03/21/2013 09:21 am ET Updated May 21, 2013

Why We Must Put Nature Back to Work, Part 2

In its new assessment of America's infrastructure, the American Society of Civil Engineers (ASCE) found that much of it is aging and substandard. Among the systems needing repairs are dams, levees and storm water controls that are important to protecting the American people from the growing impacts of climate change.

At a time when government funding is strained, can nature offer some of the protection that engineered structures were built to provide? And can nature do it at lower cost? I asked three of the United States' premier experts on ecosystem services: Keith Bowers, president of Biohabitats Inc. in Baltimore; Dr. Bob Costanza, the ecological economist who coauthored one of the world's first assessments of the economic value of ecosystem service; and Professor Ed Barbier, a prolific author on the topic and a professor of economics at the University of Wyoming.

In Part 1 of the interview, we discussed how ecosystem services should be defined and how we can better quantify their value.

Q: Are there examples where ecosystems actually reduce pressure on local government budgets -- in other words, on taxpayers?

Bowers: Yes. The classic example is the water supply system for New York City. Instead of upgrading and building new water treatment facilities, the City decided to invest in protecting the source of the water in the Catskills. As a result they have saved billions of dollars while indirectly protecting a whole host of ecosystem functions and services that are enjoyed by the region at large.

There are other examples around the world including the protection and restoration of mangrove wetlands that protect against storm surges along coastal areas while also providing the nursery grounds for the shrimping and seafood industry. We are also recognizing that tree canopy in urban environments modifies the microclimate and absorbs storm water, greatly reducing energy demands and the need for extensive storm water collection and treatment systems.

Q: What cities are making the most effort these days to utilize ecosystems and their services? Who are the leaders?

Bowers: Federal clean water regulations are driving many cities to begin utilizing ecosystem services to assist them with meeting performance criteria. It's great to see that many cities are beginning to embrace what we call green infrastructure -- that is, using natural systems and their processes to replace gray infrastructure -- the pipes, roads, walls, and concrete that we have been using for the past 100 years. Cities with aging infrastructure are beginning to turn to green infrastructure as a viable, and in most cases, a cost-competitive and more effective alternative to conventional gray infrastructure. This is especially true when you begin to calculate the natural capital, or the ecosystem services that green infrastructure provides on top of its primary use.

Q: With all their benefits, ecosystems need to be understood as assets in our states and communities. Has anyone done an inventory of ecosystem services?

Costanza: The U.S. Environmental Protection Agency, the United States Geological Service, the Department of Agriculture and the U.S. Forest Service all have programs on ecosystem services. The EPA is creating a national atlas of ecosystem services that will be useful at multiple scales. In addition, some cities are taking stock. For example, Seattle has completed a three-year study of the benefits provided by its urban forest.

Q: As you all know, rural areas also are important to protecting ecosystems. For example, forest lands need to be preserved for carbon sequestration. Poor farming practices deplete the fertility of our soils. Logging and tilling can cause runoff that increases flooding and water pollution. The national agriculture program is coming up for re-authorization again this fall. What changes do we need in national policy to make sure we're not subsidizing the loss of rural ecosystem services?

Bowers: As Wes Jackson, the founder of the Land Institute, says, it's all about soils. We need an agriculture program that fist and foremost protects the structure, fertility and regenerative capacity of soils to provide us with the food and fiber we need. We also need to consider the ecosystem services that rural lands, including farmland, have the capacity to provide.

We need to be taking a whole-systems approach, looking at not only what the landscape can provide with regard to food and fiber, but how it can do so in a way that supports a full array of wildlife species; protects wetlands, aquifers and rivers; restores wildlife corridors and regenerates ecological processes that contribute to soil health.

Q: Are we seeing any progress in protecting ecosystem services worldwide?

Barbier: Global ecosystems and freshwater sources are clearly endangered by current patterns of economic development. Over the past 50 years, ecosystems have been modified more rapidly and extensively than in any comparable period in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber and fuel.

The result has been a considerable decline in the economic benefits provided by ecosystems. According to the Millennium Ecosystem Assessment, approximately 60 percent of the major global ecosystem services have been degraded or used unsustainably, including freshwater capture, fisheries, air and water purification, and the regulation of regional and local climate, natural hazards, and pests.

However, we may be slowly waking up to the current global ecological crisis, given the recent, large-scale coastal disasters that have occurred worldwide: the December 2004 Indian Ocean Tsunami; the 2005 Hurricanes Katrina and Rita in the U.S. Gulf Coast; the 2011 earthquake, tsunami and Fukushima nuclear disaster in Japan; and finally, last year's Hurricane Sandy in the Northeastern United States. Collectively, these disasters are a powerful reminder of the vulnerability of growing human coastal populations to natural disasters, and the important role of coastal ecosystems in this relationship.

I'm singling out coasts because more than 123 million Americans live in coastal counties and the number is growing. That's nearly 40 percent of our population that is vulnerable to climate impacts such as rising ocean levels and more severe coastal storms. We see the same vulnerability at the global level. There are a few points to keep in mind.

First, coastal human population densities across the globe are nearly three times that of inland areas, and they are increasingly exponentially. Thus as the human population grows, we are packing more people into our coastlines than ever before.

Second, many estuarine, coastal and marine ecosystems naturally protect coastlines from storm surges, wind, flooding, erosion and other impacts of storms, but as coastal development and populations expand, these systems are disappearing rapidly. Their resulting loss and degradation due to human activities is intense and increasing, such that 50 percent of salt marshes, 35 percent of mangroves, 30 percent of coral reefs, and 29 percent of sea grasses are either lost or degraded worldwide. Such rapid decline and deterioration of these systems are making coastlines more vulnerable.

Third, across all the cities worldwide, about 40 million people are exposed to a one-in-100-year extreme coastal flooding event, and by 2070, it will be 150 million people. Consequently, because of the growth of urban populations generally, and cities in coastal areas specifically, more and more cities are facing the growing risks of major storm events such as Hurricanes Sandy or Katrina.

Finally, the most vulnerable populations are likely to be in the poorest countries, and thus the least able to afford the risks and damages posed by coastal storms and floods. Around 14 percent of the population, and 21 percent of the urban dwellers in developing countries, live in low-elevation coastal zones that are exposed to these risks and damages.

Given these trends, there is an urgent need to develop a long-term strategy for investing in reducing the vulnerability of coastal populations to storm events. Such a strategy should have two primary features: protecting coastlines and populations to the risks posed by damaging storms, and restoring valuable coastal systems such as salt marshes, coral reefs, mangroves, sea grasses and sand dunes.

Once again, however, we are back to the crisis in ecological capital -- without our understanding what we are losing as ecosystems are irreversibly converted, and the consequences for human welfare -- then an import source of economic wealth is irretrievably lost, and as a consequence, the most vulnerable will suffer.

Q: The vulnerability of populations that are least able to cope is an issue that seems to cut across climate disruption. Is there also a relationship between poverty and the loss of ecosystem services?

Barbier: When any form of wealth of an economy declines, it is the poor that suffer disproportionately more. The same is true for the continuing decline in ecological capital worldwide. Poor people in developing countries will be most affected by the continuing loss of these critical ecological services.

In my book, Scarcity and Frontiers: How Economies Have Developed Through Natural Resource Scarcity, I argue that the world is entering a new era, the "Age of Ecological Scarcity." The main development challenge of this era is the implications for global poverty. Exacerbating the problem is that, compared to past eras in human history, economic growth through exploiting abundant "frontiers" of land and natural resources will no longer be the means to improve the livelihoods of the poorest human populations.

The rural poor in developing regions tend to be clustered in areas of ecologically fragile land, which are already prone to degradation, water stress and poor soils. In addition, by 2019, half of the developing world will be in cities and by 2050, 5.33 billion people, or 67 percent of the population in developed countries, will inhabit urban areas. This brisk pace of urbanization means that the growing populations in the cities will be confronted with increased congestion and pollution and rising energy, water and raw material demands.

Although such environmental problems are similar to those faced by industrialized countries, the pace and scale of urban population growth in developing countries are likely to lead to more severe and acute health and welfare impacts.

Bill Becker is executive director of the Presidential Climate Action Project and co-director of The Future We Want. Parts of this interview were extracted from a recent blog post by Prof. Barbier and an upcoming article by Bob Costanza.