A new report warns the past four years have been the
hottest on record. Urban planning – including more urban greenery – could limit
the impact of temperature rises on people’s health, if action is taken now.
Today’s World Meteorological Organization report on the
state of the global climate in 2018 says this year is set to be the fourth
hottest since records began. Cities – which will be home to 68% of the world’s
people by 2050 – are particularly vulnerable to global warming.
Cities can trap heat and become ‘urban heat islands’, and
the world’s warming urban areas will put billions of people in danger of
heat-stress. Research shows clever city planning can play a crucial role in
providing cooling solutions. For example by incorporating light-coloured
surfaces, green roofs, as well as better building standards.
Often an overlooked solution, trees and vegetation also play
a vital role in regulating temperature and in reducing dangerous heat stress
for communities in cities. They provide shade, reflect heat, and help cool the
air. Most green space initiatives are not being done
explicitly for cooling reasons – they’re designed to mitigate climate change
boost people’s wellbeing or tackle air pollution. But they will have an
important cooling effect.
Many cities have recognised we’re heading towards a crisis
point and are taking action. India declared the issue a national health
priority after deadly heatwaves in 2010. Now, in cities like Ahmedabad, heat action plans are in place to provide an early-warning system for heat events as
well as advice and support to help people cope with the effects. More support
is needed to replicate these successful initiatives elsewhere.
We’ve examined trends in urban heat management as we prepare
for the next round of Ashden awards, which celebrate radical innovation in
sustainable energy. It is clear that cooling innovators needed more support and
investment to develop their ideas.
The WMO report says this year temperature records were
broken in cities including Helsinki, Lisbon, Riga and Seoul. Other major
heat-related events included droughts in Australia and South America, fatal
heatwaves in France and Japan and exceptionally high temperatures in many parts
of the Middle East and North Africa.