What do thalidomide, asbestos, PCBs (polychlorinated biphenols), nuclear waste, depletion of international fisheries, and climate change have in common? They are serious public health and/or environmental problems with some common elements in their histories. In every case, activities undertaken for good reasons – to serve demands that were genuine, to reduce costs or keep them low, and in the process to raise standards of living – led eventually to enormous damage and expense, or the prospect thereof. What went wrong? After all, our societies were not born yesterday. They are aware of the risks posed by innovation, resource exploitation, and overstressing our environmental systems, and they maintain institutions to assess risks and regulate potentially harmful activities. Yet, these institutions failed quite clearly to prevent or minimize the potential harm.

In each of these cases, the standard approaches to risk management failed in several or all of the following ways: they did little to prevent the threat; were slow to diagnose it; tolerated far too much dispute about harm and cause before taking action; and acted only after the problem was obvious, widespread and built into the economy, society, and way of life, so that remedies were enormously expensive and relatively ineffective. Because remedies were implemented too late to forestall the damage or restore the status quo ante, they necessarily were focused more on remediation, mitigation, and adaptation.