Is it ethical to reduce our motivation for resource/wildness conservation to "ecosystem services"? Do spiritual and quality of life concerns deserve mention in policy, and is there anyway they can reasonably be useful in creating it? Or do we have to reduce everything into dollar signs because that's all large-scale deals can be made on? And supposing that we do.... do wild places become worthless as soon as we find a technology fix to replace their services?First, I refer DS and others to the discussion on ecosystem services that we had a few weeks ago.
Second, I think we need to remember that the "science" in economics is devoted to understanding tradeoffs among different choices. Put differently, economists have nothing to say (or should say nothing) when a choice has "zero" cost in terms of forgone opportunities elsewhere. Thus, we do not need to worry about a pristine ecosystem when our activities have no impact on that ecosystem.
With water, for example, there was no need to consider the impact of withdrawals (or even pollution) when the impacts of these activities were overwhelmed by the natural process. When those activities DO start to have impacts, implicit and explicit tradeoffs are being made, and economists can help people decide the "right level" of tradeoffs.
Third, everyone has their own version of "worthwhile" spiritual and/or quality-of-life tradeoffs. Economics can help reconcile different beliefs by making it possible to aggregate/trade/arbitrage among those different beliefs, to produce the "optimal" result. Of course, economics is useless if there are no markets, rights, etc. to reconcile those beliefs.
Fourth, ecosystems in one place may go away if they are replaced by "ecosystem services" elsewhere, but I am VERY skeptical of claims that such displacement is either efficient or accurate. I am not a fan of replacing wetlands or old-growth forests with man-made wetlands or tree plantations for the same reason that I am not a fan of replacing a wholesome meal with a pill that has "all the same" macro and micro-nutrients.
Bottom Line: Ecosystem services can protect ecosystems by generating revenue, but they can also distract us from the "organic" (and unquantifiable) benefits that ecosystems provide to humans and other lifeforms.