The Peril of Not Knowing What We Don’t Know

President Clinton’s global warming initiative, announced at a U.N. speech in June, has provoked a predictably negative response from many areas of government and business. The critics avoid substantive policy questions by questioning the state of research on global warming.

Concerns about the state of our knowledge are not necessarily ill-founded. Carbon dioxide, the principal contributor to the greenhouse effect, is a trace gas, constituting 0.03% of the atmosphere. Predictions of global warming depend on debatable assumptions about the effect of more greenhouse gases on clouds, water vapor, surface reflectivity and other related factors. These assumptions are contained in computer models whose validity is fiercely contested. There are respectable scientists who argue that human effects on the climate may be trivial.

The trouble is that none of this may matter. While the existence and danger of global warming may be difficult to prove, it is equally difficult to disprove. The material issue is that, without knowing what we are doing, we are conducting a planet-wide experiment in geochemistry. And this is not the only risk or even the most serious risk we are taking.

Global warming is only one of a suite of environmental effects of human activities. We are degrading the global environment through deforestation, desertification, ozone depletion, destruction of fisheries, pollution, destruction of habitat, extinction of species and many other effects similar in extent and seriousness. All of these changes are happening at the same time, and together they are much scarier than when considered one by one.

In dealing with such enormous global changes, we are confronted with the deepest mystery of life and science--that we don’t know what we don’t know.

Considered in isolation, each of the changes in the environment appears to be an incidental problem that might have a manageable solution, and it’s plausible to believe that some minor adjustments would allow us to proceed with business as usual.

Considered together as a single phenomenon, human-caused global change appears to threaten the viability of the natural systems that support life and civilization. In 1992, more than 1,500 of the world’s most prominent scientists, including a majority of the then-living Nobel Prize winners, issued a “Warning to Humanity,” which stated, “Human beings and the natural world are on a collision course.” They went on to caution that our current practices risk the future of human society and “may so alter the living world that it will be unable to sustain life in the manner that we know.”

Our political system appears to be incapable of reacting to the dilemma of environmental change. Both sides of the current political debate are preoccupied with fairness: fairness of taxation and government regulation, versus fairness of the distribution of income and benefits of the industrial society.

This preoccupation is potentially deadly, because the universe is not fair. If we humans choose to be preoccupied with our own narrow interests, the implacable forces of nature will not give us dispensation. And ignorance is neither a defense against calamity nor a license to proceed regardless. As naturalist and author Wendell Berry noted, “Though we cannot produce a complete or even an adequate description of the natural order, severe penalties are in store for us if we violate it.”

Of all our difficulties in dealing with the realities of global change, perhaps the deepest and most difficult is a conceptual one: We appear to have no place in our thinking for ordinary prudence. We need an approach to thinking about human affairs that includes all risks, including those that are currently unknown. In the past, we humans have managed our lives in the absence of certainty by allowing ourselves to be guided by principles of caution and restraint. In order to provide a conceptual home for moderation, perhaps we need a new vision of conservatism.

Understood in the absence of the ideological baggage it has acquired, conservatism is a fundamental principle of prudence and responsibility in regard to change. There are signs that this principle is resurfacing at the highest levels in connection with global warming. John Browne, chairman of British Petroleum, said recently in an interview with the New York Times that the time to act in regard to global warming “is not when the link between greenhouse gases and climate change is conclusively proven, but when the possibility cannot be discounted and is taken seriously.”

That is a prudent view, a conservative view and a model for the way we should approach our environmental situation as a whole.