Earth's orbit plays a big part.

• Position: Climate Change - Brief article

Climate scientists long have documented the strong control of Earth's orbital variations on the waxing and waning of the great ice ages, when huge "pluvial" lakes filled the valley floors of the Great Basin--a watershed encompassing five states, including most of Nevada. For years it was thought that Great Basin climate marched to the tune of a different drummer, and now scientists have revealed a 175,000-year-long climate record from the Great Basin, which shows ice age temperature oscillations centered around changes in Earth's orbit.

"Ice age temperature oscillations were the metronome and pacemaker of Great Basin climate change," says study coauthor Yemane Asmerom, professor in the Department of Earth and Planetary Sciences at the University of New Mexico, Albuquerque. "The research resolves a long-standing climate paradox arising from Devils Hole, Nev., which suggested incorrectly that climate was out of step with orbital variations."

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