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Biodiversity and the City: A Case Study of the New York Metropolitan Region


William D. Solecki
Montclair State University
Cynthia Rosenzweig
NASA/Goddard Institute for Space Studies and
Columbia Earth Institute

May 21, 2001

Biodiversity and the City: A Case Study of the New York Metropolitan Region

This paper has two objectives. The first is to assess the dimensions of biodiversity-urban society interactions within the New York metropolitan region (a 31 county area with a population of 21.5 million). The second is to explore pathways to reconcile the current dysfunctional relationships. The principle mechanism proposed is the development implementation of the biosphere reserve strategy, and the creation of a NY harbor/estuary biosphere reserve.

This research incorporates three basic contextual elements. First, biodiversity and its maintenance are important in urban areas. Urban biodiversity will have impacts on local, regional, and global ecosystem and societal health. For example, coastal wetlands in urbanized areas can simultaneously provide sites for water runoff filtration, spawning ground for regional fisheries, and provide stopover points for migrating birds. A second element is that both the natural and built environments in cities are highly dynamic. We move away from the more traditional notions that the environments of cities are static and that once intensive development has taken place (e.g., urbanization) the ecological functions and properties disappear. Recent ecological research illustrates the dynamism and continual change of even the most urbanized sites. The third element is that urban ecologies will become even more dynamic in the future, particularly as a result of global climate change. Projected global climate change will cause enhanced changes to many of the biophysical baselines of ecosystems. For example, global climate-related increases in sea level rise could be up to 4 times greater than occurring naturally in the New York City region (Gornitz 2001).

Also underpinning the analysis is that the notion of regional identity and structure. The Hudson River harbor estuary area has long been the core of the New York metropolitan region. The latter part of the 19th and 20th centuries brought tremendous change and eventually degradation to this core. Throughout the paper, we present information on the changing resource demand of the region’s population, the associated change in regional identity and structure, and the decline of its traditional core, both literally and figuratively. Shifts in cultural values and economies have brought renewed interest in the harbor estuary region and calls for increased protection from groups and programs such as the NY/NJ Bay Keeper and the Harbor Estuary Program. As old port facilities and industries are replaced with residential and commercial developments, attention is again turning to this part of the region. We recommend that these efforts become formally designated for what is becoming - a laboratory for sustainability planning and a place where one can observe whether ecological restoration and economic development can occur side-by-side.

As global populations continue to increase more and more people will be living in urban environments. Today, more than 45% of the world’s population lives in developed urban areas. By the year 2025 it is projected that 5 out of 8 billion people will live in urban settlements (UN 1995). All these people will need resources like water, food, energy, sanitation facilities and places to live. This will present quite a logistical challenge for developed countries and even more of a challenge for third world nations with less developed infrastructure. The New York metropolitan region (NYMR) is a great example of a popular migration trend towards coastal cities.

According to the World Resource Institute, 40% of all cities with populations of 500,000 people or more are located on coasts or surrounded by wetlands (WRI 1996-7). This is intuitive in the sense that coastal areas represent some of the most productive arable lands and have historically been used for agricultural purposes. According to a recent IGPB report, coastal zone ecosystems occupy less than 8% of global surface area but are responsible for 26% of the world’s biologic production. It is becoming increasingly more important to identify and interpret the effects of urbanization on the environment.

The goals of this report are to ascertain the “ecological footprint” of the NYMR and to understand the roles and interactions of society within our complex ecosystem. The study will be geared to assess many different aspects of New York’s ecological footprint within the context of biodiversity and society. Further goals are to increase awareness and knowledge leading to better policies and resource management. The work done on the case study will expand on the climate change impact study already conducted by the Metropolitan East Coast Climate Assessment project. We will focus on issues pertaining to the estuary and wetlands, water supply, and energy supply. These issues encompass ever increasing geographical areas extending from this region throughout the entire world.

The People, Place, Pulse of the New York Metropolitan Region
The New York metropolitan region is one of the most important urban areas in the world (see Figure 1). As of the 2000 U.S. Census, the region has a total population of roughly 21.5 million, of which 8.0 million live in New York City. While the region is only an area of 13,000 square miles (33670 square kilometers), it maintains great physical and demographic diversity. The study area covers the 31 counties of the New York City metropolitan region. The jurisdictions include 1,600 cities, towns, and villages in the three states of New York, New Jersey, and Connecticut. The largest financial trading market of the world controls the economic heartbeat of the region. The NYMR general economy is mostly based on service industries, which depend on modern, sophisticated means of communication and transportation. Approximately, 10 trillion dollars of stock and bonds were exchanged in New York in 1999 (Warf 2000). The gross regional product (GRP) is estimated at ~$1 trillion.

Figure 1. The New York Metropolitan Region.

The Tri-State Region consists of nearly 20 million people living in approximately 1,500 cities,
towns and villages. It encompasses an area nearly 13,000 square miles across 31 counties at
the heart of the Boston-Washington “megalopolis.”

The New York Metropolitan Region

Map of 5 New York City Counties: Bronx, Kings, New York, Queens and Richmond.

The activities of this urban conglomeration place tremendous pressure on the regional land and water resources. Approximately 30% of the land area has been fully converted to urban uses. The regional water demand is 1500 million gallons per day (mgd), which presents decision-makers with increasing concerns about the quality and quantity of the regional water supply.

A complex web of formal and informal processes that involve the public, nonprofit, and private sectors governs the NYMR’s institutional framework for land use and development. The overarching considerations of environmental protection, health, and safety intertwine often. Institutional adaptation and flexibility must arise in order for links to form that will allow integrated decision-making regarding climate change.

With close to 1500 miles (2413.5 kilometers) of coastline, the region’s development has been intimately connected to the ocean. Infrastructure has emerged that fits this situation. For example, four of the five New York City boroughs are located on islands. More than 2200 bridges and a system of tunnels that carries rails and roads connect them with each other and the mainland. The NYMR maintains a versatile, high-volume transportation system by air, roads and rails (above and below ground), as well as on the water. These and other essential infrastructure elements are often used to capacity.

The region has a rich demographic history and is ever evolving. The region’s population grew dramatically throughout the latter part of the 19th, largely through massive immigration from Europe. While the region remained mostly rural through the mid-part of the 20th century, several large urban concentrations developed. Predominant among the urban centers on the eastern seaboard was New York City, which held by far the largest percentage of the region’s population. In 1950, the City made up 56.6% of the region’s 13.9 million people. Other significant urban concentrations included Newark, NJ, Jersey City, NJ, Yonkers, NY, and Bridgeport, CT, among other sites.

Since 1950, the population growth of the region has lagged behind that of other metropolitan areas in the United States. Even so, the population continued to increase and reached 19.7 million by 1990. By that time, New York City lost some of its dominance in the region. Population decentralization was an important demographic trend during this period. The City, by 1990, made up only 37.1% of the region’s population. Rapid suburbanization and associated white flight fostered a dramatically changed physical and social landscape. The rate of per capita land demand increased steadily during this period. Land conversion increasingly took Place on more vulnerable land including flood-prone areas and coastal locations. Coastal development was particularly intense along the Atlantic Ocean coasts of New Jersey and Long Island.

These shifts also have been associated with changes in regional employment patterns. Employment growth in the older urban counties has been very slow, and in many cases has shown absolute declines; while employment growth in the outer suburban counties has been very strong. For example, urban counties loss 307,000 jobs from 1970 to 1995; while the suburban counties gained 2,018,400 (U.S. Bureau of Economic Analysis, U.S. Census of Population).

Both of these shifts have meant a significant change in the overall level of wealth in the region. While some neighborhoods in New York City, particularly in Manhattan, remain extremely wealthy, the migration of the middle and upper middle class from older, urban areas along with a relocation of jobs has meant increasing spatial inequity within the region with respect to income levels. As of 1995 census estimates, almost 24% of the population lived below the poverty level in New York City; while the population living below poverty level in Connecticut was about 8%, in New Jersey it was nearly 9%. Nearly 16% of New York State’s total population (including the City) lived under the poverty level according to 1995 census data. For a large percentage of the region’s population, the high poverty levels correspond with lower access to adequate health care and other social services.

Another important component in the region is the increased racial and ethnic diversity of the population. While the New York metropolitan region has always been defined as a region of immigrants, the recent period of increased international migration has meant a further diversification of the population in the region. Many areas, both in urban and suburban, have significant ethnic, African-American, and Hispanic populations. In New York City, non-latino whites now make up less than 50% of population. Recent estimates note that 40% of the population in the City is foreign-born. The region also has large populations of elderly and immuno-compromised people, particularly people living with HIV/AIDS.

The New York metropolitan region has a very diverse landscape. It is a water-dominated region. Several large waterways and water bodies, such as the Newark Bay/Hackensack Meadowlands, the Hudson River, East River and Long Island Sound, Peconic Bay, Jamaica Bay, the Arthur Kill, and the Raritan River estuary, cut deeply into the land area. Three physiographic regions are present within the region including the coastal plain, the piedmont, and the Appalachian Highlands. Given the coastal location, much of the land area is a relatively low elevation. A limited amount of land (~1.0%) is below 3 meters in elevation. This land includes some of the most heavily developed land and regional important infrastructure such as lower Manhattan and portions of the three major regional airports.

The most prevalent natural hazards are flooding events either occurring from heavy precipitation or, in coastal areas, from storm surges. Tropical Storm Floyd in September 1999 was one of the largest storms on record with respect to damages. It cost an estimated $1 billion dollars worth on damage in the region. Other significant floods occurred in September 1882, October 1903, September 1966, and November 1977. The region also is subject to moderate droughts. The drought of record was in 1965 during which the region received 55 percent of the average rainfall (47.25 inches/per year). Other significant drought events occurred in 1910, 1935, and 1964. In typical years, rainfall is relatively evenly distributed throughout the year with a slightly higher level occurring in March and November.

The pre-historic ecology of the region has been tremendously modified. The region is now a heavily human-dominated landscape. Some exurban areas more distant from New York City, such as extreme eastern Long Island, northwestern New Jersey, and parts of Connecticut and upstate New York, still maintain extensive wildlife habitat and ecological function. The ecological function of the more settled part of the region is low; however, the few remaining larger-scale (i.e., greater than 500 hectares) habitat sites for example the Hackensack Meadowlands, the Great Swamp both in New Jersey and Jamaica Bay provide critical stopping points for the migratory bird species.

Critical and vulnerable habitats in the region have been heavily degraded. The vast majority of the region’s pre-historic wetlands have been lost. Buffer areas around wetlands or rivers typically are not present. In many areas, smaller rivers and streams have been filled, channelized or placed into culverts. Surface water and ground water supplies, particularly in the more heavily urbanized areas, have been compromised and typically exceed federal water pollution standards. In the region, there are more than 100,000 leaking underground fuel tanks, spill sites, or former industrial sites included on the federal government’s register of known or potential toxic sites (Yaro and Hiss 1996). Many are located in lowland locations where coastal wetlands were used as landfill sites. There are 131 active Superfund hazardous waste sites in the region.

The built environment comprises the most prominent feature of the region. The region maintained as of 1990, 7.7 million housing units, and current estimates include approximately 2000 miles (3218 kilometers) of major highway, and 1250 miles (2011.25 kilometers) of railway. Much of the built environment in New York City itself and adjacent older urban and suburban areas, pre-dates 1950. Maintenance of the infrastructure and buildings is a massive and continuing process. In the outlying counties, the vast majority of the construction is more recent. Currently, the greatest amount of new construction is taking place in these outlying areas. Revitalization and redevelopment is taking place in selected areas in the older urban core, such as the Hudson River waterfront area in New Jersey.

The region is highly dynamic. Highly complex socio-economic systems form the basis of the region’s pulse. The region is organized around massive inflows and outflows and intraregional flows. As a largely urban site almost all of the food supply has to be imported into the region, and increasingly much of the solid and hazardous waste is exported out. In the case of NYC water supply, fresh water also is brought into the region. Energy via the vast energy grid throughout the Northeast and Mid-Atlantic also is imported into the region.

Population migration also has been a significant component of the region’s pulse. In the past three decades more than 3 million people have migrated into the region. As a major port, the region is tied to the world through shipping. In 1999, over 40 million tons of bulk cargo passed through the ports of New York, Newark and Elizabeth (Port Authority of New York and New Jersey 2000). Another important component of the region’s pulse is the financial services industry. The NYMR is one of the most important financial and business centers in the world. Forty-three percent (861 billion) of all stock shares traded in the U.S. were traded on the New York Stock Exchange. New York also is the world’s largest advertising center with transactions of $37.7 billion in 1998 (Warf 2000). As such, local decisions and transactions that take place in the region everyday have important implications for locations throughout the world. Furthermore, any significant disruption to the communication and transportation systems can have dire economic consequences, not only locally, but also nationally and globally. An assessment of potential climate change impacts must take into account the possibility that future extreme weather events in the NYMR region could disrupt these activities.

Urbanization and the Environment
As global populations continue to grow, more and more people will be living in urban environments. Today, urban centers are home to about 45% of the world’s population (WRI, Urban Impacts on Natural Resources, 1996-7). By the year 2025, the global population is estimated to be 8 billion, and the majority of people, 5 billion, will be living in urban areas (UN, 1995). There are many differences in the patterns of resource use between rural and urban areas.

Urban areas tend to require more resources than their regions can provide and must import items like food, building materials and fuel from elsewhere. By contrast, in developing countries, local materials are used for building and people are still dependent on their own immediate resources for their livelihood (Douglas, 1994). For example, the consumption of biomass fuels from coal and forests provides between 25 to 90 percent of domestic energy supplies in rural and small urban centers (WRI).

One way of comparing resource use, land management and the carrying capacity of an ecosystem is by calculating an areas “ecological footprint.” The ecological footprint is defined as the amount of productive land needed to sustain a city’s population and its consumption levels (Rees, 1992). It is also a measure of how much land and resources are left over from urban enterprises to support and sustain a healthy biosystem (Folke et al, 1995). Because consumption levels increase linearly with increases in wealth, urban areas produce a disproportionate amount of waste and pollution. In the United States, for example, it takes at least 9.7 hectares per person (1 ha corresponds to about the size of a soccer field) to support our population (Wackernagel, 1996). This is about double the European average, ten times the footprint of India and compared to less than 2.2 ha per person in the rest of the world (Wackernagel and Rees, 1996). The U.S. ecological footprint is so large; we must import a tremendous amount of resources from other parts of the world to meet demands.

It is becoming increasingly important to understand environmental impacts associated with increased urbanization and how these impacts will affect regional and global sustainability. One can define three major routes in which urban areas will affect the environment. These are conversion of land to urban uses, the extraction and depletion of natural resources and the disposal of urban wastes. Today, 40% of all cities with populations of 500,000 people or more are located on tidal estuaries or open coastlines (WRI). Over fifty percent of the world’s coasts are threatened by development activities (Bryant et al, 1995). Although coastal zone ecosystems occupy 8% of the global surface, according to an IGPB report, it accounts for 26% of all biological production.

Farmers are responding to increased demand of luxury products like coffee, teas and tobacco (see Figure 2). As societies become more technologically advanced and increase in wealth, there is more demand for these luxury products. There has also been a worldwide trend toward using animals as food. In developing countries in Asia, the production of meat, eggs and milk products increased by 470%, 436%, and 172% respectively between 1961 to 1963 and 1989 to 1991 (Heilig, 1996). In the same area, population grew by over 80% (FAO, 1993A,B). Another example of a shift in diet that has lead to less effective resource use has been animal meat intake in China. In the 1960s, 80% of daily caloric intake came from a diet of rice and starchy roots. Meat and other animal products contributed to 3.5% of daily food calorie supply. Today, China has increased its meat production tenfold. 8.4% of the average per capita calorie consumption, 1996) in China comes from meat. Most of the meat comes from pigs (Heilig, 1996). In comparison, meat and animal products made up 30-40% of European and North American diet. Meat products are an inefficient source of calories. In order to raise one cow acres and acres of grazing land must be converted at the expense of crops that can provide comparative caloric and nutritional intake.

Figure 2. Amount of Arable Land Used for Luxury Crops

Amount of arable land used for luxury crops.
Chart Information.

According to some estimates, human settlements take up about 4% of arable land (Heilig, 1996). This is taking into account cropland, forestland and other productive areas. In order to sustain the demands of large population, prime agricultural land, forests and wetlands are being transformed to urban use. Urbanization of productive areas results in the filling in of marshes and wetlands, constructing houses or resorts on beachfront property, large-scale reclamation projects like extending coastlines and renourishing beaches. Shoreline development has caused the destruction of habitats, coastal erosion and alteration of local hydrology with regional effects.

Land conversion also refers to the amount of land needed for residential housing, industrial growth and the creation of roads, which allow transportation. Unchecked development and bad planning result in the creation of urban sprawl. Sprawl is characterized by low-density development and vacant or misused land. These conditions lead to higher infrastructure and energy costs. Because people must commute to work in cars, transportation costs are higher and there are greater emissions of green house gases. Sprawl has also been criticized for aesthetic reasons as well.

Overall from 1982 to 1992, urban conversions increased from 21 million hectares to 26 million hectares. Of this, over 2 million hectares of forest land, 1.5 million hectares of cultivated cropland, 940,000 hectares of pastureland and 774,000 hectares of rangeland were converted to urban uses (USDA Soil & Conservation Service, 1995). In developing countries, an estimated 476,000 hectares per year of arable land are transformed to urban uses (WRI, 1996).

Local resources are not enough to sustain the demands of urban populations and are quickly overtaxed. In order for supplies to meet demands, key products like water, food, oil, paper and building supplies must be imported from other regions in order to sustain growth. Although urban resource demands are very high and might be unsustainable over the long term, living in urban environments can be more efficient. Recycling and composting becomes a greater possibility, because there is a large surplus of used materials and sufficient industrial and residential need to make the process more cost effective. Per capita expenditures on environmental protection and awareness are also higher in urban areas. This is true both in absolute terms and as a percentage of the gross national product (Poracsky and Houck, 1994).

One of the most important resources necessary for human and other organisms survivability depends on the presence of potable water. Contamination of ground water through industrial activity continues to have a deleterious effect on our ecosystems. According to a 1982 EPA survey, close to 45% of large public water systems served by groundwater was found to be contaminated with synthetic organic chemicals, heavy metals and other pathogenic substances (Miller 1996). Groundwater contamination is caused by many factors. Leaching from unlined or improperly constructed landfills, buried hazardous wastes like gasoline and toxic solvents, surface runoff of pesticides and manure, and leaking sewage control systems are all common sources of contamination.

The extraction and depletion of natural resources leads to fragmentation and destruction of natural habitats. The disruption of important components of food webs leads to a decrease in biodiversity and an increase in the fragility of ecosystems. Urban wastes are usually localized in a very small area. In New York City, Fresh Kills landfill is the only open landfill and services between 75-80% of NYC’s trash or approximately 14,000 tons per day (Miller 1996, Goldstein and Izeman 1990). Between 1-2 million gallons of leachate per day make its way into the surrounding wetlands (Goldstein and Izeman 1990). According to the NYC Dept. Of Sanitation the leachate is composed of contaminated water (99%), salts, ammonia and some heavy metals. Although a leachate treatment plant was opened up recently it will only be able to process about 20% of the total oozing from the site (Miller 1996). Currently, it is the largest landfill in the world and by the time it is scheduled to close completely it will be the highest point on the east coast from Maine to Florida (Miller 1996). In developing countries, waste management has consistently lagged behind increases in population. In some developing cities waste management infrastructure is not capable of pick up and removal of solid wastes (see Figure 3).

Figure 3. (Source: WRI Report, 1997)

Comparison of solid waste generation and waste collection
Chart information

In Cairo, Egypt, for example, 10 million people (UN estimate) are served by a 50 year old system designed to accommodate only 2 million people. Of India’s urban residents, fewer than 16% are served by sewer systems or water treatment facilities (Miller, 1996, p259). The release of untreated sewage directly into rivers, lakes and other water supplies has compound effects. Bacteria that are ejected with effluent require a high biological oxygen demand (BOD) and cause hypoxic conditions (lack of oxygen in water for marine life). For riverine and estuaries that are mostly heterotrophic this leads to sublethal and lethal effects to benthic (bottom feeding) and pelagic organisms. Also, the introduction of excess nitrogen and phosphorus from untreated wastes, surface runoff from croplands and detergents into water can lead to eutrophication. The excess nitrogen and phosphorus stimulate algal blooms that block sunlight entering the water and choke indigenous species.

Another alarming statistic about water consumption is the amount of potable water unaccounted for because of leaking pipes due to aging or lack of infrastructure. Even in developed countries like the United Kingdom, close to 25% of water cannot be accounted (Douglas, 1995). In some developing country cities the amount of water lost is much higher. In Dhaka, for example, more than 60% of water is unaccounted for from the time it is pumped from aquifers to the time it makes it to residential settlements.

Consumption levels and wealth are greater in developed urban environments and this translates into greater waste production. Americans generate more than 160 million tons of trash per year (145 metric tons). This figure does not include sewage sludge and construction wastes (Hillel 1991, Suflita). In 1990, about 42.8% of municipal landfills were made up of paper products (Suflita). Wealthier cities contribute disproportionately to global environmental problems like emission of greenhouse gases, creation of ozone, acid rain production, release of carcinogens and toxic materials, surface runoff contamination, erosion and natural resource depletion. The United States produces about 25% of the world’s CO2 emissions, yet only contains about 6% of the population (US-EPA, 1998).

Motor vehicles — cars, trucks, buses, and scooters — account for nearly 80 percent of all transport-related energy (Energy Balances, 1985-95.) In 1950, there were only 70 million cars, trucks, and buses on the world’s roads. By 1994, there were about nine times that number, or 630 million. Since about 1970, the global fleet has been growing at the rate of about 16 million vehicles per year. This expansion has been accompanied by a similar linear growth in fuel consumption. If this kind of linear growth continues, by the year there will be well over 1 billion vehicles on the world’s roads (American Automobile Manufacturers Association, 1993).

In China, for example, there are only about 8 vehicles per 1,000 persons, and in India, only 7 per 1,000 persons; by contrast, there are about 750 motor vehicles per 1,000 persons in the United States (AAMA, Motor Vehicle Facts and Figures 1996). The number of vehicles in China has been growing at an annual rate of almost 13 percent for 30 years, nearly doubling every 5 years. India’s fleet has been expanding at more than 7 percent per year. Worldwide, motor vehicles currently emit well over 900 million metric tons of CO2 each year. These emissions account for more than 15 percent of global fossil fuel CO2 releases. The growing use of internal combustion vehicles, especially in urban areas, will increase congestion, raise the demand for oil, worsen air pollution, and increase emissions of a variety of greenhouse gases, including methane, ozone, carbon monoxide, nitrous oxide, and, most important, CO2.

In 1993, the countries of the Organization for Economic Co-Operation and Development (OECD) accounted for about two thirds of total world CO2 emissions from motor vehicles, although these countries represented only 16 percent of the world’s population. If the linear growth in emissions characterizing the past 20 years were to continue into the next century, OECD countries would still account for fully 60 percent of global motor vehicle emissions by the year 2050 (WRI Energy Statistics and Balances of OECD Countries).

Biodiversity and Urban Society
Biodiversity is a term used to describe the state of a biological system and the complex array of ecological interactions that take place. We can calculate the effects that organisms have on their surroundings by measuring total biomass (dry organic weight), production or respiration (BOD) patterns in a given system. There are many other direct and indirect ways to measure the biodiversity of an ecosystem. We will use three components to define biodiversity in New York City (see Figure 4).

  • Diversity: The species richness in a given area. This includes population makeup, genetic variation and habitat diversity within specific communities.
  • Complexity: The series of dynamic interactions that make up interspecific as well as intraspecific species competition for a finite amount of resources.
  • Stability: The result of attaining and understanding the balance between resource demand and allocation in order to bring viability and sustainability on a local, regional and global level.
  • Figure 4. Components of Biodiversity

    Components of biodiversity
    Chart information

    Diversity of species can be measured in a few different ways 1) The physical number of species or species richness 2) its corresponding biomass and 3) the genetic variation found in species populations. Usually, greater genetic variation can be correlated with a healthy, robust population. Lack of genetic variation/frequency corresponds to diminished, weaker populations. Smaller populations can hit a critical point known as a genetic bottleneck which results in inbreeding and passing on mutations that are deleterious to fitness levels (Krohne, 1998).

    All organisms must interact within bio-geochemical cycles. Among the more important are the carbon, nitrogen, sulfur and phosphorus cycles. Generally, carbon cycles are the most important to living organisms. All known life on earth is carbon based. Carbohydrates, DNA and proteins, the essential building blocks of life are all made up of carbon based molecules. Most carbon can be found locked away in rocks and minerals and are freed up by volcanism and weathering of crustal and biogenic rocks. Carbon exists in the atmosphere in the form of carbon dioxide, which is the principle green house gas. In the oceans and rivers carbon dioxide is converted to the shells formed by plankton and macroinvertabrates like oysters and clams. On land, trees, plants, animals and decomposers cycle carbon back and forth from the soil to regenerating biomass.

    The scope of our ecosystem can be defined as the complex interactions between microbes, plants, insects and animals (including people!) reacting to changes in abiotic conditions. In NYC it is the disproportionate effects of human development and our subsequent resource needs that have a direct impact on the myriad of different species surrounding us, which in turn, impact human societies in new and different ways.

    Biodiversity is affected by interspecific and intraspecific competition for a finite amount of resources. Anthropogenic impacts on other species have had a considerable effect on biodiversity. The effects of urbanization have lead to fragmentation and destruction of natural habitats, introduction of exotic species and an overall decrease in biodiversity. By some estimates, between 20% to 60% of animals and plants in the Hudson River System are exotics and have systematically replaced many native populations (Mills et al, 1996). These exotics continue to reproduce at unprecedented levels because they lack predators that would ordinarily work to keep their populations in check.

    Each case study will include an appraisal of the current situation and the processes that are being affected. We will then assess the impacts on the NYMR and discuss opportunities for improvement, particularly the application of the biosphere reserve concept to the NYMR. The report will be broken down into four major sections representing different levels of NYC’s environmental footprint and will incorporate selected case studies:

    I. Regional Issues: Land and Water Issues: Resource Management and Regional Planning. Biodiversity and the Anthropogenic Impacts on the Hudson-Raritan Estuary, NYC Harbors and Long Island Sound. The current state of pollution and the effects sewage abatement programs
    II. Ecological Footprint of NYC: Determining a per capita and total use of resources for: food, agriculture energy, raw materials, transportation, waste management and a measure of the amount of land needed to sustain our regional ecosystems.
    III. Urban/Suburban Differences: Using the developed items from sections I and II we will define differences in terms of per capita demands and the reasons for the differences in land, water supply, energy, food, other raw materials, and waste production.
    IV. Impacts of a Dynamic Environment: Climate change in the 21st Century. Urban impacts on a global scale. Including: temperature changes, rainfall, green house and other emissions, compound effects of sea level rise and immigration of people to progressively urban environments.

    Ecological Footprint of the New York Metropolitan Region:

    Within and Outside the Region
    The concept of the ecological footprint can be defined as the interactive relationship between and urban areas and its hinterland. This relationship is often defined as the measurement of resources extracted and waste emitted for a given city or urban region. Spatially, the ecological footprint can also be defined as the area from which a city draws its resources and to which it delivers its wastes. This concept is applied to assess the ecological footprint of the New York metropolitan region.

    Recent population figures show that 8.1 million people live in NYC and upwards of 12 million people live in the adjacent areas (U.S. Census 2000). High population densities in NYMR have had an adverse impact on the biodiversity of local flora and fauna. Our large, relatively wealthy population consumes more goods and resources than some developing countries. One of the byproducts of our consumer society has been the production of a tremendous amount of waste products. Approximately 14,000 tons of garbage is produced each day (Miller 1996), while some 2.5 billion gallons of treated effluent are flushed into the Hudson-Raritan Estuary (Hydroqual, Inc., 1991). Some locales in the region are perhaps some of the most contaminated in the country. There are unacceptable levels of organo-pollutants (PCBs, PAHs,) carcinogens and heavy metals (i.e. cadmium, lead, mercury) floating freely in the water, trapped in sediments and bioaccumulated in the tissues of marine organisms.

    Probably one of the most obvious elements of the local resource demand is water use, particularly the withdrawal and conveyance of drinking water to the region’s 21.5 million residents. The water systems of New York City, the Delaware Basin, and other adjacent systems to the west in New Jersey and to the east on Long Island are generally mature infrastructure systems with well-developed institutions that include city, state, and county agencies and the Delaware Basin River Commission, an intergovernmental agency chartered by the U.S. Congress, and an intergovernmental group formed as a result of the work of the New York City Mayor’s Intergovernmental Task Force on New York City Water Supply, the Southeastern New York Intergovernmental Water Supply Advisory Council (Major 2001).

    Changes in the system from 1950 to 2000 have involved: massive infrastructure expansion; a downward impact on estimates of system yield due to the drought of the 1960s; demand management; and more recently, active watershed management for water quality protection. After World War II the system was substantially expanded to include the Delaware reservoirs, which now supply 50% of the system’s water. These include the largest storage reservoir in the system, Pepacton (in service date 1954), as well as Cannonsville, Rondout, and Neversink. This expansion brought not only the reservoirs, but also the regulation of the Delaware according to Supreme Court decrees, and the formation of the Delaware River Basin Commission.

    Among the various regional water supply systems, the NYC water supply is by far the largest. The New York City Water Supply System stretches from upland reservoirs in the Catskills down through all parts of New York City (see Figure 5). Water is collected from upland watersheds, held in storage reservoirs, and sent via a system of tunnels and aqueducts through balancing and distribution reservoirs to distribution mains in the city and other user areas. Water is collected and stored in three upland reservoir systems: Croton, which began service in 1842 and was completed as a system prior to World War I; Catskill, completed in 1927; and Delaware, completed in 1967. The total area of the watersheds is nearly 2000 square miles (~5000 square kilometers). The three systems meet respectively about 10%, 40%, and 50% of the total daily system demand. The systems deliver water to the City via the New Croton Aqueduct, the Catskill Aqueduct, and the Delaware Aqueduct. The New Croton Aqueduct delivers water from the Croton System to the Jerome Park Reservoir in the Bronx. Catskill and Delaware water flows via Kensico Reservoir to Hillview Reservoir, just north of the City line.

    Figure 5. New York City Water Supply System

    New York City Water Supply System
    Chart information

    From Hillview Reservoir, City Tunnels #1 and #2 deliver system water to the City distribution system, which includes some 6,000 miles of mains varying in size from 6 to 96 inches in diameter. City Tunnel #3 is now under construction. Its first stage, which runs from Hillview Reservoir in Yonkers through the Bronx and Manhattan and under Roosevelt Island to Queens, was put into service in 1998. When the tunnel is completed through its second stage it will provide not only additional capacity but also the opportunity to shut down City Tunnels #1 and #2 for inspection and rehabilitation. The 18 impounding reservoirs, three controlled lakes, aqueducts, tunnels and water mains that make up the city water supply and distribution systems together constitute a monumental hydraulic and civil engineering achievement. Detailed descriptions of the system can be found in the documents issued in connection with proposed bond sales (New York State Environmental Facilities Corporation, 1998); see also Major (1992); New York City Mayor’s Intergovernmental Task Force on New York City Water Supply Needs (1992); U.S. Geological Survey (1997).

    The total storage capacity of the upland system is 547.5 billion gallons. The safe yield of the upstate elements of the system is currently estimated to be 1,290 million gallons per day (mgd), with 240, 470, 480 and 100 mgd available from the Croton, Catskill, Delaware and Rondout watersheds, respectively. The average daily system water supply provided to users in recent years has been on the order of 1400 mgd, reflecting a downward trend since 1989. In 1997, system supply was 1307 mgd, which is attributable in part to metering and conservation measures.

    The NYMR also faces huge demands on places very distant as well. For example, the population’s demand for energy and food extends throughout the globe. The region annual energy demand is equivalent to approximately 1 billion barrels of petroleum products (e.g., gasoline) that is equivalent to approximately 50% of the U.S. annual production of petroleum (2 billion barrels in 2000 - U.S. DOE 2001). Food demand also is massive. Almost all of the region’s food must be imported, especially as some of the remaining farmland is converted to suburban land uses. With respect to the ecological footprint of the region’s food demand, it is estimated that the population of NYMR annually consume approximately 800,000 hectares of wheat that is equivalent to the total acreage of wheat grown in the state of Nebraska.

    Waste disposal is another aspect of the ecological footprint. Historically much of the waste disposal has taken place locally either via land filling or ocean dumping. Volumes and types of materials disposed of have changed over times as well (see Figure 6a & 6b). Increasingly, more wastes are being exported out of the region as dumping restrictions are put into place, and waste facilities become more difficult to site. In recent decades, dozens of landfills in the region have closed. The famous Arthur Kill landfill on Staten Island, the last operating facility in New York City closed during the early in 2001. Today, train loads of residential and commercial waste is shipped hundreds of miles out of the region to states throughout the Middle Atlantic and Midwest, particularly Pennsylvania, Ohio, and Virginia.

    Figure 6a.

    Urban organic nitrogen: human v. horse

    Figure 6b.

    Arsenic and lead emissions
    Chart information

    Urban, Suburban, and Hinterland Resource Differences
    While the region as whole can be defined as a having an ecological footprint, it is recognized that there is significant demographic and spatial variation in the level of demand. The decentralization of the region and the rapid growth of far-flung suburban and exurban communities has been associated with increased resource demands. This pattern of suburban development means increased land, water, and energy per capita demands.

    As the region grew more land was converted to urban uses. This includes conversion to industrial, commercial and residential areas. Over 30% of the total land area of the New York Metropolitan Area has been converted to urban uses. In recent decades, the amount of land conversion per capita has rapidly increased as extensive amounts of suburban sprawl are created. There is currently a more than 30-fold difference in density measures between the five boroughs of New York City and the rest of the 26 counties in the region (see Table 1). The result has been a significant decrease in vegetative cover as well as fragmentation and destruction of habitats. The Regional Plan Association, the premier metropolitan regional planning organization, has labeled NYMR as a “region at risk” (Yaro and Hiss 1996).

    Table 1.

    Geographic Area


    (2000 Census)

    Area (square
    miles) (2000)

    Density (2000)









     New Haven





    New Jersey

























































    New York
    (without NYC)








































    (average) 1094.01


    New York City




     Kings (Brooklyn)




     New York (Manhattan)








     Richmond (Staten Island)








    (average) 32278.16

    Suburbanization also brought greater demand for water resources, particularly for watering lawns and gardens and filling swimming pools. While only a relative small percentage of the region’s have swimming pools, most suburbanites by definition have lawns and gardens onto which they use high quality drinking water to ensure vigorous growth. Overall water demand among urban residents is much lower.

    A similar scenario is played out with respect to energy use. Urban areas, because of economies of scale, promote public transportation and walking while newly suburban areas are built around the automobile.

    Impacts of a Dynamic Environment: Global Climate Change
    The recent Metropolitan East Coast Regional Assessment’, carried on from 1998 to 2000, provides the case study for this investigation (Rosenzweig and Solecki, 2001). Global climate models predict that New York in the 21st century will experience higher temperatures throughout the year and more heatwaves in summer, rising seas, shorter recurrence periods for severe storms, and increased frequencies of drought and flooding. These climate shifts, in turn, are likely to inundate coastal wetlands, threaten vital infrastructure and water supplies, augment summertime energy demand, and directly and indirectly affect public health, all at the same time. Climate change may be viewed as the ultimate stress on a city where the dense population already puts tremendous demand on land and water resources (Aspen Global Change Institute, 2000).

    In the MEC Regional Assessment, researchers and stakeholders utilized historical climate trends, current climate extremes, and future climate change scenarios to study climate-society interactions. Future climate change scenarios are “practice climates,” based on current climate trends and projections of global climate models, defined as plausible combinations of climatic conditions that may be used to project possible impacts created by climate change and to evaluate responses to them.

    Climate change is already occurring in New York. Over the past century, average regional temperature has increased about 2°F, after the effects of the urban heat island have been removed (Fig. 7). (Buildings and concrete absorb heat during the day and release it at night, making cities warmer than surrounding areas) Warming since 1950 may be at least partially attributed to anthropogenic increases in greenhouse gases (Karl et al., 1995; IPCC, 1996). Precipitation levels in the region have increased slightly by an average of about 0.1 inch per decade over the past century.

    Figure 7.
    A Dynamic Environment
    Historical Climate Trends

    Historic Climate Trends
    Chart information

    Climate change projections for New York City have been derived from global climate models (GCMs). Projected changes in New York City’s annual temperature and precipitation for the four GCM scenarios and for continued current trends are shown in Figure 8. The GCM-projected temperature changes are higher (from 4-10°F by the 2080s) than those projected by current trends (over 2°F in the 2080s) because the GCM scenarios account for increasing feedback from greenhouse gases that act as forcing mechanisms to warm the Earth’s atmosphere. Precipitation projections for the region do not agree in magnitude or direction (-20% - +30% by the 2080s), indicating hydrological uncertainty in the future.

    Figure 8.

    Climatr Change Senarios
    Chart information

    Sea level rise associated with global warming will result in widespread impacts on a region as closely linked to the ocean-land interface as New York. The current rate of sea level rise is approximately 0.1 in/yr, with some regional variation (Gornitz, 1995). About half of this rate is associated with regional land subsidence linked to isostatic rebound of formerly glaciated land to the north; the other half is associated with the observed rise in global mean temperature rise (~1.2°F) over the period from 1900 to 2000. Climate change will foster further sea level rise because of increased melting of glacial ice (e.g., the Greenland icesheet) and thermal expansion of the upper layers of the ocean.

    The key threat of sea level rise is its effect on storm surges. Heightened storm surges associated with future hurricanes and nor-easters (strong winter extra-tropical cyclonic storms) will cause the most significant damage. Given the projected rates of sea level rise, Gornitz (2001) and Gornitz et al. (2001) have estimated that under a worst-case scenario by 2090, a coastal storm event comparable a 100-year flooding could occur every 3-4 years (see Figure 9, and in more extreme and uncertain estimates a 500-year flooding event could occur every 50 years (Jacob 2001). Even a more moderate compression of the extreme flooding interval can have large impacts.

    Figure 9.

    Reduction in 100-year flood return period
    Chart information

    Many of the region’s most significant infrastructure features will be at increased risk to damage resulting from the augmented storm surges (Jacob 2001). The default public policy of placing necessary yet locally unwanted land uses (LULU) on marginal lands, such as transportation infrastructure across and along the edges of wetlands, bays, and estuaries, may engender some unintended consequences. The Hackensack Meadowlands in northern New Jersey serve as good example. The low-elevation, degraded wetland has dozens of vulnerable air, train, ship, road, and pipeline infrastructure features.

    A different vulnerability is exhibited by the region’s salt marsh wetlands. Under natural conditions, wetlands respond to sea level rise through accretion and in-migration; however, many of the wetlands in the New York metropolitan area can no longer respond this way because of the reduction of sediment input and upland migration sites resulting from extensive land development in the coastal zone. The few remaining coastal wetlands provide critical habitat to local and migratory animals, particularly for waterfowl species. The wetlands also protect inland development from storm surges and can act as water purifiers by natural filtration.

    Severe wetland loss in the region’s remnant coastal marshlands has already been recorded. Recent research indicates that salt marsh islands in the Jamaica Bay Wildlife Refuge, part of the Gateway National Recreation Area, have decreased approximately 10% in size from 1959 to 1998 (Hartig et al., 2001). Given that much of the decline in sediment input took place in the early decades of the 20th century, a significant amount of this loss is likely to have resulted from the already occurring sea level rise. Future scenarios illustrate that rate of sea level rise is likely to continue to exceed the accretion rate of the wetlands by the mid-part of this century causing even more rapid disappearance of the wetlands.

    The Biosphere Reserve Concept and the New York Metropolitan Region
    The biosphere reserve concept has emerged and been put into Practice at hundreds of sites throughout the world over the past 30 plus years (UNESCO 1996). To date, it has almost exclusively been applied to wilderness sites or rural sites away from major settlements. The application of the concept to urban areas has been formally under review by UN Man and the Biosphere committees during the past two years (UNESCO 2000). While this discussion is still underway, the application of the biosphere reserve concept to the NYMR is presented here as a way reconciling the dysfunctional relationships between biodiversity and urban society in the region. In this case, the New York Upper and Lower Bay and adjacent coastal areas are presented as the biosphere reserve core, and the outlying areas are defined as the buffer and transition Areas with its natural and built elements which will be structured to manage and protect the core (Fig. 10).

    Figure 10. The New York Metropolitan Region Proposed Biosphere Reserve

    Proposed metropolitan area biosphere reserve
    Chart information

    At the conceptual level, application of the biosphere reserve strategy will enable resource decision-makers to better understand the connections between biodiversity and urban societal demands, more responsive to potential environmental changes on longer time horizons, and flexible in the face of increased uncertainty. At the operational level, a NYMR biosphere reserve will provide an excellent pathway for integration of new environmental management proposals, such as climate change adaptation strategies into stakeholders’ decision-making practices. Several initiatives will help to build the necessary foundation for these pathways to be followed. These include: (1) education and outreach programs; (2) enhanced methods for defining and entraining potential biodiversity impacts into planning decisions, and (3) increased inter-agency communication and cooperation.

    It should be recognized that regional planning efforts of this type have been inherently difficult to achieve in urban areas such as the NYMR, although several organizations and programs are currently work and achieve some success (such as the Regional Plan Association, Port Authority of NY/NJ, Metropolitan Transportation Authority Federal Agencies - EPA Region II, C.O.A.S.T, and the Harbor Estuary Program). Gunderson et al. (1995) discuss some of the potential barriers. In a region of more than a thousand jurisdictions, home rule and a splintered political landscape characterize the New York metropolitan region. Besides the federal government and several regional organizations, the region is divided jurisdictionally into 3 states, 31 counties, and hundreds of municipalities (Zimmerman and Cusker, 2001). In this setting, short-term political concerns tend to dominate, long-term biodiversity and ecological issues are often presented as having wide-reaching societal impacts. Policy responses to biodiversity protection are also hampered by the generally reactive nature of management organizations. Institutional action is often directed at immediate and obvious problems; issues that might emerge fully only after several decades are perceived as less pressing.

    Biosphere reserve planning efforts also have been difficult to implement also because of a set of other more specific issues. In the U.S., regional planning has often been presented as a fourth tier of governance which is not political favored. Another factor is that there is often a lack of knowledge of biodiversity and ecosystem function and therefore planning is difficult. Third, many biosphere reserves have to retrofitting onto existing core protection areas, e.g., Great Smokies National Park in the U.S. southeast, which is extremely difficult politically and logistically. Local residents and communities often fear a negative socio-economic impact and the forced decline of primary industries such as logging, mining, and ranching.

    The New York Metropolitan Biosphere Reserve would function similarly to other reserves in that the long-term objective will be to protect the regional biodiversity, become an observatory for long-term data collection and definition of ecological trends, and become a laboratory for sustainability planning efforts. This third function will be key for the New York urban reserve. Lessons learned at the site could be translated to other megacities throughout the world.


    We would like to thank Ben Lane, Christine Norodam-Alfsen, and Roberta Balstad Miller for constructive suggestions for the case study; Noah Edelblum for extensive work on an earlier version of this paper; and Mary Wiencke and Carolin Stroehle for gathering data and references and helping to organize our case study workshop.


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