Cities Are Heat Death Traps…. Is There A Way Out?
I bet we are all looking forward to a warm and sunny break from this harsh winter that has consumed our July. I don’t know about you but I am ready to put on my bathers, tan at the beach and swim in the clear ocean with the warmth of the sun glistening on my back.
Though, with summer looming around the corner, we have all forgotten (me included until I started researching) that the recent trends of global warming will make this summer an exceptionally hot one. One that will create a heat death trap in cities around the globe.
The National Oceanic and Atmospheric Administration (NOAA) showed that 2016 was the warmest year on record across the globe. Even dating since as far back as 1880.
Hot sunny Los Angeles City. Image credit: Untitled by jvoves via Flickr
Have You Ever Heard of the Urban Heat Island Effect?
These exceptionally high temperatures can lead to a city death trap as urban areas are usually a lot warmer than rural areas. These extra degrees can turn from uncomfortable to deadly in a matter of hours. This is due to something called the urban heat island effect.
Cities have developed into car-clogged roads, paved asphalt streets and industrial buildings with dark roofs. Vegetation has become sparse and more heat is created through the energy generated by transport, buildings and people. Since cities contain a high density of this so heat is trapped and water cannot evaporate. Combine these two together and you get increased surface temperatures.
Asphalt (which is what most our streets are made from) can absorb up to 90% of the sun’s radiation and warms the air around it.
Remember that time you wore a black t-shirt on a sizzling hot summer day? Did you feel even warmer? Darker clothes absorb heat, warming your body whereas lighter clothes reflect heat, keeping your body cool.
Is There A Solution?
From Australia to the other side of the world in America, councils are getting on board with combatting this issue.
The council of Sydney is testing a lighter-coloured pavement in a few of its streets to reduce temperatures in urban areas. Whilst in Melbourne, the council has started an initiative to plant more vegetation around the CBD.
Meanwhile, Los Angeles is painting its streets white…. that’s right, you heard me. Mayor Eric Garcetti has pledged to reduce the average temperature of the city by 3 degrees over the next 20 years: improving air quality, energy consumption and saving lives.
LA is coating their roads in ‘CoolSeal’, a white-grey paint that is 10 degrees cooler than asphalt. They are also investing in cool roofs, green walls and planting more vegetation around the city.
Green walls in cities, One Central by Ashley via Flickr
Planting Trees > Cool Roofs > Reflective Pavements
However, an interesting fact that has been found is that there is a hierarchy in effectiveness when it comes to applying different adaptation techniques.
If an area has lots of trees, reflective pavements will be a waste as not much sunlight will be able to get past the trees. Though if an area has no trees, planting more vegetation will work more effectively than cool roofs will.
It is important to note that these plans to cool cities won’t compensate for all the consequences of climate change. Though it will help to reduce the death trap that is known as the ‘urban heat island effect’.
More links for interested readers: