A University of Alaska Fairbanks professor emeritus known for his belief that carbon dioxide is not the sole cause of climate change presented his latest research Thursday.

More than 40 researchers and students gathered into a room at the International Arctic Research Center, now named after Syun-Ichi Akasofu, for the hour-long presentation.

"Retirement is good because I can spend the time to correct information," Akasofu said.

For several years now, Akasofu has put forward the idea that while the world was warming for most of the 20th century, it stopped warming sometime around 2000 or 2001. He clarified Thursday that according to his latest research, the oceans have stopped warming since that time, but it appears as if temperatures are still rising if one only looks at land temperatures.

Akasofu also was skeptical of reported changes in land temperature, however. For example, he noted that while many scientists claim global temperatures have risen slightly less than one degree on average across the past few decades, their studies don't take urbanization into account.

Tokyo, he said, appears to have warmed four degrees, but that does not take into account the fact that the number of dark manmade structures that absorb heat, raising temperatures in their vicinity.

The retired geophysics professor also questioned the accuracy of readings from weather stations where no one is there to regularly monitor the equipment.

"A friend of mine found one station where the temperature gauge was just outside the air conditioner," he said.

Still, Akasofu doesn't completely deny the existence of climate change, so much as question what causes it. One culprit he suggested is the recent lack of sunspots.

"Something is happening on the sun," he said. "There are no sunspots when there should be 50-100 right now, so people warn the sun has become warmer."

A similar phenomenon was observed between 1650 and 1700, which coincides with what researchers call the Little Ice Age, a period of widespread cooling that came shortly after a warming trend may have peaked sometime around 1000 AD.

However, Akasofu didn't necessarily connect that warming period to what the planet is experiencing now.

"Some people say it was a degree higher or about the same, but there were no thermometers, so how accurate were they?" he said.