If ignorance is bliss, do we associate doomsaying with intelligence? Is that why our nation's academics so enjoy predicting decline? Or maybe they believe the general public won't listen to them unless they're forecasting the end of the world. It's sort of the approach of preachers like Harold Camping, the Christian radio broadcaster who predicted the apocalypse would take place last May. Indeed, the advice to doomsaying academics and apocalyptic religious leaders could be very similar. It's fine to predict the end of the world. Just don't say it's going to happen next Tuesday. Because once next Tuesday comes, you're going to look pretty silly. Now another group of twenty-two academics (an interdisciplinary committee of scientists, no less) has failed to take that advice. They've written a report (just published in Nature) that, in the words of the Chronicle of Higher Education concludes "the earth appears headed toward catastrophic and irreversible environmental changes." According to the Chronicle: "The report's conclusions center on a measure of the amount of the earth's land surface that has been transformed by people, from forests and prairies to uses such as cornfields and parking lots. The percentage of transformed land now stands at 43 percent, with the world's population at seven billion." "The scientists contributing to the report have calculated the various forms of damage that will be seen when the usage level exceeds 50 percent, as is expected around 2025, when the population reaches eight billion," Anthony Barnosky, the lead author of the report and a professor of integrative biology at UC Berkeley, told the Chronicle. The authors of the report announce that, of course, a global response is needed and that it will require a lot of cooperation among countries. Of course, they are also very skeptical that our polarized nation will be able to deal with such problems. Barnosky told the Chronicle: "I don't know how much it will sway the people who are just not inclined to believe any of this stuff anyway, who just basically will put their heads in the sand and say, Let's go on with business as usual." Of course, one wonders what the authors might have us do, since they also make clear that make clear that "they cannot be totally sure when the earth's environment will reach a 'tipping point' beyond which recovery to anything resembling current conditions will be impossible, or even if that will happen." Wait! They're not sure? I thought this was science! If they're not really sure, maybe we should bury our heads in the sand. Particularly if the alternative is turning our economy upside down to limit carbon emissions, putting caps on how much developing countries can develop and engaging in draconian population control measures. But then there is this comforting bit of reporting. The Chronicle interviews none other than Paul Ehrlich, who also has a companion piece in Nature. For those who need a refresher, Ehrlich's 1968 book, The Population Bomb, began: "The battle to feed all humanity is over. In the 1970s, the world will undergo famines -- hundreds of millions of people are going to starve to death in spite of any crash programs embarked upon now." He predicted mass starvation in India, among other places, a country that has experienced an economic boom in the past few decades despite having doubled its population. Ehrlich later lost a bet he placed with economist Julian Simon in 1980. The two picked five commodities -- copper, chromium, nickel, tin, and tungsten -- and Simon predicted their prices would go down in ten years, while Ehrlich, who believed that population growth would lead to shortages of everything, predicted the prices would go up. Simon won and Ehrlich paid. Ehrlich also predicted that the countries that were best able to control their populations -- he advocated offering incentives for sterilization and luxury taxes on families that had more than one child -- would be the most successful ones going forward. Of course, a quick look, for example, at stagnant birth rates across the economically moribund countries of Europe now might suggest otherwise. But Ehrlich refuses to be deterred by facts. Of the new report, he tells the Chronicle, "I suspect it's a little too optimistic. . . ." He complains, "Generally the scientific community has spoken many times, but nobody's paying any attention." Well they're not paying attention to Harold Camping either.