Zeroes are important. A million seconds ago was last week. A billion seconds ago, Richard Nixon resigned the presidency. A trillion seconds ago was 30,000 BC, and early humans were using stone tools.

With time environmental issues got much more complicated. It is pretty easy, if you know what you are doing, to stop a company from pouring poison into a lake where kids swim. It is much harder to address all the myriad greenhouse gases emitted by different sources - from petrochemical refineries to hundreds of millions of peasants cutting down trees for their incredibly inefficient cook stoves.

Asbestos, EMFs, and CFCs have given us a degree of humility. When yesterday's "triumph of modern chemistry" turns out instead to be today's deadly threat to the global environment, it is legitimate to ask what else we don't know.

Environmentally, business in America in 1970 was very similar to business in China today. Even if a CEO wanted to be a responsible corporate citizen, he (and they were all "he's" then) simply couldn't invest a billion dollars in pollution controls to produce a product that was indistinguishable from those of his competitors. His products would be priced out of the market. Passing laws that created a clean, level playing field for whole industries had to be a core focus of the 1970s.

The more subtle thing is more speculative. The world is well past its long-term carrying capacity for human beings living a European, much less an American, lifestyle predicated on planned obsolescence. International economic growth is largely a matter of accelerated movement of materials from mines and forests to the dump. Instead of saving and buying decent furniture we can pass on to our children, we charge our credit cards for shaped heaps of sawdust and glue that fall apart in less than three or four years.

By 1975 - and continuing to today - all Americans came to believe that they had a "right" to a safe, clean, healthy environment. When I grew up, no one seriously criticized the steel mills and paper mills for the deadly stench they produced - that was the smell of prosperity. In the modern society, no one would tolerate such conditions in an American city.

There are a few obvious consequences and perhaps one subtle possibility. One obvious thing is that, to stimulate the economy, President Obama has committed to creating millions of green jobs that will leave a legacy - much as Roosevelt's public works did during the new deal.