Coping with Climate Change: Uncertain, But Not Unprepared

“Hurricane Sandy was a toll paid for procrastination,” claims a recent article in the New York Times. “New York clearly ought to have taken certain steps a while back, no-brainers after the fact.” Similarly, The Economist refers to Hurricane Sandy’s damage as “the costs of New York’s complacency on flooding.” They may be correct; the government was well-informed of the city’s vulnerability. In 2005, flood risk scientist Jeroen Aerts was hired as an advisor to the city. He was shocked. “I was looking at the water and wondering – where are the levees? Nobody was doing anything on flood risk.” Little was done in the seven years since Aerts began his work, even with the near miss of Hurricane Irene in 2011. The obvious question remains: in the face of such glaring exposure, why wasn’t anything done?

This tendency to react rather than prepare is well documented throughout history. The Netherlands and London, now armed with world class flood defense systems, only built their barriers after major disasters. The post-Katrina levees erected around New Orleans are yet another reminder of our natural instinct to react, not prepare. Further, hurricanes rarely venture as far north as Manhattan, so perhaps the city lacked any sense of urgency. But climate change may force New Yorkers to reevaluate what they consider a normal weather pattern.

Even without the complicating factor of climate change, planning disaster risk reduction projects is fraught with difficulty. With lifetimes of 50 to 100 years, flood defense projects require long-term thinking – and decision-makers are not accustomed to thinking beyond the next election. As a result, the “not in my term of office” attitude is frequently taken for costly disaster risk reduction projects with no obvious payoff. After all, a flood defense pays itself back through damages avoided – and “it could have been worse!” is not exactly re-election slogan material. Adding to the complexity, these projects require billions of capital and cooperation among environmental, social, and financial groups.

In an interesting study, decision-makers in London are asked to confront a hypothetical situation in which the West Antarctic ice sheet collapses. Such an event could cause a rapid 5m sea level rise over 100 years. To discover how a threatened city such as London might respond, interviews were conducted with national and local government officials, emergency planners, environment groups, and private sector representatives. The resulting discussion is revealing:


No government works more than 2-3 years ahead.  Politically it would be difficult to see any government taking big, unpopular, decisions.  There would always be questions about probability”

“If you predict this kind of eventuality and make plans for it and it doesn’t materialise you get voted out of office. Would the Government sit on it then, until it is too late?” 

“In order to make decisions you had to be certain about your data, particularly where there was a huge resource commitment.”


In one word, uncertainty. The root cause behind this decision paralysis is uncertainty over the timing, frequency, magnitude, and location of disasters. The prospect of climate change only compounds the confusion. For example, the New York area will likely be affected by rising sea levels and more frequent storm surges. But how quickly will these changes take place, and how drastic will the impact be? Planners risk under-preparedness when catering to the best-case scenario and over-spending if preparing for the worst. This dilemma results in inaction.

Adaptive management provides one possible means of resolving such decision paralysis. In this approach, planners do not commit themselves to the worst-case or best-case scenario. Instead, flexibility is prioritized: an incremental step is taken while preserving the options to do more in the future if appropriate. As time passes, data and knowledge accumulate, and additional decisions can be made with greater certainty. This approach manages our uncertainties – we aren’t idly waiting for disaster to strike, but we are reducing the risk of maladaptation.

The Thames Estuary 2100 plan is one prominent example of adaptive management in flood defenses. Finalized in 2010, it is designed to protect the region from flooding until the next century through an observe-and-adapt approach. For example, walls are built with widened foundations in case they must be heightened later. Land is set aside for new barriers or safeguarded as flood storage zones. Different defense options are developed for the future, but the actual decision point is decades away. All the while, key indicators such as mean sea level, peak surge height, and the value of assets at risk are monitored to guide decisions on what to do and when to do it. Though the financial burden remains heavy, spreading the spending across different time periods alleviates the pressure on one administration to sustain the entire cost. If we plan with foresight and keep our options open, we can harness this paralyzing uncertainty and transform it into action.

Leading climate scientist John Weyant wrote that climate change is “a problem requiring sequential decision-making under uncertainty rather than requiring a large, one-shot, ‘bet-the-planet’ decision.” Embracing this model – and relieving our decision paralysis – will go a long way towards avoiding Sandy-like tolls of procrastination in the future.

  • TDowning

    Nice! I was part of the ‘study’ on extreme sea level rise in London. It was part of an EC project initially posed by Richard Tol as a not unimaginable scenario, with matching studies in The Netherlands and southern France (and published in Climatic Change).

    We inter-acted with the Thames barrier project–involving some of their experts and stakeholders in our interviews and role-playing simulation. Which seemed to have supported the internal move toward adaptive management and consideration of more extreme scenarios than are usually the case. And at a time when the IPCC had ducked the issue of WAIS and Greenland collapse as too uncertain to include in their assessment (this is the AR4). Gratifying to see extreme scenarios becoming more accepted (and based on stronger science).

    Dismaying that the hard institutional lessons are still delayed. But not shocked as this is the reality we start with. Our favourite motto is ‘Uncertainty is the reason for action’. It takes decades to mobilise action, even when certain.

    Tom Downing, Global Climate Adaptation Partnership