Students, faculty and Ames citizens came away from a lecture given by an ISU professor with a greater knowledge of global warming on Earth.

Gene Takle, professor of agronomy and geological and atmospheric sciences, spoke Wednesday night in the Alliant Energy-Lee Liu Auditorium at Howe Hall about the ever-changing climate of the planet and how greenhouse gases will affect people in the future.

“Our planet is unique in the universe in that it is the only place with all three phases of water on it. We wouldn’t have life without it,” Takle said.

Takle said humans are making too much of an impact on the atmosphere for nature to fully counteract the effects.

“We currently produce enough carbon dioxide that, distributed [equally] among everyone on earth, each individual is responsible for 30 tons a year,” he said.

He also stressed that atmospheric carbon dioxide lasts longer than the general population might think.

“The half-life of carbon dioxide is 100 years. That means that, for just my 30 tons, there will still be 10 to 15 tons 100 years from now, and 3 tons 100 years from that,” he said.

Takle then showed several climate models, which illustrated the fact that there has been a large increase in the average global temperature over the last 30 years.

“We don’t have the bitter winters of 30 years ago,” Takle said.

He explained that the earth interacts with the universe via radiation, and the energy the planet receives from the sun is expelled as thermal radiation. He said ideally, the amount of energy that goes into the planet equals the amount coming out, but the earth is retaining more energy than it expels.

“Right now there is a 0.7-watts-per-square-meter difference between energy in and energy out,” Takle said. “For reference, a difference of one watt [per square meter] is enough of an imbalance to irreversibly destroy the Greenland ice sheet.”

Disappearing Arctic ice was another issue Takle addressed. His climate models projected that the ice would be completely gone by the last half of the century, which would be disastrous for seaboard cities.

“Continental glaciers melting could lead to up to a 1-meter rise in sea level. A rise like that puts a good portion of southern Florida, including Miami and the Kennedy Space Center, underwater,” he said.

Takle finished by saying that most policies under discussion to combat these trends will only start taking effect in the latter half of the century. He divided the future into two phases: adaptation, where humanity concerns itself with adapting to the changes in temperature, and political reaction, where results to policy changes can start to be seen.

Takle left the crowd with a heated prediction about the future.

“The projected temperature levels that all of these plans propose to bring us almost overlap until the year 2050, and no model in existence shows a cooling in the future,” he said.

Some of those in attendance came away with a renewed sense of the seriousness of climate change.

“We need to be concerned citizens about this in the future,” said Jenna Rinehart, senior in anthropology. “He put it in more understandable terms than are usually used on this topic.”