When the first Earth Day took place in 1970, American environmentalists had good reason to feel guilty. The nation’s affluence and advanced technology seemed so obviously bad for the planet that they were featured in a famous equation developed by the ecologist Paul Ehrlich and the physicist John P. Holdren, who is now President Obama’s science adviser.

Their equation was I=PAT, which means that environmental impact is equal to population multiplied by affluence multiplied by technology. Protecting the planet seemed to require fewer people, less wealth and simpler technology  the same sort of social transformation and energy revolution that will be advocated at many Earth Day rallies on Wednesday.

But among researchers who analyze environmental data, a lot has changed since the 1970s. With the benefit of their hindsight and improved equations, I’ll make a couple of predictions:

1. There will be no green revolution in energy or anything else. No leader or law or treaty will radically change the energy sources for people and industries in the United States or other countries. No recession or depression will make a lasting change in consumers’ passions to use energy, make money and buy new technology  and that, believe it or not, is good news, because...

2. The richer everyone gets, the greener the planet will be in the long run.

I realize this second prediction seems hard to believe when you consider the carbon being dumped into the atmosphere today by Americans, and the projections for increasing emissions from India and China as they get richer.