The value of our priceless environment
Our environment can be valued in many ways: for its intrinsic value, for production values, or for the many other ecosystem services it provides, from pollination to absorbing contaminants. Often how well anyone recognises that value depends on how much they identify with “the outdoors”. With nearly 85% of New Zealanders now living in cities there is increasing disconnection between people and the natural environment and a tendency to forget that we rely on it for our very being.
A seminal publication graphically demonstrates the value of the environment in dollar terms (see diagram below). While the figures are now generally regarded as underestimates of the true costs and a new body of research has produced more detailed and specific estimates, these figures have raised widespread awareness of the value of ecosystem services. What is clear from this and similar studies is that we would not be able to replace the regulating and self-generating eff ect of the environment through our own labour or technology.
Landcare Research has a growing number of staff who estimate the value of the environment, whether for its wider ecosystem services, its value for production, or in emerging markets for new forms of trading such as carbon markets. While the approaches may differ, they all help to demonstrate why we must not only understand the value of our environment but also protect it, for our own and future generations.
Source: Adapted from The value of the world’s ecosystem services and natural capital. Nature 387, p. 256, table 2, Costanza et al. 1997.
The real value of topsoil
Soil scientists and environmental economists have estimated the value of the soil organic matter in topsoil, to provide a better idea of its benefits for farmers and the whole country.
Soil organic matter, the components of soil derived from the decay of living organisms, benefits plant growth and crop production, as well as soil structure, moisture, nutrient storage and soil micro-organisms. These benefits can be masked through use of fertilisers, irrigation, pesticides and soil tillage, so the need to restore soil organic matter has not always seemed obvious. However, organic matter has recently become regarded as globally important as a significant terrestrial sink and store for carbon (C) and nitrogen (N).
Graham Sparling and Éva-Terézia Vesely estimated the extra organic matter in soils with high levels of organic matter to be worth NZ$27–151/ha/yr in terms of increased milk solids production. They found that soils depleted in organic matter took 36–125 years to recover, and the accumulated lost production was worth NZ$518–1239 per hectare. This, however, was vastly lower (42–73 times) than the “environmental” value of the organic matter as a store for C and N, which varied between NZ$22,963 and NZ$90,849 per hectare, depending on the soil, region, discount rates, and values used for C and N credits.
There is not yet a world market for the C and N storage in organic matter, but the exercise illustrates its huge contribution to environmental protection, even if we do not yet pay for or get paid for it.
Funding: FRST through the Sustainable Land Use Research Initiative New Zealand, SLURI.