An ISU professor discussed climate change – a growing issue in the public dialogue – Monday night.

Gene Takle, interim director for agronomy and geological and atmospheric sciences, gave the climate lecture in the Campanile Room of the Memorial Union. The Osborn Research Club sponsored the lecture.

Takle, who has contributed to the Intergovernmental Panel on Climate Change, the organization that shared the Nobel Peace Prize with former Vice President Al Gore in 2007, talked about the causes of climate change, including the effects of the phenomenon.

Takle used charts in his PowerPoint presentation to illustrate how greenhouse gases – such as carbon dioxide and methane – and the Earth’s temperature have fluctuated and undergone cycles throughout history.

“This level of carbon dioxide has gone from about 180 parts per million up to about 300 over this 400,000-year period,” he said.

Takle also showed a series of images that illustrated the melting of the North Pole. It showed a dramatic reduction in ice in the North Pole from 2003 to 2006.

There was a rise in temperature in the middle part of the century. Takle said this can be attributed to the solar influence of the sun. However, the current rise cannot be attributed to this.

“The [temperature rise of the] last 25 years of the 20th century was unequivocally due to human contributions of greenhouse gasses,” he said.

Takle said some of the adverse effects of climate change will be felt most in the poorest countries of the world, which contribution the least to the problem as we see it today.

Takle addressed some of the skeptics’ arguments. One such argument was that the change in climate is due to the sun. However, Takle rebuked that argument.

“We’ve shown here that the sun is not the cause of the current rise.” he said.

Takle also talked about the common argument, that climates on the planet have changed before in the past.

“When you look at the rate of change, it’s unprecedented,” he said.

“We have not seen this kind of change in the last 400,000 years.”

Another argument Takle addressed was that there is no consensus on the existence of climate change.

“Weigh the document that’s coming around,” he said, referring to a book he was passing around, “Climate Change 2007 – The Physical Science Basis,” which was nearly 1,000 pages long.

The book was the IPCC’s fourth assessment report.

Takle also talked about the future and what needs to be done about climate change. He talked about the ISU Climate Initiative, which Takle said has had tremendous response on campus by people wanting to be involved.

“There’s wide interest in climate change on this campus, so it’s a challenge to us to try to organize and mobilize this intellectual talent focusing on issues that we think are important to the Midwest and U.S.,” Takle said.