A Belgian environment professor and an American historian have won this year's Blue Planet Prize, a Japanese environmental award sponsored by the nonprofit Asahi Glass Foundation.

Eric Lambin, 56, of Stanford University, has pointed out that changes in land use are causing global adverse effects on ecosystems and explained the relationship between economic activities and land use through socioeconomic data, which significantly influenced how public authorities and private enterprises develop land use policies.

Author of the trilogy, "Guns, Germs, and Steel," "Collapse" and "The World Until Yesterday," Jared Diamond, 81, provided insight into the roots of today's environmental issues. His work expanded on the significance of such issues in the history of human civilization.

The winners are scheduled to give lectures at The University of Tokyo on Dec. 12 and at Kyoto University on Dec. 14.

The Blue Planet Prize was established by the foundation in 1992 at the U.N. environmental summit in Rio de Janeiro. Two recipients are chosen annually for their contributions to solving global environmental problems.