The exercise, being staged by a coalition of seven think tanks and other non-profits called the Climate Change Consortium, will get technical assistance from the U.S. National Laboratory at Oak Ridge, Tenn., a statement from the organizers said Tuesday.

It said the exercise would be held in Washington July 27-28 and would be the first of two. The second, slated for fall, will be focused on Africa.

"The security ramifications of climate change will affect both the developed and the developing world," said John Podesta, president of the Center for American Progress, a member group of the consortium. "This unique event will challenge participants to confront both the domestic and international security challenges of climate change."

Participants in the game, 40 of them, from the United States, Asia and Europe, will "provide a wide range of perspectives," said the statement, adding the scenario would be based on the recent report, "The Age of Consequences: the Foreign Policy and National Security Implications of Global Climate Change."

Led by the Center for a New American Security, the consortium includes the Center for American Progress, the Heinrich Boll Foundation, the Pew Center on Global Climate Change, the Rockefeller Brothers Fund, the Woods Hole Oceanographic Institution and Brookings Global Economy and Development.