Today marks the 38th annual celebration of Earth Day, and once again the event comes with its fair share of PR hype and misleading marketing campaigns. In the spirit of dedicating ourselves to genuine concern for the planet, today is therefore a good time to look carefully at corporate environmental claims, some of which consist more of empty rhetoric than real substance. Companies like Wal-Mart are announcing environmental initiatives. General Electric has its "Ecomagnation" advertising campaign. In Singapore, a shopping center is advertising that customers can "shop to save planet earth" -- and if they buy enough, they might win a new car! The ritual of green hypocrisy frequently requires that companies and politicians redefine environmental progress in increasingly creative ways. Last week, for example, George W. Bush announced a plan to address the problem of global warming by "halting the growth" of U.S. greenhouse gas emissions by the year 2025. Beyond the fact that this target date is 17 years in the future, what really means is that during those 17 years not only will greenhouse gas emissions continue, the amount of those emissions will continue to grow. As columnist Gail Collins observed in the New York Times, this would be akin to having an overweight person announce a plan to achieve "an 18 percent reduction in the rate at which he was gaining weight, to be reached within the next decade."