopefully, sooner rather than later.
Overall, reducing our carbon footprint is high on the world’s political and environmental agenda, but this is a hard task to achieve, particularly as populations and cities continue to expand all in the name of building future economies. As the world’s population and infrastructure expands, our carbon output will increase, so using counteractive measures such as producing more oxygen and reducing the effects of heat and cold through smarter design and better technology, is the only way to accommodate the world’s current growth.
A documentary recently aired on SBS called Man Made Planet, reflects on our human progress on Earth from space since the first pictures were taken by astronauts. The documentary clearly illustrates the Earth’s transformation over the past 45 years, reporting that during that time the population has doubled to 7.4 billion and as third world countries seek to become first world, the demand for electricity, land for food production (which has tripled) and the world’s overall urban expansion is having a major impact. This is making it increasingly harder to create a ‘low carbon’ world, unless we act smarter.
Some would argue that we need to put a cap on population growth, but this is currently unlikely with the rights of humans to procreate being a leading argument against such an approach.
As we need more energy to live, the importance of research to developing alternative energy sources, such as solar energy producing windows, which could be used in buildings to add power to the grid for our heating and air conditioning, is imperative. There are many technologies in the pipeline and as we progress more will be achieved, but it all takes time.
What we can do now, with the technology and insights we currently have, is make our cities, where the majority live, smarter, healthier and increasingly more liveable.