Although broad scientific consensus has identified the loss of biological diversity as one of the world's most severe environmental threats, public recognition of the scale of the danger is lagging. Ecologists and other environmental scientists bear some of the blame for failing to make their concerns meaningful to ordinary people. But their challenge is made more difficult by nay-sayers who claim that fears about declining biodiversity are a tree-huggers' conspiracy to elevate Nature above people.
Nothing could be further from the truth: the threat to biodiversity can mean the loss of critical features of humanity's life-support systems, and therefore threatens our personal and economic well-being. Remedial action can no longer be delayed.
Those who maintain that the biodiversity crisis is manufactured, or at least over-hyped, often point to the sometimes exaggerated estimates of extinction rates that appear in the press. Critics seize upon these embellishments to argue that there is really not much of a problem.
Wrong. Extinctions are only the tip of the iceberg. To focus on how many species have become extinct, or will go extinct, obscures the fact that a large number of species have become greatly contracted in the range of their habitats, primarily due to human activity. We appropriate land and resources for our purposes, release harmful wastes, and introduce alien species that displace natives.
Extinct or endangered species are indicators of a much bigger problem. Little comfort can be taken in the fact that a species survives if it persists only at a fraction of its historical abundance, or if it is restricted to a narrow part of where it once thrived. Such relics may escape the graveyard of species, but they no longer provide the services to humanity that they once did. We must then find substitutes that are more costly and less satisfactory.
For example, marine fish populations that were once reliable sources of food for billions of people, and vital parts of the economies of nations, have been decimated. Many such stocks, such as Newfoundland cod, which supported huge fisheries for centuries, have been reduced to a tiny proportion of their former levels.
Salmon stocks are endangered up and down the West Coast of the US, and ecologically unsustainable aquaculture is now the major source of salmon supplies for restaurants and supermarkets. We are reducing fisheries to smaller and less attractive fish, and the situation could get much worse as those disappear.
Why care about the loss of biodiversity? Clearly, the loss of fish stocks deprives our palates, and puts parts of our food supply at risk. But much more is at stake. In natural and managed systems alike, biodiversity supplies us with food, with fiber, and with fuel. We also mine natural systems for pharmaceuticals. Indeed, the majority of commercially available drugs owe their origins directly or indirectly to the diversity of plant and microbial life. This is not just ancient history, irrelevant in the era of molecular biology: naturally derived compounds, such as taxol, still provide some of the most promising avenues for the treatment of cancers and other diseases. As biodiversity shrivels, we lose a vast store of information and potential cures.
Natural systems also provide natural purification systems for air and water, supply pollinators for agriculture, mediate our climate, and recycle the elements upon which our life-support systems depend. As we lose natural systems and biodiversity, we diminish our quality of life, threatening our existence.
So why haven't the world's peoples united to solve the problem? The answer is all too familiar. Competition among nations and among peoples trumps cooperation, and regional and global conflicts obstruct the pathways to a sustainable future. There is insufficient incentive, even at local levels, for taking the long view, and for restraining our tendency to consume in order to benefit all of humanity.
As a result, we discount the future heavily. As individuals, we ask, If others are not going to restrain their activities, why should I? Governments use the same logic, and this makes it difficult to agree upon effective biodiversity conventions to sustain vanishing resources.
For biodiversity loss, as with so many global environmental challenges, the problem is that the social costs are not captured in market prices. Human nature is such that voluntary actions, either by individuals or by nations, cannot be relied upon to lead to the essential constraints on profligate tendencies at such a large scale. So we need to tighten the feedback loops and create stronger incentives for behaviors that advance the common good, including that of future generations.
To cite one example: because Costa Rica's government pays private landowners for biodiversity conservation and other ecosystem services, deforestation rates in that country have diminished dramatically. We also need international conventions to change systems of accounting to include fully the social costs of our bahavior, as advocated by organizations such as the Stockholm-based Beijer Institute for Environmental Economics.
Incentives that reinforce practices that preserve biodiversity must be applied at all levels if they are to influence individual actions and social norms. Without collective action, we face a bleak future of disappearing biodiversity and a steadily declining quality of life.