GUEST BLOG: How do you hold a sunbeam in your hand? Valuing the invaluable.

13th August 2014 By Deborah Long

Yellowdrop milkcap. Use in the past as an insecticide against bedbugs and with unknown future uses. © E. Holden.

How do you value a sunbeam? By measuring the light levels? The heat generated? The amount of photosynthesised energy produced? The amount of biomass created?  

How do you value a fungus? By measuring whether it is producing mushrooms or not? By counting the number of plants dependent on it? By measuring the amount of debris that would accumulate if it wasn’t there?

How do you value native woodland? By how much timber and non-timber forest products it produces? By the number of sick days averted as people use it for exercise?  By the amount of clean air it produces? Or clean water?

All of these values are real. Some are more measurable in terms of cost than others – but what is obvious is that all these ‘ecosystem services’, which flow from a healthy stock of natural capital, are important to us all and that managing without them would be difficult to say the least.

How then do we value and protect them for future generations? The assumptions behind natural capital accounting work for some of them. We can model how much clean air woodland produces, how much flood protection a functioning peat bog provides, how much clean water a mountain produces. That is the relatively easy bit. What is more difficult is taking account of the net value of entire ecosystems. Ecosystems are complicated. Robust ecosystems are even more complicated. A robust ecosystem is one that retains its full species and habitats diversity. Within this diversity are species that hold the future cure for common and rare diseases, species that work away providing a vital function that we haven’t even noticed yet, and species upon which other species depend, whose collapse would cause a tidal wave of changes and extinctions.

How do we value these unknown benefits that we’ll maybe understand in a few years time? How do we value flowers that we want future generations to experience in the wild instead of just in gardens? How do we value the fungi that support 80% of our timber producing trees?

The best policy tool we have today is the precautionary principle. Aiming to conserve the maximum diversity of our ecosystems at least ensures that they can continue to provide all these benefits we haven’t yet understood or even noticed and avoids exploring the new and unknown territories of ecosystem tipping points. Until someone works out how to cost the unknown benefits we are all dependent on today, just attaching value to the benefits we already know about looks extremely short-sighted.

Let’s apply some of the lessons being learnt by the insurance industry as they work out how to cost up uncertainty. By applying logarithms on the cost of uncertainty and change, we can at least start to identify where our knowledge gaps exist. To date, society’s seriously limited approach to understanding the importance of natural capital has not looked up to see the potential changes that are looming if we continue to lose biodiversity, and the ecosystem resilience it supports.

While a new approach may not help us hold a sunbeam, it may at least ensure that future generations will be able to experience its warmth.


Dr Deborah Long (@DeborahLong) is Head of Plantlife Scotland & Chair of Scottish Environment LINK. Plantlife Scotland & Scottish Environment LINK are both members of the Scottish Forum, you can see the full list of members here.

Click here to read a selection of quotes from members explaining why they have joined the Scottish Forum.