Adaptive decision-making: “There are lots of possible futures”

We can’t completely predict climate change, in part because it depends on how we react to it

December 2018

Words by Tony Whitehead

Rendering of Da Nang City Center Square in Vietnam with permeable paving
Minimizing stormwater runoff was one of the primary aims of HUNI Architectes’ competition-winning design for Da Nang City Center Square in Vietnam. It includes permeable paving and trees planted in large rainwater-collecting pits. Visualization: HUNI Architectes

“It’s no use preparing for one probable future,” says Iain White, professor of environmental planning at the University of Waikato in New Zealand. “It’s better to think of the future not as a destination, but a pathway — one best navigated with small, nimble steps.”

White’s research has explored the vulnerability of New Zealand’s water infrastructure to climate change, and he is the author of Water and the City, a book about the relationship between urban areas and the water sources they rely on. However, it is in the business of planning for an uncertain future, the subject of his 2016 TEDx talk, where White is becoming more globally recognized. “Understandably, decision makers don’t like uncertainty,” he says. “There’s this idea, rooted in the Enlightenment, that if we accumulate sufficient facts we can reach 100% understanding. But with the future, that’s just not the case. We can’t completely predict climate change, in part because it depends on how we react to it. But also because the environment is far too dynamic and complex.” The effects of climate change interact with many other factors, he adds, such as population growth and the movement of people into cities.

This uncertainty means that government, planners and businesses will have to change the way they approach the future. “In the 20th century, planners used historical data to plan for, say, a one-in-100-year flood. But we know that the past is not a good guide to future conditions. The one-in-100-year flood might already be a one-in-20-year event. If you take increased urbanization into account, the impact might be more like one-in-ten-years. We already have an increasing incidence of climate records being broken. So we are moving from a high-confidence decision-making environment to one of low confidence.”

The answer, says White, is adaptive decision-making. “If you make a decision that locks you in for 100 years, then that is a long time, in an uncertain world, to defend that decision. For example, if you build a big flood defence wall, that will encourage development in the protected area, and you are committed to maintaining that protection, pretty much forever. It’s expensive, and all defences eventually meet the event that will make them fail. So a decision that only locks you in for ten years might be better.”

From The Possible, issue 04

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White counsels against the mindset that looks always for failsafe options. “You could build enormous flood defences that might never be needed, and you would have wasted a lot of money. It’s often better to have a design that is ‘safe to fail’ instead.” He gives an example from his home city of Manchester in the UK: “To protect the urban centre, they created areas of river upstream where the banks could be safely breached and the water stored on playing fields.” In due course heavy rains tested the system and it worked. By choosing where the failure occurred, White says, the city was protected at a relatively low cost, allowing for further measures to be taken at a later date. “We have to stay flexible. The one thing we are certain of is change, so we have to change too.”

This article appeared in The Possible issue 04, as part of a longer feature about adapting to climate change

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