The issue focused on "beyond the obvious and long-term effects of global warming on human health and well-being in the United States and around the world."

The statement from the National Academies of Sciences in the United States and in other countries was based on the University of California, Santa Cruz's study of more than 8,000 school children in some 15 states.

The study was published in the journal Science.

The study did not control for how well the children were doing in