+ Cities should adopt a systemic approach to resilience that allows them to fail 'gently' rather than catastrophically.

Those who run the world’s major cities are becoming increasingly aware that they are unable to cope with a number of global or regional scale threats: climate change, pandemics, water shortages, terrorist activity, collapsing fish stocks, to name but a few.

Currently, resilience is based on silo culture: utilities, businesses and the public sector all have their own individual plans for dealing with disaster – a linear approach. City administrations are going to have to completely rethink their approach to resilience. They need to adopt a more systemic approach that allows cities to fail 'gently' rather than catastrophically.

An approach that takes us to systems thinking around city infrastructure – in the broadest sense – would see city planners and managers actually planning for disaster resilience accepting that there will, on occasion, be disaster. I suppose a very simple example would be the flood levies on the Mississippi which were allowed to be breached because they could not actually resist the levels of water in the river.

Similarly, the Wivenhoe dam, upstream of Brisbane, was built in the early 1980s to flood-proof Brisbane following the 1974 floods. The abnormal weather events of December 2010 put the dam in danger of failure. The decision was taken to release water from the dame which exacerbated the situation downstream but prevented a more catastrophic situation occurring.

Arup has been working with Sheffield City Council (UK) on a pilot study to assess the city’s resilience to the effects of climate change. We've sought to understand how climate change affects wider urban systems in Sheffield, such as transport, waste management and food supply. We looked at 15 systems in total, questioning whether they are able to meet the pressures that climate change will place upon them. An important element of this approach is the recognition that the systems do not operate in isolation – they interact. For example, in Sheffield the relationship between employment land and flood risk is of critical importance to the city.

We developed a toolkit to help us identify which systems within the city will be affected by climate change and what the key interdependencies are. Our approach has involved numerous stakeholders through an online survey and workshops and we are now in the process of developing an action plan. The toolkit could be used to assess any city’s resilience to climate change, addressing both infrastructural and institutional factors, in an efficient and joined-up way.

Arup’s focus is on disaster resilience rather than resistance, affording communities – particularly those in vulnerable zones – the chance to recover much more quickly in the aftermath. It requires us to accept that cities will have to face scenarios in which some degree of failure is inevitable.