Climate adaptation: Adding to a tide of worry

Alexandria4 November 2010

Coastal cities worldwide struggle to slot climate impact into a lengthy catalog of worries. 'Cities are totally unable to deal with this extra level of complexity.'

Sidebars

Bend rather than break: An alternative to armoring cities?

Facing a rising sea, and wondering how far to step back.

by Douglas Fischer

Daily Climate editor

ROTTERDAM, Netherlands - The city of Alexandria, Egypt's second largest, spills down either side of a thin ridge running some 100 kilometers along the Mediterranean coast, hard up against the sea on one side and marsh and reclaimed fields on the other. 

Generally, and especially in the developing world, cities are totally unable to deal with this extra level of complexity generated by climate change impacts. 
- Anthony Bigio, World Bank

It is an ancient port city, never designed for the car, and traffic congestion has long been the city's bane.

So a few years ago, gridlocked and desperate, the city paved over some of its beaches and ran a six-lane highway for 25 kilometers along the Mediterranean shore. 

The corniche was hailed as a solution when it opened in 2006. But that salvation has exposed the city to a second problem: It changed the slope of the sea bottom, worsening erosion and storm surges.

As sea levels rise and storm surges increase in response to a changing climate, Alexandria is finding that a solution to one problem has inadvertently opened the city to others. Nor is Alexandria alone. 

Around the world, low-lying cities are facing unexpected challenges that threaten to chew through scarce or non-existent cash and leave residents and property increasingly vulnerable. 

Protecting those residents from rising oceans and surging water remains one of the more daunting challenges presented by climate change, many engineers and urban planners say. It could also be one of the most expensive.

Last month 1,100 delegates from 62 countries gathered here in Europe's largest port to assess how to best adapt to the threat climate change poses to the world's delta cities. The task is daunting.

Overall, some $70 billion to $100 billion a year - 0.2 percent of global gross domestic product - will be needed to adequately protect cities throughout the developing world, Dutch Crown Prince Willem Alexander noted as he opened the conference, sponsored by the Dutch Knowledge for Climate research program.

Half the world's population lives in a city today; by 2050 upwards of 70 percent of humanity are expected to live in a city either near the coast or in or near one of the world's major river deltas. Those cities are confronted with overcrowding and development issues, aging infrastructure, health and social problems. Climate change layers an entire dimension of complexity atop all that, experts warn.

A need to armor cities

"If you look at what Alexandria had to do to keep functioning, the corniche was perceived as a step forward," said Anthony Bigio, an urban specialist with the World Bank. "But the actions they've taken so far have actually worsened their vulnerability" to climate change.

mekong-600In Vietnam's Mekong Delta, rising seas threaten to bring "extreme salinity" to 45 percent of the country's chief rice-growing region, said Nguyen Thai Lai, Vietnam's vice minister for natural resources and the environment. Falling crop productivity and impaired freshwater supplies, he added, would leave 22 million Vietnamese reeling and could erase 10 percent of the country's economy.

The Dutch know a thing or two about armoring cities against the sea. Some 44 percent of the Netherlands dikes should withstand a 1-in-10,000-year storm - about as high as standards get in the engineering world, according to Piet Dircke, a professor of urban water studies at Rotterdam University of Applied Sciences. Maintaining that levee network requires an annual investment of between $1.3 billion to $2 billion, with no end in sight, he said.

"Once you start living behind dikes, where your wealth is growing, where your safety is dependent, you can never stop doing repair work," said Dircke, who is also water program director at Arcadis, one of the world's leading engineering firms working on urban adaptation efforts. 

It's easy to address the physical climate threat in a way that will not in any way address the social issues. 
- Malcolm Smith, ARUP

In contrast, the United States is spending $15 billion to lift New Orleans' levees to a 1-in-100-year-storm standard by next year's hurricane season. Floodwaters killed 1,886 people and left 80 percent of the city underwater when Hurricane Katrina swept over the city's inadequate defenses five years ago. 

The city's aim is to eventually be protected against a direct hit by a Category 5 hurricane; Katrina made landfall as a Category 3 storm. 

"Where we will be next year is a great place to be compared to where we were," said New Orleans vice mayor Cedric Grant. "But we won't feel comfortable until we get to the next level."

Flash points for conflict

Within this discussion of armor, dikes and defenses, however, runs a larger debate about social equity. As cities confront rising and increasingly hostile waters, questions about how land is developed and transferred, who benefits and who does not will increasingly become flash points for civil conflict. That point, some urban planners say, is often overlooked.

Take India's financial center, Mumbai, as example.

The city juxtaposes some of the wealthiest acreage on Earth with some of the globe's most densely populated and poorest inhabitants. Upwards of 27,200 people per square kilometer pack into informal settlements and slums surrounding the city center, according to official estimates; other sources say the true population density is 16 percent to 25 percent higher.

Protecting the wealthy, who sit isolated on a peninsula, is fairly easy and straightforward from an engineering perspective, noted Malcolm Smith, leader of global master-planning and urban design at ARUP, a global design firm. But what about the millions living outside the high-rent districts?

"It's easy to address the physical climate threat in a way that will not in any way address the social issues," he said.

In Indonesia, adaptation offers a chance to address both issues. Sea-level rise has resurrected calls to move the country's capital from Jakarta, a congested city of 9.8 million plagued by overcrowding, flooding and subsidence.

Jakarta has spent $1 billion on flooding-related problems in the past year, with that figure rising to $16 billion a year by 2050, according to government statistics. At the same time, relocating the capital could reduce the city's burden to provide infrastructure and services and help rework city development, Sonny Keraf, Indonesia's environment minister from 1999 to 2001 and now a university professor, told Reuters recently.

'Water in my living room'chennai-400

At the World Bank, Bigio is spearheading a $1.2 million effort to help three North African cities - Alexandria, Tunis and Casablanca - assess their vulnerability and prepare for climate change.

Given the social and financial stresses confronting those cities, Bigio was initially skeptical any local officials would be eager to talk about the impact of climate change.

He found instead a sense of alarm. 

Both Tunis and Casablanca have been hit hard in recent years by episodes of extreme rainfall that had city leaders fearful of what may be in store, given that climate models predict harder and more intense storms and that coastal erosion is already unfolding at a fast pace. To see such concrete manifestation of that future so soon was surprising.

"The city manager of Tunis is saying, 'Look, I've got water in my living room,' " Bigio said. "It got them thinking that they probably had to revise their whole flood management system."

To be sure, Bigio added, cities in developing countries are already vulnerable to any number of problems. Earthquakes and inadequate building codes, for instance, likely pose a bigger threat to Tunis than the loss of life due to longer heat waves associated with climate change; traffic was far more crippling to Alexandria than the infrequent storm surge.

Climate impact, Bigio has come to understand, adds a variable that most cities simply cannot handle. The issue offers entities such as the World Bank an avenue to discuss important policy decisions - such as upgrading the local storm-water system. But many cities have limited ability to deal with new challenges.

Alexandria, for instance, might have been better off if city engineers had looked at more models and crunched more data before building the corniche.

But, said Bigio, "it's much more difficult than that. The trade-offs between keeping the city functioning and defending against coastal erosion and trying to do it right - one can understand what was pushing them to create that urban highway."

"Generally, and especially in the developing world, cities are still totally unable to deal with this extra level of complexity generated by climate change impacts."

DailyClimate.org editor Douglas Fischer's trip to the Netherlands was paid for by the Dutch trade ministry. 

Photo credits, from top: Alexandria's Corniche courtesy Francisco Anzola/flickr; Mekong Delta courtesy Jon Matthais/flickr; Chennai downpour courtesy Pandiyan V/flickr.

DailyClimate.org is a nonprofit news service covering climate change.

 Find more Daily Climate stories in the TDC Newsroom

Creative Commons License

 This work by The Daily Climate is licensed under a Creative Commons Attribution-No Derivative Works 3.0 United States License.

 Based on a work at www.dailyclimate.org