The Speculist

Planetary Accommodation?

Item 6 of yesterday's " Better All The Time #2" touched on one way the earth can cope with the Greenhouse Effect - increased heat leads to increased evaporation which leads to increased rain which leads to increased vegetation. And vegetation absorbs greenhouse gases.

Today, the New York Times reported on another way the earth can cope with increased emissions – by directly blocking sunlight.

…hundreds of instruments around the world recorded a drop in sunshine reaching the surface of Earth, as much as 10 percent from the late 1950's to the early 90's, or 2 percent to 3 percent a decade…

Dr. James E. Hansen, director of the NASA Goddard Institute for Space Studies in Manhattan, said that scientists had long known that pollution particles reflected some sunlight, but that they were now realizing the magnitude of the effect…

Satellite measurements show that the sun remains as bright as ever, but that less and less sunlight has been making it through the atmosphere to the ground.

Pollution dims sunlight in two ways, scientists theorize. Some light bounces off soot particles in the air and goes back into outer space. The pollution also causes more water droplets to condense out of air, leading to thicker, darker clouds, which also block more light.

Via KurzweilAI

Of course increased evaporation also leads to thicker darker clouds.

Global Warming is a complicated issue. We simply don't know enough about the effect of emissions, our planet's ability to cope, or even how technology will allow us to clean up the environment in the near future.

We do know that the world's population requires modern technology to survive. And I suspect that increased technology will allow us to decrease emissions. In the meantime we should tread lightly.

Posted by Stephen Gordon at May 13, 2004 02:57 PM | TrackBack