Abstract
While there is little dissent in the scientific community that climate change directly correlates to human-caused greenhouse-gas emissions, action to reduce those emissions has not followed from the United States and many other governments around the world. Meanwhile, climate changes are already underway, and will continue to some degree even if emissions are drastically curtailed, thanks to emissions already in the atmosphere. Some countries and states are making their own plans to adapt to expected impacts including higher sea levels, more intense rainfall, droughts, heat waves, and loss of water supplies—and to reduce their local emissions. In this Global Forum, three experts highlight efforts by national and local governments in planning for 2100 and beyond. From the Netherlands, Arthur Mynett; from Bangladesh, Saleemul Huq (2011); and from California, Martha Krebs (2011). Over the months of January and February, this forum will continue at www.thebulletin.org.
The Netherlands is located in the delta of the Rhine-Meuse-Scheldt estuary, which collects water that drains from Germany, Northern France, Belgium, and Luxembourg. More than one-third of the country lies below sea level, partly protected by natural dunes, and partly by man-made dikes and storm surge barriers. Over the past centuries, the Dutch delta has been exposed to a number of severe floods, most recently in 1953, when a major storm ripped through the country, demolishing protective dikes in numerous places, causing severe flooding of hundreds of square miles of fertile land, and killing nearly 2,000 people and countless animals. Shortly thereafter, the Netherlands created the First Delta Committee to construct major protection works to safeguard the entire Dutch coast against future flood events. Known as “Delta Works”, the major projects were completed in the early 1990s.
With increasing understanding of changing climate conditions, it became clear that without a serious government effort, no safe living conditions could be secured and no economic activities could be sustained during the centuries to come. In order to deal with the threat of sea level rise, increased river floods, and prolonged periods of drought, the Netherlands considered the effects of climate change—notably those related to sea level rise and the increased variability in river discharge—by developing adaptive management strategies and exploring innovative technical solutions.
The Netherlands may be a small country, but it has set a large example in preparing for its future, despite the potential threats due to climate change.
A government approach: Taking action
The Dutch government’s attitude to climate change is that it wants to be prepared before disasters occur. The threat may not be immediate, but there is definitely a sense of urgency and a need to act now. Consequently, the government set up the Second Delta Committee—consisting of scientists, engineers, lawmakers, and politicians—and gave them the task to explore measures needed to safeguard the country until the year 2100 and beyond.
The challenge for the country is how to grapple with issues of sea level rise, increased river discharge, and extended drought periods, while maintaining pleasant living conditions and a vibrant economy in the Dutch delta for generations to come. Cost estimates of investments needed until 2050 range between 1.2 and 1.6 billion euros per year, and 900 million to 1.5 billion euros per year from 2050 to 2100.
The Delta Committee looks at more than water safety issues—it takes a holistic approach, by considering the relationships between the environment and working conditions, nature preservation and infrastructure development, and food production and energy supply. In addition to technical measures, socio-political, financial, and legal implications are taken into account as well: Socio-political considerations are important, and national and regional government agencies are working together through (i) a high-level ministerial steering committee and (ii) a permanent monitoring committee of the parliament. Financial reservations for all measures to be taken are secured by setting up a special fund within the Finance Ministry. Socio-political and financial issues are addressed in a legal framework. Topics such as the nomination of a program director, the maintenance of the financial fund, and amendments to the delta program are all to be part of this framework.
Though the government cannot accurately predict what the country will need in 2100, it does have the foresight to know that whatever it is, it must be safe and sustainable—the two pillars of the committee’s strategy.
Safety
Safety issues include protection against flooding as well as safeguarding an adequate freshwater supply. Ensuring this protection against flooding is considered of national interest—and one of the primary responsibilities of the Dutch government. Any major failure in one of the safety measures against flooding could have severe consequences for the entire national economy for a considerable period of time. Hence, measures to secure adequate protection levels are of vital importance.
Currently, the best estimates for sea level rise range from 0.65 m to 1.30 m in 2100 and from 2 m to 4 m in 2200, including effects of land subsidence. Although these numbers correspond to the most likely upper bounds of a wide range of ensemble predictions, the Delta Committee recommends that they be considered seriously when making decisions on developing long-term solutions. Safety levels are to be increased by a factor of 10 relative to present conditions, which already are considered among the most secure in the world. Present design levels for sea defenses correspond to a return period of 1 every 10,000 years; for river dikes, the return period is 1 every 1,250 years. Delta dikes are to be constructed to respond to the possibility of increased safety levels; such dikes (also known as “super levees”) should be either very high, very wide, or very strong in order to minimize the probability of uncontrolled failure and flooding. Completion of measures is to be achieved by the year 2050 and design conditions to be closely monitored after 2050 and updated if necessary.
Global warming and change in meteorological weather patterns could well lead to a reduction in river discharge in the summer months and an increase during the winter months. The maximum discharge for the Rhine River is likely to increase from 16,000 to 18,000 m3/s in the year 2100, and from 3,800 to 4,600 m3/s for the Meuse River. The combined effect of increasing sea level with decreasing river discharge and prolonged periods of drought can cause considerable salinity intrusion into the groundwater. This will directly affect the freshwater availability for drinking water supply and agricultural use. Moreover, low water levels in rivers and canals directly affect economic activities like shipping of goods from the Rotterdam harbor to the German Ruhr region. Also, power plants would fall short of adequate cooling water supply and may have to shut down, thus seriously affecting industrial and living conditions. In order to avoid potential problems related to high water levels or low river discharges, there are two approaches: Carefully plan infrastructure in and near flood-prone areas; this is to take into account urban growth, as well to consider roads, railways, and other means of communication. Develop innovative techniques for new ways of living inside floodplains, e.g. by developing floating houses that can sustain incidental extreme events.
Sustainability
As an important driver for developing adaptive management strategies that secure cost effectiveness and provide added value to society, sustainability is vital both economically and in terms of the environment. Measures will be developed that allow flexibility for future adjustments—like allowing an increase in the crest level of the dike in case the sea level increases—but that are already effective in the short run—like enhancing storm surge barrier heights. By following a “real options approach”—that is, simultaneously planning for both today and the future—it is envisaged that the Netherlands will be quite capable of dealing with effects of climate change as they occur, while concurrently creating new opportunities for future innovative approaches.
Building with nature
An important recent and innovative development in the Netherlands is the “building with nature” approach, which uses natural processes rather than opposing them, when developing structural measures. For example, the properties of natural river systems can be used, rather than using concrete to align riverbanks; natural forces of wind- and tide-driven currents in coastal seas can be used to transport sediment from nearshore dumpsites toward the beach, rather than supplying sediments directly on the beach; and water can be used to generate energy, making use of tidal variations, or density gradients between salt and freshwater systems to generate electricity.
Part of the natural defense line along the coast of Holland, Zeeland, and the Wadden Islands consists of sand dunes that are vulnerable to erosion by waves and currents, particularly in the case of extreme storms. In order to strengthen its natural coastline, the Dutch government set up a beach nourishment scheme to enhance sedimentation and create new land that can increase safety levels of densely populated coastal areas, or create new opportunities for recreational or industrial development. Appealing living conditions can be created in or near river floodplains, for example, by developing the concept of “floating houses”, which are moored to the shore, but built to easily float up and down, allowing considerable rise in water level.
Occasionally it may not be possible to use nature to build if space simply is not available for natural processes to develop, or the economic value of investments to be protected is simply too large to run any risk of dike failure. In such conditions, super strong dikes (also known as “super levees” or “delta dikes”) will be constructed, which make sudden incontrollable failure virtually impossible. Such super dikes can also contain roads and railroads that can serve as transportation devices, especially in case of emergency.
From threats to opportunities
Clearly a fundamental issue for the Netherlands is how to preserve the high standard of living for many generations to come, how to remain an appealing country for people to live in, and how to sustain a successful environment for industry investments. Such a challenge is not easily met, but conditions are favorable due in part to the nation’s foresight. New opportunities are likely to arise for developing an integrated approach to climate change adaptation. Such approach may become in great demand worldwide, in particular in low-lying delta areas.
This is where the Netherlands has developed strengths in the past, and this is where it wants to remain: at the forefront of building a sustainable future.
Footnotes
Author biography