Why Should an Urbanist Care About Biodiversity?

Olivier Scheffer, Paris. 
November 27, 2016

Many voices. Greener cities. Better cities.

Let’s face the facts.

Despite laudable international initiatives for climate change mitigation and environmental preservation [i], major changes in Earth’s balances have been set in motion and we’re starting to experience their consequences: heat records; increased droughts; increased wildfire intensity and frequency; melting of landlocked ice; increased sea level and coastal storm damages; ocean acidification; climate change-based migration flows of human and animal/insect populations, along with pathogens and diseases—without considering the great loss in biodiversity, where one animal or vegetal species disappears every 20 minutes.

Habitat loss is the main cause of biodiversity loss, and a main cause of habitat loss is land use change due to urbanization and transport infrastructure.

Indeed, when the debate is focused on “energy efficiency” and “greentech”, we’ve almost forgotten one major threat for human survival: the survival of all the other inhabitants of our planet. According to the International Union for Conservation of Nature, the extinction rate is between 100 and 1,000 times greater than during the 65 million (!) previous years. As a result, 26,000 (known) species disappear each year, and according to the Living Planet Index 2014 [ii], “population sizes of vertebrate species—mammals, birds, reptiles, amphibians, and fish—have declined by 52 percent over the last 40 years”; that measure is up to 76 percent for freshwater species. According to the IUCN, the picture isn’t rosy for the near future: 25 percent of mammals, 13 percent of birds, and 41 percent of amphibians will disappear in this timeframe, adding to 37 percent of all known species by 2050.

Figure 1. The Global Living Planet Index is based on trends in 10,380 populations of 3,038 vertebrates (mammal, bird, reptile, amphibian, and fish species). The white line shows the index values and the shaded areas represent the 95 per cent confidence limits surrounding the trend. Image: WWF, ZSL, 2014

Why should you care, if you’re not an enthusiastic nature conservationist?

For three reasons at least:

Firstly, species—from bacteria and viruses to mammals, including humans—are part of the “web of life”, as Fritjof Capra [iii] writes it. “These are the living forms that constitute the fabric of the ecosystems which sustain life on Earth”, says Marco Lambertini, WWF’s International Managing Director.

See also this, on biomimicry as a key path forward.
Life is not the simple addition of all 10 million species: it is their intricate relationships, which form the fabric of ecosystems. On a vertical axis, the food chain—where, for example, ocean acidification is depleting plankton populations to the extent that the whole trophic chain, up to large aquatic mammals and fisheries—is endangered. On the food chain’s horizontal levels, the myriad collaborations that take place—starting in the soil, where thousands of species, such as mycelium and bacteria transform rock and digest dead organic matter, including human pollutants, into a rich earth—form a process that, over 700 or so years, creates 1 cm of soil. Yet, that creation can be destroyed in a few hours by deforestation or new built infrastructure.

On a global level, where all those interactions add to biochemical and geochemical cycles (such as the nitrogen, water, carbon, oxygen, and phosphorus cycles), they have historically maintained the delicate balance of Life. Therefore, biodiversity, from genes, to species, to ecosystems, is paramount to the presence of life on our planet, and to our own survival, notably through all the ecological services it provides [iv].

Despite our great effort to disconnect ourselves from the “web of life”—to the extent that we are investing billions into inventing artificial life-support systems for space exploration—we, human beings, continue to be inextricably tied to this web of life.

Secondly, because we human beings are the main threat to biodiversity and our environment, so, therefore, are we our main threat to our own survival.

Indeed, the primary explanation for biodiversity loss, according to the Living Planet Index, is the degradation, fragmentation, or loss of natural habitat (45 percent), followed by the over-exploitation of resources (37 percent) and climate change (7.1 percent only). Habitat loss is identified as a main threat to 85 percent of all species described on the IUCN’s Red List. Habitat loss is mostly caused by the expansion of agricultural land; intensive harvesting of timber wood for fuel and other forest products; and overgrazing. “Around half of the world’s original forests have disappeared, and they are still being removed at a rate 10x higher than any possible level of regrowth. As tropical forests contain at least half the Earth’s species, the clearance of some 17 million hectares each year is a dramatic loss”, says the Living Planet Report 2014.

But the second main cause for habitat loss is land use change due to urbanization and transport infrastructure. We’re generating a quantity of artificial soil as big as the area of Greece every year. In the European Union alone, such land use change represents 1,000 km2 each year, or 275 hectares per day [v], of artificial soil—the equivalent of Central Park in New York City, or the area of Hungary within one century. Alongside urbanization comes air (and also sound and light) pollution, accounting for 4 percent of biodiversity loss.

The Global Ecological Footprint [vi], published each year by the Global Footprint Network, is a very clear and understandable signal measuring our pressure on our planet’s resources and “biocapacity”: we are using more natural resources than our natural environment can provide, and we would need 1.5 Earths to fulfill our consumption needs (and up to 4 Earths if we all had the living standards of U.S. citizens).

Figure 2. Global ecological footprint evolution and Earth Overshoot Day forecasts. Image: Global Footprint Network (2016)

With the phenomenal growth of the world’s population, which has added 2 billion people since 1990 and is expected to add 4 billion more by 2100 (3 billion for Africa alone); with the growing concentration of this population in urban areas (from 30 percent of the global population in 1950 to 66 percent by 2050), especially in Africa; with the rise of new economies; and with developing countries seeking the average standards of living in the West, the pressure on our planet is not going to ease.

Figure 3. Countries by Real GDP Growth Rate (2014). Image: https://en.wikipedia.org/wiki/List_of_countries_by_real_GDP_growth_rate

Experts believe we entered the Anthropocene epoch in the mid 20th century, and our planet is paying the price. As the climate experts from the IPCC noted in their 2007 synthetic report: “Unmitigated climate change would, in the long term, be likely to exceed the capacity of natural, managed, and human systems to adapt. (WGII 20.7, SPM). This description does not even name the biodiversity loss and nitrogen cycle threats that are identified by the Stockholm Resilience Center as the major Earth boundary overshoots, out of ten such factors.

Figure 4.The Planetary Boundaries. Image: Stockholm Resilience Centre (2009)

To put it more directly, we’re heading toward the wall at full speed, still wondering and discussing how we can slow down; we now have to prepare ourselves for damage (crash?) control, as well as resilience (survival?).

Thus, the third reason we should care about biodiversity is that it might be the solution to our problems. See my next post for details on how using biodiversity could help us achieve sustainability and resilience.

Olivier Scheffer

On The Nature of Cities

For more information on this subject, read:

“Ecomimicry: Reconnecting Cities—and Ourselves—to Earth’s Balances” on TNOC.


[i] the latest being the Paris Agreement at the COP21 – if ratified by 55 countries representing more than 55% of GHG emissions

[ii] “Living Planet Report 2014” from the WWF, the Zoological Society of London, The Global Footprint Network, The Water Footprint network http://www.worldwildlife.org/publications/living-planet-report-2014

[iii] http://www.fritjofcapra.net/books/

[iv] The United Nations Environment Programme made this very clear more than 10 years ago in its Millennium Assessment programme : supporting services (nutrient recycling, primary production, and soil formation), provisioning services (food, raw materials, minerals, water, energy, genetic, and medicinal resources), regulating services (climate regulation; carbon sequestration; waste decomposition and detoxification; purification of water and air; pest and disease control), and cultural services (recreational, therapeutic, educative, historical, spiritual).

[v] « Lignes directrices concernant les meilleures pratiques pour limiter, atténuer ou compenser l’imperméabilisation des sols », Services de la Commission Européenne (2012)

[vi] http://www.footprintnetwork.org/en/index.php/GFN/page/world_footprint/

Olivier Scheffer

About the Writer:
Olivier Scheffer

Olivier Scheffer is Deputy Managing Director at NOBATEK/INEF4, a board member of the French Committee of Biomimicry Europa, and a bio-inspired habitat adviser to the CEEBIOS.

3 thoughts on “Why Should an Urbanist Care About Biodiversity?

  1. Good article.

    I always find this is an interesting topic, but it strikes me an important aspect of this discussion is always missed and my argument runs generally along these lines:
    *no water on the moon > no life on the moon
    *little water in the desert > little life in the desert
    *there are some papers I’ve found supporting increased bio masses in riparian and wetland environments
    1. Wet and damp landscapes are more biologically productive than dryer landscapes;
    (a) if they are are ecologically viable
    *water flows down hill
    *the bottom of the hill for our purposes here is sea-level
    2. most wetland environments occur at, or near sea-level
    (a) this water reaches these wetlands along riparian river corridors.
    3. We have built most of our cities, and most of our population live in and over ‘urbanised’ wetlands and thier supporting riparian corridors.
    4. the best way to support bio-diversity, in cities, is to start reintroducing water, lots of water, embedded in it’s natural flow regime because:
    5. You cannot (for all sorts of reasons) produce wetlands and riparian corridors somewhere else, it has to be where the water ends up. Given we are confronted with gradual inundation anyway, what better time to get on with the job of confronting the key task of planning, reintroducing large scale natural process into our urban fabric. *you just can’t build a coastline of viable swamps, wetlands and riparian systems ‘somewhere else’!
    I just sometimes wonder if it is me overstating or over thinking these matters, or if (I’m still a student) we, as city professionals, are ignoring what to me seems so bleedin’ obvious.
    I really hope I’m wrong on this, I want to be wrong on this, and I hope someone can explain to me why and how we can substitute high productivity damp environments displaced by cities, with ‘something’ else and achieve the necessary biotic productivity to support diverse, and by extension, sustainable ecosystems?

  2. Absolutely!
    There is so much biodiversity in cities now and having biodiversity in cities brings benefits.
    Additional biodiversity often comes into cities on the back of Green Infratstructure investments.
    Green Infrastructure is a network of green spaces that provides multiple social, economic and environmental benefits. It can play different roles in rural and urban areas. It is well recognised in the US and Europe. In the UK it is well established in planning policy (but often still poorly implemented).
    Green Infrastructure (of which biodiversity is par tof) then brings benefits for air quality, noise management, mental & physical health through access to natural greenspaces, flood risk management and so on.
    Dr Ingo Schuder, Oxfordshire, UK.

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