Dr. Jane Lubchenco, a marine ecologist from Oregon State University, has been elected to many scientific honors, one of which was the presidency of the American Academy for the Advancement of Science. For her presidential address at the AAAS annual meeting, she looked straight out at the huge assembly of scientists and delivered an unapologetic, undiluted warning:

“During the last few decades, humans have emerged as a new force of nature. We are modifying physical, chemical, and biological systems in new ways, at faster rates, and over larger spatial scales than ever recorded on Earth. Humans have unwittingly embarked upon a grand experiment with our planet. The outcome of this experiment is unknown, but has profound implications for all of life.”

What responsibility do scientists have, she asked, both to transmit this message and to help deal with the problem?

Actually scientists, and others, have been transmitting similar messages lately with clarity and urgency. Here are just a few excerpts, from a long and growing list:

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World Resources Institute, 1998: “Most high-quality agricultural land is already in production, and the environmental costs of converting remaining forest, grassland, and wetland habitats to cropland are well recognized. … Much of the remaining soil is less productive and more fragile. … One analysis of global soil erosion estimates that … topsoil is being lost 16 to 300 times faster than it can be replaced.”

International Food Policy Research Institute, 1999: “The period since World War II has seen remarkable growth in agricultural production … in the developing world. While in many farming areas this growth has apparently been sustainable, in others it derived from two unsustainable processes: the clearing of new lands of lower productive potential or higher vulnerability, and the intensification of production by mining or destroying the soil resource base.”

U.N. Comprehensive Assessment of the Freshwater Resources of the World, 1997: “Water resources constraints and water degradation are weakening one of the resource bases on which human society is built. Water shortages and pollution are causing widespread public health problems, limiting economic and agricultural development, and harming a wide range of ecosystems. They may put global food supplies in jeopardy and lead to economic stagnation in many areas of the world.”

World Commission on Forests and Sustainable Development, 1999: “There has been a clear global trend toward a massive loss of forested areas. … The current trends are toward an acceleration of the loss of forested area, the loss of residual primary forests, and progressive reduction in the internal quality of residual forest stands. … Much of the forest that remains is being progressively impoverished, and all is threatened.”

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World Scientists’ Warning to Humanity, 1992: “Our massive tampering with the world’s interdependent web of life — coupled with the environmental damage inflicted by deforestation, species loss, and climate change — could trigger widespread adverse effects, including unpredictable collapses of critical biological systems whose interactions and dynamics we only imperfectly understand. Uncertainty over the extent of these effects cannot excuse complacency or delay in facing the threats.”

Two oil industry geologists, Colin J. Campbell and Jean H. Laherrère, sobered everyone by saying in Scientific American in 1998: “Our analysis of the discovery and production of oil fields around the world suggest that within the next decade, the supply of conventional oil will be unable to keep up with demand. … Global discovery peaked in the early 1960s and has been falling steadily ever since. … There is only so much crude oil in the world, and the industry has found about 90 percent of it.”

Another industry voice, Robert Shapiro, CEO of the Monsanto Corporation: “The earth can’t withstand a systematic increase of material things. If we grow by using more stuff, I’m afraid we’d better start looking for a new planet.”

Economists are speaking up as well. The following statement was signed by 2000 economists, including six Nobel laureates, in 1997: “The balance of evidence suggests a discernible human influence on global climate. As economists, we believe that global climate change carries with it significant environmental, economic, social, and geopolitical risks, and that preventive steps are justified.”

Ecological Society of America, 1991: “Environmental problems resulting from human activities have begun to threaten the sustainability of Earth’s life support systems.”

The [U.K.] Royal Society and the [U.S.] National Academy of Sciences, 1992: “The future of our planet is in the balance. Sustainable development can be achieved, but only if irreversible degradation of the environment can be halted in time. The next 30 years may be crucial.”

Short of yelling and screaming, which scientists are trained not to do, I don’t see how these august people could be more clear. None of their reports concludes that there is nothing to be done, that we must stupidly submit to the consequences of our overconsumption of our own resource base. They are full of constructive, common-sense, affordable, doable suggestions by which human needs could be met without destroying the planetary sources that maintain us.

The scientists are doing their part. When will television start harping on major tragedies we can prevent, instead of minor ones we can only grieve over? When will politicians start thinking about, talking about, doing something about, leading toward the really important issues of the coming century? When will citizens insist that they do?