Toronto has joined Arup’s Global Sponge Cities Snapshot – a global survey of the natural ability of cities to absorb rainfall. The survey has shown that the urban center of Toronto is far ahead of Sydney and London in terms of its “sponginess,” with its sponge rating of 30% (compared to 18% for Sydney and 22 % for London). Toronto obtained the same sponginess rating as New York, Mumbai, and Singapore.
Arup, a global sustainable development consultancy, developed the snapshot to prompt cities to ask: how spongy am I? The authors of the survey are calling on leaders to move beyond concrete interventions and instead look to nature for solutions to climate-related challenges, such as managing heavy rainfall.
Authors have studied sample areas of approximately 150km2 in ten diverse global cities with Toronto joining Auckland, London, Montreal, Mumbai, Nairobi, New York, Shanghai, Singapore, Sydney – to assess how well their existing natural infrastructure helps them absorb rainfall.
This analysis comes as the IPCC predicts that water-related risks will increase with every degree of global warming, with around 700 million people currently living in regions where maximum daily rainfall has increased.