Jeremy Rifkin does not paint a bright picture of our civilization's future.

The author, philosopher and activist, lecturing to a crowded Schwab Auditorium last night, pointed to environmental crises he believes are a threat to our species and urged his audience to take action before it's too late.

The issue foremost in his mind during the presentation was the greenhouse effect, the gradual rise in the earth's temperature resulting from increased atmospheric carbon dioxide, which traps heat on the earth's surface.

"The greenhouse world is the greatest environmental threat in history," Rifkin said. "We are burning up on this planet, and we can't get off." It may not happen next year, but will happen, he said.

Rifkin described a chilling scenario in which the entire island of Manhattan was underwater, Phoenix averaged 112 degrees a day, the entire groundwater supply was contaminated by seawater, and forest fires and drought were rampant.

"Welcome to the Greenhouse World," he said.

The increase in temperature this could cause -- as much as nine degrees in the next 40 years -- would be the sharpest rise since the Ice Age, Rifkin said. All the organisms on the planet that have adapted to their narrow temperature span could not withstand the shift and would perish, he said.

Rifkin said the phenomenon is not an accident or part of a cycle -- it is a direct result of human industry's spewing of gases like chlorofluorocarbons and methane into the atmosphere, and now we must face the consequences.

"There's no such thing as a free lunch. You have to pay the piper . . . we have literally affected the chemistry of an entire planet," he said.

He also expressed concern over the depletion of the earth's ozone layer, a protective buffer from the sun's harmful rays. Again, Rifkin placed the blame on careless industries and denial that the problem is there.

"When that ozone layer tears open, we are bombarded by ultraviolet rays because we have no protection . . . we're paying for the industrial age. (People) will look back on this and say,'This was the age of progress?' "

Rifkin took his argument one step further to attack the entire foundation of scientific knowledge.

Scientists, he said, have been taught to gain knowledge by isolating the environment, controlling it and observing it. Instead, Rifkin argued, knowledge should be attained by surrendering ourselves to our environment and participating with it.

Rifkin also contended society should opt for long-term "sustainability" rather than short-term efficiency. He said he prefers elegant Italian cathedrals that take a century to construct to prefabricated office buildings that will last 30 years.

"(The environment) is very bad; I've taken a number of courses on the subject and what he paints is a pretty realistic picture," said Gary Quay (senior-English).

Rifkin did not lose his sense of humor amidst all the dispute he caused. He playfully scorned an audience member for handing him a plastic cup full of tap water, and earlier pointed to his balding head and said with a smile, "acid rain."