Cities and Biodiversity Outlook
Biodiversity and ecosystem services are critical natural capital

Quantifying the value of ecosystems in both monetary and non-monetary terms and/or attaching qualitative values are important tools for mainstreaming ecological considerations into the management of a city

Natural capital, the stock of goods and services that are provided by ecosystems, are essential to humankind. The recognition, assessment and documentation of ecosystem services, and their valuation in economic terms, has been aptly described in the global study "The Economics of Ecosystems and Biodiversity" (TEEB).

Attaching monetary values to ecosystem services can be enormously useful to those concerned with biodiversity management. The City of Cape Town, South Africa, for example, recently calculated that for every unit of currency (one South African Rand, ZAR) the municipality spends on the environment, at least 8.30 ZAR of ecosystem goods and services is generated.

By illustrating that natural capital contributes to job creation, saves money, and complements services already provided by municipalities such as disaster-risk management and food security, municipal leaders can be encouraged to make decisions that favor the environment rather than harm it. At the same time, such efforts can garner broad public support for conservation, and even attract public and private investments.

Payment for ecosystem services (PES) schemes can be established, which offer incentives to landowners and farmers to manage their land sustainably. In Curitiba and Belo Horizonte, Brazil, private landowners are rewarded with tax breaks for managing their land sustainably. New York City has made substantial payments to upstream land managers in the Catskill/Delaware watershed to improve land-use practices and thereby ensure the provision of high-quality drinking water, as well as avert the need to build costly water-purification facilities. Citizens can thereby enjoy the direct benefits provided by nature and avoid paying to restore or replace degraded ecosystems.

Well-functioning ecosystems can also prove crucial to prevent financial losses and safe-guard human well-being. When Hurricane Katrina struck New Orleans in 2005, the severity of the effects was a direct result of human engineering projects that dried up the natural wetlands. The ecosystems' natural buffer capacity became severely compromised, and the city was devastated by the disastrous flooding. One of the few positive outcomes of the tragedy was a growing realization that restoration of green infrastructure is necessary to counter future storms, especially in the face of projected sea-level rise.

AICHI TARGET 2: By 2020, at the latest, biodiversity values have been integrated into national and local development and poverty reduction strategies and planning processes and are being incorporated into national accounting, as appropriate, and reporting systems. Mainstreaming of biodiversity needs to be done at national as well as sub-national and local levels to be effective. Biodiversity values are different for each level of "vertical" (i.e., national, provincial, and local) and "horizontal" (i.e., divisions such as environment, planning, transportation, education, finance, and nutrition) government.

The Economics of Ecosystems and Biodiversity
TEEB is a major international initiative to integrate the valuation of ecosystem services and biodiversity— appropriately referred to as "natural capital"—into governance and management, including at the city level. TEEB draws attention to the global economic benefits of biodiversity, highlights the growing costs of its loss and of ecosystem degradation, and draws together expertise from science, economics, and policy to enable practical actions. The impetus for TEEB came from the growing recognition that the benefits of nature mostly bypass markets, thus escaping pricing and defying valuation—and that this lack of valuation is an underlying cause for ecosystem degradation and loss of biodiversity. TEEB has made a compelling economic case for the conservation of natural capital. Its many reports evaluate the costs of the loss of biodiversity worldwide and compare them with the costs of effective conservation and sustainable use. TEEB's "Local and Regional Policy Makers Report" illustrates how dependent municipalities are on nature, and that nature has cost-effective solutions to local problems such as drinking-water supply and air-pollution control. "TEEB Manual for Cities" helps urban and regional policy-makers and planners assess the value of natural systems and consider opportunities and trade-offs of their policy and planning options. Other TEEB reports with a focus on the business sector, national government, and citizens are available for download at the TEEB website.

The Value of Restoring Biodiversity: Mayesbrook Park, London
A partnership of public and private organizations in a densely urban area of East London has transformed a formerly rundown 45-hectare park into a showcase of how public green space can help a community cope with the risks from climate change, such as increased flooding and higher summer temperatures, while also providing socioeconomic uplift. The project involved rehabilitating the Mayes Brook, creating a new floodplain that can naturally and safely store floodwater, planting new shrubs and trees to provide shade and enhanced habitats for wildlife, and adding new footpaths and signage so the public can better use the park. A 2011 assessment of the project's economic benefits demonstrated that an investment of £3.84 million in restoring degraded habitats and enhancing the green infrastructure will yield a lifetime benefit-to-cost ratio of approximately 7:1. The gross annual benefit delivered by the ecosystem services is estimated at approximately £880,000. The cultural services—including recreation, social relations, and education—return a gross annual value of approximately £820,000, demonstrating how the restoration of biodiversity can provide economically robust climate-change adaptation and also enhance the well-being of city-dwellers.

Water Purification through Wetlands: Nakivubo Swamps, Uganda
The Nakivubo Swamps are adjacent to Uganda's capital city, Kampala. The local government had proposed draining the swamps to make way for agriculture, but when a study revealed that this ecosystem was providing a valuable service by filtering organic waste and other effluent derived from Kampala, the proposal was promptly dropped. The study indicated that a water-purification facility capable of performing the same service would cost several million US dollars to construct and US$ 2 million a year to maintain. In this case, the value of converting land for agriculture would be offset by the cost of lost sewage-treatment capacity. Direct investment to maintain the wetland was a cost-effective measure to uphold the purification service. This example demonstrates how detailed information and cost estimates can better inform planning decisions.

Wetlands and Floodplains Protect Coastal Cities: New Orleans
Flooding has always been hazardous for the City of New Orleans in the southern USA. Extensive levees were built to mitigate flood risk, and surrounding wetlands were drained to combat disease such as mosquito-borne yellow fever and to open the way for further urbanization. In losing water, peaty soils compressed, subsided, and steadily sank below sea level. The levees prevented sediment-rich waters of the Mississippi River from adequately replenishing the floodplains and wetlands. Today more than 3,000 kilometers of levees line southern Louisiana's waterways, and intensive engineering has rerouted vast volumes of water. Numerous upstream dams trap sediment, further depriving the delta of silt. This rapid disappearance of coastal wetlands has undermined the region's capacity to absorb storm flow. In 2005, New Orleans paid dearly for this spectacular loss of green infrastructure when the city was devastated by the disastrous flooding of Hurricane Katrina. One of the few positive outcomes of that tragedy is a growing realization that restoration of green infrastructure is necessary to counter future storms, especially in the face of projected sea-level rise.

Ecosystem Valuation in Cape Town
The City of Cape Town, South Africa, recently undertook an intensive assessment of the value of ecosystem services generated by natural areas in the city. These areas include nature reserves, coastal areas, wetlands, and rivers. Using valuation methods such as "willingness to pay," the study estimated the net present value of the city's natural assets as US$ 5.13-9.78 billion. The study has helped leverage funding for the environment from across departments by revealing the considerable contribution of ecosystem services to human welfare and underscoring the need to account and pay for their maintenance.

Intact Forests and High-Biodiversity Wilderness Areas

Figure 1: Intact Forests and High-Biodiversity Wilderness Areas
An Intact Forest Landscape is an unbroken expanse of natural ecosystems within the zone of current forest extent, showing no signs of significant human activity, and large enough that all native biodiversity, including viable populations of wide-ranging species, could be maintained. (Data: HBWA) The IUCN Protected Areas Classification System defines wilderness as " large areas of unmodified or slightly modified land and/or sea, retaining their natural character and influence, which are protected and managed so as to preserve their natural condition ". The HBWA approach is an adopted priority setting template developed by Conservation International (CI) which refers to 5 of the 24 identified major tropical wilderness areas that hold globally significant levels of biodiversity. They are Amazonia, the Congo forests of Central Africa, New Guinea, the Miombo-Mopane woodlands of Southern Africa (including the Okavango Delta), and the North American desert complex of northern Mexico and the Southwestern part of United States of America. The intact portion of these areas covers 8,981,000 km2 (76% of their original extent), and 6.1% of the planet's land area.
Source: HBWA

Mangroves

Figure 2: Mangroves
Mangroves are various types of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics — mainly between latitudes 25° N and 25° S. The remaining mangrove forest areas of the world in 2000 was 53,190 square miles (137,760 km²) spanning 118 countries and territories.
Source: UNEP-WCMC

Tree Planting in Canberra

Figure 3: Tree Planting in Canberra
In Canberra, Australia, local authorities plant trees to generate a wealth of benefits. More than 400,000 trees can be found within the city limits. This urban forest helps mitigate the urban heat island effect, thereby reducing the need for energy-intensive air-conditioning and ventilation. The trees also improve air quality, intercept and absorb storm water, and sequester carbon. In terms of value generated or savings incurred, these services were valued at approximately US$ 20-67 million for the period 2008-2012. The valuation has helped inform planning and budget allocations.
Photo: Digital Globe / Google Earth

Ecosystem Services

Figure 4: Ecosystem Services
Humankind benefits from a multitude of resources and processes that are supplied by ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes such as the decomposition of wastes.
Source: TEEB

Nakivubo Swamps, Uganda

Figure 5: Nakivubo Swamps, Uganda
The Nakivubo Swamps are adjacent to Uganda's capital city, Kampala. The local government had proposed draining the swamps to make way for agriculture, but when a study revealed that this ecosystem was providing a valuable service by filtering organic waste and other effluent derived from Kampala, the proposal was promptly dropped. The study indicated that a water-purification facility capable of performing the same service would cost several million US dollars to construct and US$ 2 million a year to maintain.
Photo: Digital Globe / Google Earth

Intact forests, high-biodiversity wilderness areas and freshwater bodies

Figure 6: Intact forests, high-biodiversity wilderness areas and freshwater bodies
Intact Forests An Intact Forest Landscape is an unbroken expanse of natural ecosystems within the zone of current forest extent, showing no signs of significant human activity, and large enough that all native biodiversity, including viable populations of wide-ranging species, could be maintained.
HBWA The IUCN Protected Areas Classification System defines wilderness as "large areas of unmodified or slightly modified land and/or sea, retaining their natural character and influence, which are protected and managed so as to preserve their natural condition". The HBWA approach is an adopted priority setting template developed by Conservation International (CI) which refers to 5 of the 24 identified major tropical wilderness areas that hold globally significant levels of biodiversity. They are Amazonia, the Congo forests of Central Africa, New Guinea, the Miombo-Mopane woodlands of Southern Africa (including the Okavango Delta), and the North American desert complex of northern Mexico and the Southwestern part of United States of America. The intact portion of these areas covers 8,981,000 km2 (76% of their original extent), and 6.1% of the planet's land area.
Source: Conservation International, Intact Forest Landscapes & Global Lakes and Wetlands Database

Wheat, Rice and Maize

Figure 7: Wheat, Rice and Maize
This map shows the production areas of the three main edible grains consumed by humans: what, rice and maize. Human land use activities are a force of global significance. Humans have extensively modified the Earth's land surface, altering ecosystem structure and functioning, and diminishing the ability of ecosystems to continue providing valuable resources such as food, freshwater and forest resources, and services such as regulation of climate, air quality, water quality, soil resources. Agricultural activities have been responsible for a vast majority of these land use related ecosystem consequences. Nearly 40% of the planet's ice-free land surface is now being used for agriculture, and much of this land has replaced forests, savannas, and grasslands. Clearing of tropical forests for cultivation or grazing is responsible for 12-26% of the total emissions of carbon dioxide to the atmosphere, and land use changes can significantly modify regional and global climate. Furthermore, 20-30% of the total available surface water on the planet is withdrawn for irrigation, and nitrogen fixation through fertilizer production and crop cultivation currently equals or even exceeds natural biotic fixation.
Source: EarthStat