Cities and Biodiversity Outlook
Urbanization is both a challenge and an opportunity to manage ecosystem services globally

Urban regions must take increased responsibility for motivating and implementing solutions that take into account their profound connections with and impacts on the rest of the planet

Urban areas are expanding faster than urban populations. The total urban area is expected to triple between 2000 and 2030, while urban populations are expected to nearly double, increasing from 2.84 to 4.9 billion.

This urban expansion will heavily draw on natural resources on a global scale, and will often consume prime agricultural land, with knock-on effects on biodiversity and ecosystem services elsewhere. Materials and energy are, and will be, drawn in great quantities from all over the world — often from large distances — to the primarily urban locus of consumption and waste generation.

Roughly 70% of the world's population is expected to be urban by 2050. Recent studies suggest that the global food supply will need to roughly double to meet the dietary needs of the growing population, global energy demand may increase up to 80%, and global water demand is expected to increase by 55% between 2000 and 2050.

Despite these challenges, there are untapped opportunities for cities to manage ecosystem services globally. For example, a combination of measures can be used to decrease waste and reduce meat consumption, while at the same time invest in protecting biodiversity, water quality, local food production and key carbon-sequestering ecosystems.

A global system of cities must operate within a framework of other actors such as national, regional, and local governments, multinational corporations, and civil society. Each of these actors has important roles to play in managing planetary resources.

Individual cities have begun to take an increasing responsibility in the management of resources and impacts on the regional or even global scale. Actions by a consortium of municipalities or state governments operating at larger scales are likely to accomplish even more. Partnerships across urban and non-urban places are needed, extending to address multiple global environmental issues, and the inter-connections and impacts on our planet.

Effective stewardship of ecosystem services must consider the interconnectedness of resources that link cities to ecosystems outside of city boundaries, and the multitude of actors that shape and sustain the resource flows. Urban regions must take increased responsibility for motivating and implementing solutions that take into account their profound connections with and impacts on the rest of the planet. This responsibility includes implementing the ecosystem approach of the Convention on Biological Diversity in the urban landscape and encouraging local governments to start a process for addressing the Aichi Biodiversity Targets. How this can be done is set out in the remaining key messages.

Image source: Trey Ratcliff

Global Transportation Networks

Figure 1: Global Transportation Networks
Map showing the global extent of humanity's transportation systems. Rods, railsways and shipping lanes are mostly visible.
Source: Globaïa

Human Influence on the planet

Figure 2: Human Influence on the planet
The Human Influence Index (HII) is a measure of direct human influence on terrestrial ecosystems using best available data sets on human settlement (population density, built-up areas), access (roads, railroads, navigable rivers, coastline), landscape transformation (landuse/landcover) and electric power infrastructure (nighttime lights).
Source: NASA-CIESIN-SEDAC

Global Urban Expansion to 2030

Figure 3: Global Urban Expansion to 2030
Urban land-cover change threatens biodiversity and affects ecosystem productivity through loss of habitat, biomass, and carbon storage. Although urbanization is often considered a local issue, the aggregate global impacts of projected urban expansion will require significant policy changes to affect future growth trajectories to minimize global biodiversity and vegetation carbon losses.
Source: PNAS

Urban population growth from 2010 to 2025.

Figure 4: Urban population growth from 2010 to 2025.
Source: UN