Leading international economist Jeffrey D. Sachs ’76 will leave Harvard this summer to accept a teaching appointment at Columbia University, he said yesterday.

In his new post, he will direct Columbia’s Earth Institute, which focuses on economic development without environmental damage.

Columbia’s proximity to the United Nations will allow him to better coordinate his activities as special advisor to the U.N.’s Millennium Development Goals.

“It’s the combination of the U.N. and the fact that the Earth Institute has a significant scale of institutions, hundreds of researchers in sustainable development,” Sachs said. “Harvard has some of the world leaders, but not the scale of the activity.”

Sachs, who is currently Stone professor of international trade and serves as director of Harvard’s Center for International Development (CID), accepted Columbia’s offer yesterday afternoon.

He will assume his new positions as professor of sustainable development and director of the Earth Institute at Columbia starting July 1, Sachs said in a telephone interview late last night from Washington D.C.

Sachs serves as special advisor to U.N. Secretary-General Kofi Annan on the U.N.’s Millennium Development Goals, which seeks to halve worldwide poverty by 2015.

The ability to integrate his work for the U.N. with academic research were prime reasons for accepting the positions at Columbia, Sachs said.

“The U.N. is helping to lead many different processes to address the problems of global poverty, changes in the earth’s environment and risks to the ecosystem,” he said. “The Earth Institute is dealing with these on a daily basis.”

Sachs was careful to note that he will continue to be involved with Harvard in the future.

“Next year I’ll be dividing time between Harvard and Columbia,” Sachs said. “I will still have a position in many [of the] ongoing projects at the Center for International Development, but I will not be its director.”

Sachs also emphasized that his move does not reflect his dissatisfaction with Harvard.

“Since September 1972, I’ve been at Harvard, and the attachments are deep,” said Sachs, who also received his master’s and doctorate degrees at Harvard. “This move is not at all a reflection of any negative opinion.”

Sachs said that Columbia officials initiated talks about an offer shortly after he was appointed to the U.N. post on Feb. 1, and that negotiations have been ongoing for the last eight weeks.