© It’s the Planet 2008

Terms of Use

Our dependence on ecosystem services

There has been much debate about what constitutes "dangerous climate change". Climatologist James Hansen suggests that it should include the extinction of animal and plant species, because this is irreversible, and climate change is already adding significant pressure on the web of relationships between species on which humanity, and all other life, depend. By focussing on ecological carbon credits - those from natural and agricultural systems which enhance biological carbon storage - It’s the Planet can help to save species from extinction as well as support ecosystem services provided by nature, which will include climate regulation.

So what are ecosystem services?  It’s easy to take them all for granted - until we try to imagine what life would be like without clean breathable air, rainfall, fertile soils, and food from the land and the sea. Ecosystem services are the processes through which natural ecosystems, and the plants, animals and microbes that live in those environments, sustain human life. Ecosystem services produce goods, such as food, timber, fibers, medicines and fuels, as well as providing life-support activities, like filtering water and recycling all kinds of wastes.

Ecosystem services are delivered by the living stuff of ecosystems - biodiversity - and their interactions with each other and the physical surroundings. The Millennium Ecosystem Assessment grouped ecosystem services into four broad categories:

• Supporting services, such as nutrient cycling, oxygen production and soil formation. These underpin the provision of the other ‘service’ categories.

• Provisioning services, such as food, fibre, fuel and water.

• Regulating services, such as climate regulation, water purification and flood protection.

• Cultural services, such as education, recreation, and aesthetic value.

Many of these ecosystem services rely on ecosystem structure and integrity. Humans have modified ecosystems more in the last 50 years than in any comparable period and as habitats become fragmented by agriculture, industry, mining and urban development, with only pockets left here and there, the services those natural systems provide become less effective. The Millennium Ecosystem Assessment (MA), a project initiated by the United Nations Environment Programme (UNEP) in 2001, set out to assess how human-made changes to ecosystems affected human welfare.  The MA found that approximately 60% (15 out of 24) of the ecosystem services evaluated (including 70% of regulating and cultural services) are being degraded or used unsustainably. If current trends continue, there is likely to be further rapid degradation of ecosystem services in the 21st century. By behaving now as if these ecosystems services are free, the costs of degrading them are being imposed on future generations.

Technology may duplicate these services temporarily, but it is doubtful that technological advances will be able to continually compensate for the large-scale loss of natural services; some services such as climate regulation may be irreplaceable. Although it is difficult to put a price tag on a wetland, forest, or river, the "price" for failing to protect or nurture these natural services could be immense. As an example, consider the response of New York City when faced with failing drinking water standards.  After exploring the technological and natural options for filtering water, New York City chose a watershed protection approach that preserves and restores nature's services. New York's $1 billion purchase of watersheds in the Catskill Mountains that purify water naturally secured precious natural habitat while eliminating the need for a filtration plant that would have cost $6 to $8 billion, plus annual operating costs of $300 million.

Is it possible to calculate the value of the products and services provided by nature? In a paper published in 1997 in the journal Nature, the annual, non-market value of the Earth’s ecosystem services was estimated at $33 trillion, substantially larger than global GDP.  This is not to say that we should only value things that we can attach a monetary value to - our respect for nature should recognise that we are sharing this planet with all the other creatures.

As we continue to populate the planet, nature's services are becoming ever more essential to humans and worthy of protection, even by those who never leave the cities.