Over the past half-century or so, a new notion has emerged, and a wonderful new term has entered the lexicon: ecosystem services. Ecologists, maybe motivated in part by the thought that you and I might be more eager to protect habitat, ecosystems, and the environment, if we knew how much they benefited us, have developed this idea.
These services are diverse. Here’s a list put out by the Ecological Society of America:
- moderate weather extremes and their impacts
- disperse seeds
- mitigate drought and floods
- protect people from the sun’s harmful ultraviolet rays
- cycle and move nutrients
- protect stream and river channels and coastal shores from erosion
- detoxify and decompose wastes
- control agricultural pests
- maintain biodiversity
- generate and preserve soils and renew their fertility
- contribute to climate stability
- purify the air and water
- regulate disease carrying organisms
- pollinate crops and natural vegetation
Whew! Pretty extensive list, isn’t it?
Other sources show somewhat different categories. Some include food production itself. [That seems like a big one! Wonder why it’s not on this list. ESA may have given an explanation, but if the did, I missed it.] Over billions of years, evolving ecosystems have played a major role in shaping the chemical composition of our atmosphere. That’s not on this ESA list, but was certainly a boon. Recreation and aesthetic services are on some lists. And don’t forget that marine ecosystems are contributors as well. Not so obvious looking at the list, but they would be implicit. Any way you cut it, the rack-up of goods and services is impressive. We owe our ecosystems a lot!
A lot? Just what is the value of such services? In 1997, the journal Nature published an article by Robert Costanza et al., that made such an estimate, arriving at a $33 trillion figure. [At the time, global GNP added up to some $18 trillion per year. [Probably the second figure in each of these numbers is insignificant.] The criticism was immediate and came from all quarters. Some characterized the paper as a serious underestimate of “infinity.” Others suggested it might be realistic to calculate the cost or benefit of say, removing or adding one acre of beach to the world’s store… that this figure would certainly be place-dependent…but that it made little sense to attempt to aggregate such figures worldwide. Some regarded the calculation as little more than a political statement. There were more objections! But in any event, Costanza and his co-authors, and Nature, for that matter, probably performed a valuable public service (in the spirit of the Darwin quote highlighted by this blog). People are taking salutary pleasure in proving them wrong. Or maybe refining the earlier ideas.
For an analog, picture aviation ten years after the Wright brothers’ first flight in 1903. Barnstormers were giving grandma a biplane ride above the farm, saying at the same time that their rickety constructs of sticks, wire, and canvas were “the people-movers of the future.” The railroads knew different. What people wanted was better linens and dining service on the Chicago Zephyr. That’s why we don’t have the Burlington-Northern or Santa-Fe airlines today.
Thinking in terms of the full-cost accounting of earlier posts, it makes sense to ask, what are the effects of our recent human success (growth in numbers, per capita use of resources, and rapid acceleration of social change and innovation)? The ESA website lists several:
- runoff of pesticides, fertilizers, and animal wastes
- pollution of land, water, and air resources
- introduction of non-native species
- overharvesting of fisheries
- destruction of wetlands
- erosion of soils
- urban sprawl
One can then estimate, and contemplate, the costs of these unintended consequences of our actions. [A cautionary note. The analysis is a little tricky because economists tell us that the loss of one mile of beachfront may correspondingly raise the value of the remaining beachfront.]