Feel like you’re just not depressed enough today? Read the last bit of this Dot Earth post:

During a break, I asked [Nobel prize-winning atmospheric chemist Dr. F. Sherwood] Rowland two quick questions. The first: Given the nature of the climate and energy challenges, what is his best guess for the peak concentration of carbon dioxide? …

His answer? “1,000 parts per million,” he said.

My second question was, what will that look like?

“I have no idea,” Dr. Rowland said. He was not smiling.

What will a planet with 1,000 ppm of CO2 in its atmosphere look like? Worldchanging runs an excerpt from Peter Ward’s Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future, wherein he describes just such a world, which actually existed toward end of the Triassic period:

Waves slowly lap on the quiet shore, slow-motion waves with the consistency of gelatin. Most of the shoreline is encrusted with rotting organic matter, silk-like swathes of bacterial slick now putrefying under the blazing sun … [W]e look out on the surface of the great sea itself, and as far as the eye can see there is a mirrored flatness, an ocean without whitecaps. Yet that is not the biggest surprise. From shore to the horizon, there is but an unending purple color — a vast, flat, oily purple. No fish break its surface, no birds or any other kind of flying creatures dip down looking for food. The purple color comes from vast concentrations of floating bacteria, for the oceans of Earth have all become covered with a hundred-foot thick veneer of purple and green bacterial soup. …There is one final surprise. We look upward, to the sky. … We are under a pale green sky, and it has the smell of death and poison. We have gone to Nevada of 200 million years ago only to arrive under the transparent atmospheric glass of a greenhouse extinction event, and it is poison, heat and mass death that are found in this greenhouse.

In other words: 1,000 ppm will look like the end of industrial civilization and possibly the human race.

But hey, let’s stay focused on the real problem: high gas prices!