from a long, but interesting, article that Greensmile alerted me to:

"Adaptation and temporal proximity also play an important role in shaping environmental policy. The Exxon Valdez oil spill in Prince William Sound in 1989 was one of the worst environmental disasters in American history, inciting a nationwide public protest, a massive volunteer effort to assist in clean up, and the passage of the Oil Pollution Act in August of 1990. Responses to subsequent massive oil spills, such as that caused by the grounding of the New Carissa in Coos Bay off the coast of Oregon, have been much more subdued and localized. The first disaster sparked widespread and vociferous response, coupled with a demand for legislation. Later disasters barely made the national news. Moreover, the Oil Pollution Act of 1990 offers a prime example of symbol over substance. The act itself focuses on establishing responsibility for spills and defining (large) fines; substantive preventive measures are vague at best. Indeed, a decade after the debacle, Exxon had yet to pay the punitive damages determined in the case and was challenging the provision of the 1990 law that forbade the specific tanker involved in the spill from ever returning to Alaska—a provision of the law that in itself is certainly symbolic rather than substantive. And finally, adaptation and a lack of temporal proximity undoubtedly play a role in the lack of world (and especially United States) mobilization to deal with the problem of global warming, which is arguably the greatest single threat to humanity (as well as other species). Unlike whales trapped in the ice, global warming is a slowly developing problem with few if any immediately identifiable victims."