“Global floods and extreme rainfall have increased by over 50% in the past 10 years
as a result of climate change...”
Over the past decade, the costs of extreme weather events have reached $227 billion per
year, up 61% from the previous decade.
By 2050, the global cost of rising seas and flooding could increase to $1 trillion.
And the human effects of these events are
most heavily concentrated in cities.
90% of cities are located on coastlines.
As cities swell, the use of impervious construction materials - metal, concrete and asphalt - is
causing the natural flood defences from soil to be lost. These materials literally create
a barrier, preventing the ground below from absorbing rainwater.
But here in China, where urban flooding has
been a major issue, a solution is being rolled out - Sponge Cities.
Sponge Cities are exactly what they sound like. Cities built with infrastructure like
porous roads that absorb water and cool the environment. Plant covered rooftops for water
collection and recycling, and urban wetlands that detain and filter water.
Companies like Suez, based in France and Arcadis in the Netherlands are helping Chinese cities
to re-use up to 70% of rainwater - making excess water work for the city rather than
destroy it.
As more cities struggle to face the challenge of changing weather conditions, these techniques
will be in strong demand. In Europe, Berlin is already implementing
the sponge city concept. Others are likely to follow.
At present, only 5% of climate change investment is spent on adaptation activities. But investing
$1.8 trillion in key areas of focus would accrue benefits of more than $7 trillion,
a four-to-one return.
The opportunities are crystal clear.