Seaports have a special need to look ahead, assess their risks and begin adapting to climate change. Scientists project that events such as Superstorm Sandy, Hurricane Katrina and Super Typhoon Haiyan could become more frequent as oceans warm. It is much more certain that global sea levels will rise every decade as glaciers and ice sheets continue to melt, possibly raising water levels by as much as two feet by 2050. Major storms, extreme tides and sea level rise can all pile on top of each other, and planners must consider a worst-case scenario when sea levels are high and a major storm hits at extreme tide. Though tides recede in hours and storm surge recedes in days, sea level will not go down for centuries. Like the proverbial tortoise that wins the race, rising seas will eventually have a much greater impact than the other two issues. Over the last hundred years, the global average sea level rose about eight inches, mostly due to thermal expansion as seawater warmed (although locations vary widely due to local factors). Geologists know that average ocean levels cycle up and down by about 350 feet roughly every 100,000 years, yet without even considering the worst-case scenarios, the latest projections show global average sea levels potentially rising as much as six feet this century. This is primarily due to the melting of glaciers and the Greenland ice sheet.
The need for action
Yesterday’s sea levels and storm patterns served as the benchmark for designing most coastal infrastructure. Developers built ports based on historical conditions that changed little in the last few millennia. However, as environmental conditions change, many ports will find themselves exposed to rising risk levels. Ports already have strong incentives to build for resilience, as storms result in operational delays and huge costs from damage and cleanup. Worse yet, shippers forced to find alternate supply routes may never return. In our recent survey, to which many American Association of Port Authority members contributed, 80% of port operators said that the industry needs to address climate change challenges head on. Fundamentally, these challenges require those involved with ports and harbours to consider new planning time horizons. Often, five to ten years constitutes long-term planning. Yet basic port infrastructure usually lasts half a century or longer. With the realisation that environmental conditions in three or four decades will be quite different, the financial community is starting to ask questions about long-term coastal vulnerability, risk, and the security for their debt. To get a good return on investment, planning today must look beyond the finance and amortisation