Measuring the unmeasurable
ARTHUR LYON DAHL
examines different forms of sustainability and proposes
a way of tracking progress towards them
Sustainable development has become the catchword of our
decade, used and misused in many contexts. Yet it has been notoriously
difficult to define. It implies a central focus on people. Our society, of
course, functions in a natural environment. But we are seeking the
sustainability of human society as it depends on, and intimately
interrelates with, natural systems. This may be seen as anthropocentric
but, in the present context of the international debate on development and
equity, any other approach could be considered morally indefensible.
The concept of sustainability
In a dynamic system like human society, sustainability is fundamentally a
question of balance, maintained over time. It thus cannot easily be scaled
and measured, since it is a quality of motion rather than a fixed point.
It may be more easily defined, in practice, as the lack of forces tending
to upset an equilibrium over time. This is why most indicators are in fact
measures of unsustainability, of the amount or extent of imbalances. As
with a moving pendulum or an aircraft in flight, many different forces can
act simultaneously to disturb an equilibrium; if one is reduced or
eliminated, others become predominant. Sustainability can only be achieved
when all forces upsetting the balance are removed.
Being dynamic, sustainability includes such characteristics as the speed
or rate of change, the size of the mass involved in the change and thus
the inertia of the process, and the significance of the amount and rate of
change relative to the initial and resulting states. For instance, when
determining the sustainability of a renewable resource harvest, it would
be important to know the amount harvested, at what rate, over a given
period, relative to the total stock of the resource at the beginning and
end of the period, and the simultaneous rate of resource regeneration.
In any community or economic system, there can be many sources of
unsustainability, such as the limited size of a resource, inadequate
supply inputs, excessive demand for outputs, and damaging pressures such
as pollution. Some of these may be controllable within the system, while
others are subject to outside pressures. Since most systems are complex
and not well understood, cause and effect relationships are not always
apparent. The challenge is to find simple ways of presenting this concept
despite the complexity and uncertainty.
While planners and politicians tend to look only five years ahead - and
see the long term as 20 years - it would seem reasonable in the context of
global systems and resources to view sustainability as stretching into the
indefinite future - say, up to half a million years - as a time span over
which our actions should not constrain future society. This would help to
avoid the tendency to discount the long-term future, and would require
adequate consideration to be given to fundamental, if gradual, processes
of global balance and change.
The dimensions of sustainability
There are as many potential dimensions to sustainability as there are
important dimensions of any human society. Accountants think in terms of
fiscal sustainability, where deposits plus interest must balance
withdrawals plus charges. A financial debt is a constraint imposed on
future ability to meet needs; it is unsustainable to the extent that the
present advantage procured is insufficient to reimburse the debt.
Economists have a slightly broader view of sustainability which includes
the maintenance of assets and capital value and productivity through
investments at least equal to depreciation.
There is much concern over the ecological sustainability of
human development, with population growth and resource consumption drawing
down stocks of natural resources and their renewable potential, while
increasing wastes damage natural systems and upset essential life-support
processes. We are accumulating resource and pollution debts that can only
be eliminated through extensive future investments. Many ecological
processes are so complex and so poorly understood that it will be very
difficult to derive indicators of ecological sustainability: at best we
can use indicators of unsustainable pressures and impacts which should be
minimized in a precautionary approach.
While there are now some indicators of human development, we have not yet
really touched on what might be called human sustainability. People
need education and training to develop their potential to become
productive members of society. This is an investment like any other, and
the poverty that results from the failure to make it is just as much a
debt as a financial one, representing a burden of wasted potential
weighing on the future. Since life-spans are limited, educational
investment in individuals is ultimately depreciated and lost. Human
sustainability thus includes the educational and cultural processes that
preserve human knowledge and ensures its transmission between generations.
Can we indicate whether a generation knows more than a preceding one?
Scientific and technological knowledge may be increasing, but other kinds
of knowledge and experience are being lost.
Dimensions that could be referred to as social sustainability may
be just as crucial to what we should define as development, but have
largely escaped existing systems of measurement and accountability. A
developed society, for instance, has an elaborate legal system, built up
over generations of legislative additions and judicial interpretations.
This is also an investment in what should be considered an important part
of national wealth, if only judged by its replacement value. Yet societies
change and laws are dynamic. Can we measure how well a legal system is
meeting social needs? Communities are structured into institutions ranging
from government bodies through corporations to informal associations and
religious organizations. Do we have measures of the effectiveness of this
social structuring, its processes of communications and decision-making,
and their evolution over time? Is social cohesion increasing or
diminishing?
This could be extended to moral, ethical or spiritual
sustainability. An effective society depends on a shared set of values
or ethical principles that define acceptable behaviour, and motivate
people to work together in the common interest. As the basic rules for
human interaction, these are an essential support to development. A
society that is losing its moral core may appear materially successful
before declining into anarchy. In theory, at least, this should be
included in a broad concept of the sustainability of human society, even
if the practical problems of developing indicators are daunting.
The temporal dimension
Any comprehensive approach to indicators for sustainable development must
include both new kinds of indicators and new ways of accounting for
sustainability over time. Any measure of balance cannot look only at the
static situation at one moment, but must examine measures integrated over
time to document processes and trends. Such accounts should include past
trends leading up to the present, and projections of what will be needed
to achieve or maintain sustainability in the future. Present economic
balance sheets are thus doubly flawed: they exclude many capital stocks
and flows as externalities, and they are not adequately summed over time,
particularly with respect to future implications of the current situation.
Nothing is permanent on this planet. Wealth is created and destroyed;
energy is degraded; materials are concentrated and dispersed; useful
information is increased and lost; things wear out; objects and materials
have a useful life and then become wastes; old technologies are replaced
by new ones. Aging and death are as much part of life as reproduction and
growth. Sustainability requires accounting for all this over time. For the
ultimate balance to be sustainable, the processes of maintenance,
replacement and renewal must equal or exceed the process of depreciation,
degradation and loss.
We cannot automatically assume that capital replacement will take place.
This requires investment, and may have preconditions which have to be
taken into account. We can make some reasonable assumptions for people now
alive - disallowing the possibility of cataclysm - but can we be so
certain about future birth rates? What, for instance, if some common
pollutant caused widespread sterilization? Can we assume the maintenance
of agricultural productivity if soils are eroding, new diseases are
evolving, the genetic resource base is shrinking or being privatized, and
research is declining, so that the necessary investments to maintain
productive potential are not being made? Industry may invest in a factory
with a 30 year productive life, over which its depreciation is calculated
and its potential profits determined - but if a new technology makes the
product obsolete in five years, 25 years of investment will be lost.
Any accounting system for sustainability must be able to spot failures to
reinvest, damage to future productive potential, and the resulting impact
on integrated total productivity over time. This requires accounts that
show all existing investments, capital stocks and productive capacity, and
the present rate of production (often well below the peak capacity). They
should incorporate projected depreciation, and necessary investments for
maintenance, renewal or replacement. Technological innovation and its
impact must be modelled, insofar as there are rational bases for
predicting it. An integrated accounting methodology should try to take
into account all significant interactions, such as damage caused by one
activity (say pollution from industry) on another (like agricultural
production). It should include available skills and knowledge, and their
replacement as generations change.
Such integrated accounting over time should help to eliminate unrealistic
assumptions about the future, by incorporating the real dynamics of
possible rates of change and the capacities of such systems and resources
as water, primary productivity, available land area, and population size
and density. Energy throughput, from both renewable and non-renewable
sources, will be one critical factor. The sum of the dynamic indicators
for the movements over time of all these dimensions of our total accounts
will begin to define real sustainability.
On this basis, some industrialized, 'developed' countries may show
frighteningly unsustainable accounts, demonstrating that their prosperity
is based on heavy borrowing from future potential, or relying on highly
optimistic assumptions about technological replacements which will require
difficult and expensive industrial and social transitions.
Beyond sustainability to sustainable
development
We will need to distinguish between various kinds of economic activity and
the wealth they create if we are to begin to address sustainable
development. We need measures of what might be called real or 'strong'
development, as compared to simple economic activity or gross national
product (GNP). Transfers or redistributions from one account or place to
another do not themselves create wealth: they may represent equal
exchanges, or increasing wealth compensated by a corresponding increase in
poverty. Harvesting bananas cheaply in Central America and delivering them
to a European table may raise their price, but does not really generate
wealth: the price increase just reflects the transport, storage,
middle-man costs and increased profit margin. The intrinsic value of the
bananas for nutrition is the same; only the scarcity and
willingness/ability to pay have changed with the location. Real value
added comes from primary productivity or from transformation or processing
to add functionality, utility, durability, or other kinds of information
content. To determine real value, every cost and input should be accounted
for, and hidden subsidies in production should be avoided.
Maintaining capital is also neither wealth creation nor real development -
but running in order to stand still. One does not become wealthier by
replacing a leaking roof, filling potholes in the street, washing dishes,
cleaning up pollution, or buying a replacement vehicle. Real development
is when new value is added by innovation or creation, the quality of life
is increased, or a larger net mass of goods and services is produced and
maintained, after all the costs of production and depreciation have been
subtracted. This will probably be both a much lower percentage, and
involve different kinds of growth, than that measured using today's GNP
indicators.
This net approach to growth may have important implications for national
interest rates and thus for calculations of sustainability. The real rate
of interest on capital should probably not exceed the real rate of
creative wealth it generates. Most of what goes into today's interest
rates and rates of return on investments are 'growth opportunities' that
either compensate for inflation or represent hidden resource transfers and
subsidies produced by failures in true accounting. They come, for
instance, from treating natural capital resources as externalities or from
exploiting poorer countries or social groups.
The present economic system of accounting and indicators has produced a
financial system which manufactures money as a commodity, through credit
mechanisms that allow cumulative borrowing and reborrowing, aided by
banking and accounting delays and manipulations. As money circulates,
particularly through electronic accounts, it multiplies by the play of
interest rates and layer upon layer of debts in more and more compartments
of the system: government debt, corporate debt, consumer debt, resource
debts, etc. Does the present system of accounts add up all those debts
across the whole society and place them against net assets valued over
time? Does it identify real wealth creation, investment and maintenance
rates as compared to debt, depreciation and resource draw-down rates? Are
there indicators for all the key components in this process? Complex
issues like these must be faced if indicator systems are to approach the
real nature of sustainable development.
The varieties of sustainable development
Some developing countries and cultures suspect that environmental and
sustainable development indicators will be used to force Western values on
them or to impose conditionality. This is aggravated because indicators of
sustainability need to be evaluated against some target or limit. Yet
setting these involves value judgments that are inherently culture-bound.
If they are to be relevant worldwide, indicators of sustainability must be
designed to have sufficient flexibility to measure common themes,
dimensions or trends while remaining universally culturally appropriate.
They should be capable of covering the full spectrum from the
'superpowers' to the small island developing states, from indigenous
subsistence to postindustrial communities, from high-tech to no-tech
situations.
There may be an objective scientific basis for setting targets or limits
for environmental indicators, such as the level of pollution causing
health effects, the reduction in chlorinated compounds necessary to
protect the ozone layer, or the amount of forest cover needed to maintain
a particular level of water flow in a catchment. At least science can
define a gradient of environmental quality along which each society can
set its appropriate limit. However, limits or targets are much more value
laden on the social and economic side: indicators cannot be absolute but
must relate to each society's concepts, goals and values. They can only be
decided within a country or culture, preferably on the basis of wide
consultation and participation. Thus the concept of international
performance indicators for sustainable development is, at least at
present, politically unacceptable. States do not want anyone else judging
their performance or the way they define development, and they want to
choose how to report their progress.
Indicating sustainability
One way to express the concept of sustainability without falling into
value judgments about development would be to produce 'vector' indicators,
showing the direction and speed of movement toward or away from a goal.
These would allow each country to define how it imagines its ideal future
sustainable society (an instructive exercise in itself), and then to
report, for each indicator, whether it is making progress towards its own
goal, and at what rate. A country could, for instance, determine its
optimal population, calculate the growth curve necessary to stabilize
numbers at that level, and then measure the deviation of its actual
population curve from that needed to reach its target. A policy maker
could thus see immediately whether the trend was in the right direction,
and how long it would take to achieve the desired result. The national
goals or targets so set would need to be flexible and subject to change as
technological possibilities, new discoveries and social visions changed.
Vector measures would also allow countries to report progress in reducing
damaging activities, even if they had not yet defined clear goals for
sustainability.
The concept of sustainability as a process of balance can also help to
determine the relative weight given to different indicators. Indicator
values can be ranged on a non-linear scale, where more extreme problems or
larger deviations from the desirable level carry more weight than small
ones. This weighting should be calculated according to the specific
characteristics of each phenomenon (indicators
diagrams). A pollution indicator might have no significance at low
concentrations, might rise somewhat as moderate levels affected amenity
values, and then increase sharply as the pollutant harmed health at high
concentrations. Similarly, depleting the first 5 per cent of a resource
may have little significance, while depleting the last 5 per cent may have
enormous impact. There may be an optimum indicator level, with deviations
in either direction becoming increasingly harmful. One extreme problem may
be much more threatening to sustainability than many minor ones. Using
such non-linear scaling can facilitate rational aggregation of indicators
by providing a more objective criterion for relative weighting than an
arbitrary combination or equal treatment. Each indicator, in effect,
weighs itself according to the significance of its impact.
We should try to develop standard graphic forms to plot indicators of
sustainability. Several characteristics need to be incorporated into such
plots to illustrate how the idea of sustainability can be communicated
(see trajectories, right).
First, the particular target that has been set locally should be combined
with a projection of the planned or preferred trajectory of the indicator
to reach it at the agreed time. If this trajectory to sustainability is
agreed in the planning process, it will help decision makers to visualize
the commitment they are making and the effort needed to achieve their
goal. It will then be possible to plot the deviation of the actual
situation or location of the indicator relative to the projected level or
trajectory. This could be a deviation both in the value of the indicator
(above or below the target) and in its vector - whether it is moving in
the right or the wrong direction, and at what speed. It is the direction
and speed of the indicator vector as well as its location that really
begin to define sustainability as a dynamic concept. They should be scaled
or weighted in value according to the importance of the deviation. The
critical points in these trajectories that will be of the greatest
interest to policy makers, are the points where the indicator vector is
changing (whether it is slowing down, speeding up, changing direction), as
it is these changes that signal the effectiveness of whatever actions have
been taken. Such trajectories and their vectors quickly show if management
actions are sufficient.
Standard ways of expressing sustainability indicators should be agreed as
far as possible, to make them easily understandable and widely
recognizable. They could be developed not only as numbers and graphic
representations, but also on scales and even colour codes. Indicators
could be scaled as a percentage ranging from 100 for full sustainability
to 0 for total unsustainability or collapse. Another measure could be the
number of years to achieve sustainability (for positive trends) or
absolute unsustainability (for negative ones). A colour scale could range
from white for full sustainability through yellow and green for
improvement and violet and red for degradation to black for collapse.
Arrows or other symbols could communicate vector indicators.
Sustainability may be a complex concept, but its indicators could still
have a direct meaning for everyone.
Indicators of sustainable development are being pushed by political demand
despite the hesitancy of experts and scholars to tackle questions that
involve human values and political processes as much as or more than
specific methodologies. We must rise to the challenge and work to develop
indicators that can themselves become the driving forces towards a truly
sustainable society.
Arthur Lyon Dahl is UNEP's Deputy Assistant Executive Director,
Environmental Information and Assessment.
