Biodiversity is frequently thought of as synonymous with species diversity in wild lands, and biodiversity loss is frequently thought of as synonymous with the extinction of wild species. But biodiversity is much more than species diversity in wild lands, and biodiversity loss is much more than species extinction. Biodiversity is the variety of species used in both the production and consumption of goods and services. Examples include the ornamental plants, birds and animals that people use to enrich their lives, the variety of foods they use to enrich their diet, the mix of biofuels or biofibres used to support productive activities. It includes the genetic diversity of cultivated crops, of crop pests, of wild crop relatives, of weedy species. It includes the range of biotic disease agents that affect human, animal and plant health, and the species used to control disease such as traditional medicinal plants and the plants used as the source of modern pharmaceuticals.

Stating the problem

The Brundtland Report made a strong connection between environmental change and poverty. It argued that since poverty was both a cause and an effect of global environmental change it was “futile to attempt to deal with environmental problems without a broader perspective that encompasses the factors underlying world poverty and international inequality” (World Commission on Environment and Development 1987). The report asserted that there was a positive feedback between poverty and environmental degradation:

It also noted the coincidence between poverty and species richness in the tropics, and identified the conversion of forest to agriculture in those regions as the primary cause of the loss of wild-living species. One implication of this is that by addressing the problem of poverty in the tropics, we can simultaneously address the problem of biodiversity loss.

Preface

This book marks the end of a journey that began twenty-two years ago when I accepted an invitation from Karl-Göran Mäler, the newly appointed Director of the re-formed Beijer Institute at the Royal Swedish Academy of Sciences, to lead an interdisciplinary research program on biodiversity. That program brought together around forty social and natural scientists, and charged them with exploring the anthropogenic dimensions of biodiversity change. The results were summarized in three volumes (Barbier, Burgess and Folke 1994; Perrings et al. 1994, 1995).

They were heady times. The 1992 UN Conference on Environment and Development (UNCED) had concluded with a declaration of the intention of the governments represented there to achieve “a new and equitable global partnership through the creation of new levels of cooperation among States, key sectors of societies and people . . .which respect the interests of all and protect the integrity of the global environmental and developmental system.” The Conventions on Biodiversity, Climate Change, and Desertification were opened for signature at the conference.

Biodiversity loss and poverty revisited

My discussion of the areas in which we can, and should, collectively do better in the management of biodiversity change has so far focused on the gains we can make in efficiency rather than in equity. It has emphasized the quality of the information we generate on the nature and significance of biodiversity change, and the way we use that information to inform decisions in a world where we cannot know everything. It has distinguished between the kind of information needed to support mitigation and adaptation strategies, and the options for balancing the costs and benefits of precautionary action. It has also identified the instruments available to convert information on the effects of biodiversity change into signals to those who supply and those who demand non-marketed environmental public goods. It has not considered issues of fairness or justice. Yet our starting point – the report of the Brundtland Commission – placed issues of equity at the core of sustainable development. The Commission famously argued that: “Poverty is not only an evil in itself, but sustainable development requires meeting the basic needs of all and extending to all the opportunity to fulfil their aspirations for a better life. A world in which poverty is endemic will always be prone to ecological and other catastrophes.” It noted that the concept of sustainability necessarily implied a concern for equity between generations, and argued that the same concern logically extended to equity within generations. Specifically, it claimed that meeting the needs of this generation implied an assurance that the poor would receive their fair share of the resources required to sustain growth (World Commission on Environment and Development 1987).

Widening horizons

What do we know about the role of biodiversity in the modern world? What are the effects of biodiversity change on the two-fifths of the terrestrial system that have been fundamentally transformed by humankind? While the shape of the Holocene extinction is familiar to many – certainly to all those who work in the biological sciences – the way in which changes in species abundance and richness affect human activities is not. Most biodiversity research has focused on natural systems, and not on the role of biodiversity in supporting the production of goods and services of value to people. Research on agro-biodiversity, for example, is a vanishingly small proportion of total agricultural and forestry research. There are relatively few studies of the biodiversity in urban ecosystems, and almost no studies of the impact of changes in species diversity on ecosystem services in urban areas. The literature on biodiversity and health is primarily concerned with the role of species diversity in affecting disease transmission in natural ecosystems. The literature on invasive species is more broadly concerned with the impact of invaders on both managed and unmanaged systems, but it too focuses on the role of invaders in disrupting existing, functioning systems. The result is that we understand much about the ecology of biodiversity change, but little about its consequences for the production and consumption processes at the core of all human activity. Yet these are the things we need to understand if we are to understand directed biodiversity change.

Biodiversity, ecosystem services, and the market

For many readers of this book their first encounter with the concept of ecosystem services will have been the 2005 report of the MA (Millennium Ecosystem Assessment 2005b), and their first reaction may well have been as instinctively cautious as that expressed in 2006 by Douglas McCauley, then a graduate student at Stanford University. Writing in Nature, he characterized the approach taken by the MA as “selling out on nature”:

McCauley’s reaction was not wholly surprising. After all, the conviction that other species have infinite intrinsic value had been defined by Michael Soulé as a quintessential feature of the field of conservation biology (Soulé 1986). That conviction is one that is shared by many in the ecological sciences, and finds ready echoes in the works of the most important precursors of the field, Aldo Leopold (1949) and Alexander von Humboldt (1850).

Yet the concept of ecosystem services has nothing to do with market ideologies. Nor does it imply the commodification of nature. Some ecosystem services that are important today are certainly provided through markets. Many foods, fuels, and fibers are in this category. Other services will surely be provided through markets in the future. The identification of new pharmacologically active compounds, for example, is likely to lead to the emergence of markets for the species that are the source of those compounds. But there are many ecosystem services that are not now, and never will be, provided through markets. What the concept of ecosystem services does is to give us a way of characterizing the interests that people have in their environment. Whether an ecosystem service can be provided through the market depends on its properties, and not on the fact that it is important to people.

The unknowns in the problem of biodiversity change

In summarizing the state of knowledge on biodiversity change in both natural and managed systems the major assessments (the Global Biodiversity Assessment, the MA, the IAASTD, and the Global Biodiversity Outlook) usefully clarified the limits of our current understanding of biodiversity change. They showed that our knowledge is still extremely patchy. We know much about changes in species richness and abundance for birds, for example, but little about many invertebrates. We have many data on the ecological consequences of biodiversity change in temperate grasslands, but relatively few on tropical forests. At the same time none of the assessments offers much insight into the value of one type of biodiversity change relative to another. In the opening chapters of Part II of this book I have considered what this means for the information needed to underpin management of biodiversity change. Chapter 8 considers the information requirements of the main management options, adaptation and mitigation, and what this means for the way we project the causes, consequences, and character of biodiversity change. In Chapter 9, I address the issue of valuation, and the challenges involved in generating information that can inform macro-economic policy.

In the best of all worlds, however, we will still be called on to make decisions on the basis of incomplete information. There are two dimensions to the problem of biodiversity change that complicate both calculation of what it costs society and development of options for its management: the irreversibility of some aspects of biodiversity change and the fundamental uncertainty that induces. For all practical purposes the extinction of species is forever. Its effects are unknown and unknowable at the moment it occurs. People undertaking activities that change either the survival prospects of a species or its range cannot imagine all possible consequences of their actions. Nor are they able to assign probabilities to the consequences they can imagine. Similarly, it is not possible to reverse the changes wrought by many invasive species, or to assess the potential costs and benefits of actions that irreversibly affect the future evolution of the system.

The search for solutions

Sustainability and stability

There has been a burgeoning interest in the sustainability of many current trends – consumption, economic and demographic growth, and environmental change among them. While the origin of the term sustainable development is usually given as the report of the Brundtland Commission, Our Common Future (World Commission on Environment and Development 1987), its roots lie much deeper than that. One of the main precursors to the Brundtland Report, Herman Daly’s Towards a Steady State Economy (Daly 1973), directly appealed to John Stuart Mill’s mid-nineteenth-century thoughts on the stationary state. Mill saw a less growth-oriented strategy as the key to preserving at least some part of the natural environment (Mill 1909). Yet to do no more than maintain average incomes in many developing countries aggregate income is required to grow at rates up to 3.5 percent a year (i.e. to match the population growth rate), and increasing average incomes requires aggregate income to grow at rates above that. As Malthus had observed at the close of the eighteenth century, the consequences of failure to maintain average incomes have historically been severe (Malthus 1999). The challenge given to the global community by the Brundtland Commission was not just to avoid Malthusian crisis through the degradation of the resource base, but also to eliminate poverty worldwide.

The Brundtland definition of sustainable development – “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” – refers to the capacity of a system to maintain a flow of services over time (World Commission on Environment and Development 1987). This is a systems-level property that implies something both about system stability and about the value of system assets over time. What matters for the Brundtland definition is the capacity of the system to continue to deliver benefits over the expected range of environmental conditions.

Diagnosing the biodiversity change problem

Everyone in the world depends completely on earth’s ecosystems and the services they provide, such as food, water, disease management, climate regulation, spiritual fulfillment, and aesthetic enjoyment. Over the past fifty years, humans have changed these ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, freshwater, timber, fiber, and fuel. This transformation of the planet has contributed to substantial net gains in human wellbeing and economic development. But not all regions and groups of people have benefitted from this process – in fact, many have been harmed. Moreover, the full costs associated with these gains are only now becoming apparent (Millennium Ecosystem Assessment 2005c).