# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Full Steam Ahead--Probably," by Ralph Lorenz. *Science,* 7 February 2003.

Researchers using computational mathematics are studying the Earth's climateand the behavior of the atmosphere. General circulation models and astatistical approach are used to determine whether Earth's climate is in an MEPstate ("a state in which the work output, the product of the heat flux and thetemperature gradient driving it, is largest"). The paper outlines work in thefield and some outstanding challenges and problems. "The MEP idea continues togenerate considerable friction among climate modelers---but perhaps that isexactly what we should expect."

*--- Annette Emerson*