Adaptive Strategies in Managing Climate Change Risk
With the threat of rising sea level due to thermal expansion (water increases volume as it gets warmer) and melting of land-based ice (such as glaciers and polar ice sheets), coastal cities are planning ways to minimize the impacts of flooding on city infrastructure. The Thames Barrier (pictured) is one such engineering solution. It is located just downtown of central London, and in its stainless steel glory perhaps resembles more a piece of modern art than a storm barrier.
Aesthetics aside, the barrier has – for the past 25 years – successfully protected much of London from dangerously high tides and storm surges. The massive steel gates remain open for most of the year, allowing marine traffic to pass through. They “close” during periods of anomalously high tide and surge, by raising and rotating 180 degrees. Since its inception in 1982, the Barrier has been closed a total of 114 times to protect against flooding. However, it was closed 4 times in the 1980s, 35 times in the 1990s, and 75 times in the 2000s – meaning that 2/3 of the closures have occurred in the past 9 years. With this increase in mind, and projections of rising sea levels, the UK’s Environmental Agency has taken appropriate steps to adapt and manage this risk.
The Thames Estuary 2100 project, dubbed TE 2100, is a comprehensive strategy designed to protect the entire estuary for the next 100 years. As Sarah Lavery, an official from the Environmental Agency, explained at the Lamont-Doherty Earth Observatory during her seminar “A Tale of Two Cities – London and New York Adapting to Climate Change” on May 29, sustainability is at the core of any adaptive approach. Sustainability, as Lavery notes, is more than just meeting the needs of the present with an eye to the future. True sustainability requires action that is expected to be sufficient for the far off future – in this case 100 years.
The TE 2100 relies on cutting-edge predictions generated by the Proudman Oceanographic Laboratory and the Centre for Ecology and Hydrology to reduce the uncertainty surrounding the impact of climate change on flood risk. Using these data, Lavery and her colleagues have produced three distinct scenarios projecting varying degrees of risk. A range of projections was needed to accommodate the complexities of polar ice melt, which could bump the IPCC estimate of sea level rise of 18-59 cm up to 80-150 cm by 2100. Lavery demonstrated – through models of flood risk vs. time – that the TE 2100 can successfully manage all but the absolute worst-case scenario, one that they deem highly unlikely and unexpected.
The implementation of the TE 2100 has multiple, distinct phases, each of which plays a crucial role in mitigating the growing flood risk. These measures include maintaining existing barriers, constructing new ones, and coordinating with local communities and authorities to raise awareness and build resilience. Although it has been in the works since 2002, the TE 2100 will officially be proposed to the government in 2010.
So what does this have to do with New York? London and New York are different cities facing very different threats. They might share a coastal location and low sea level in places, but New York has the Hudson and East River while London is dominated by the Thames; London faces storm surges from weather systems from the Atlantic whereas New York can be subjected to hurricanes. Still, there is much to be learned from the UK’s example. The TE 2100 project is a powerful lesson in climate change adaptation; or, as the IPCC defines it, “the adjustment in natural and human systems in response to actual or expected stimuli.”
The TE2100 does not stand alone, though. Mayor Bloomberg’s PlaNYC project likewise seeks to address long-term threats over the next 25 years by emphasizing sustainability, repairing city infrastructure, and conserving resources. The NYS Department of Environmental Conservation created an interagency task force in 2007 focused on adapting to sea level rise and plan to publish their final report of recommendations this December. Governor Schwarzenegger of California has issued executive orders commanding the California Resources Agency to conduct Sea Level Rise Assessments. The Netherlands has their Deltaworks system and Venice the Mose System. Adaptive measures have been cropping up in legislature around the international community. The message is out there and it is clear: act now or pay the price later.
Photo source: www.freefoto.org