Few people can explain why Boston has 70-degree weather in December and snow in April.

But with his recent award of a "genius grant," Loeb Associate Professor of the Natural Sciences Daniel P. Schrag has proven he is an expert in the climate research field.

A recipient of this year's MacArthur Fellowship, Schrag, along with 24 other young stars in their respective fields, will be awarded a $500,000 grant, plus health benefits, over a period of five years--no strings attached.

"It was a complete surprise," Schrag said. "It was particularly nice because a colleague called me. He's on the board of the MacArthur Foundation."

"When he left a message saying it was urgent I assumed it was about taking care of his dog or his house," he added.

The Foundation does not hold a nomination or application process, and the winners are only notified after the final decision is made.

Though it was a surprise to Schrag, the award did not shock his colleagues.

"Dan Schrag is exactly the kind of person the foundation had in mind," said James G. Anderson, Weld professor of atmospheric chemistry and chair of the department of chemistry and chemical biology.

"He is spectacularly brilliant," Anderson added. "He integrates many fields together."

Schrag received a Ph.D. in geochemistry from the University of California at Berkeley seven years ago. After spending three years at Princeton, he joined Harvard's Earth and Planetary Sciences department in 1997.

Schrag's work focuses on the history of climate, from studies of drastic changes millions of years ago to global warming and its effects today.

An El Nio expert, Schrag tracks its ongoing changes and also reconstructs the pattern of El Nios in the last 125,000 years.

Schrag and his colleagues have also studied conditions during the last Ice Age 20,000 years ago, hoping to discover the ocean's temperature during the period.

And, in his spare time, Schrag is also working on a theory that the earth was nearly encased in ice for a period 700 million years ago.

Schrag said while the money and the award are wonderful, the recognition that his field of study is receiving is even more important.

"The question of how humans are affecting Earth's climate are going to become more and more important," he said. "This a huge challenge for everyone."

Although Schrag has not yet decided how to spend the money, he said increasing awareness of global issues is one of his main priorities.

"I want to spend it on something that will support the work I'm doing, but in a way that is somewhat unconventional--something I couldn't do with research money from the government or from Harvard," he said.

Other recipients this year include a choreographer, a radio producer and a cartoonist.

Last year, Professor of Physics Juan M. Maldacena was a recipient.