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Professor Matt Lachniet spends hours looking for clues. This Thursday, he shows us samples in his laboratory of stalagmites from Nevada caves. Some are thousands of years old, pointing to a time when this desert was actually hotter and drier, which coincides with a time when the oceans we now call the Pacific and the Arctic were warmer.

The latest national climate assessment captures the future impacts of a warming planet more completely than reports that have come before it, UNLV geology professor Matt Lachniet says.

We’ve entered some profoundly unfamiliar planetary territory.

We’ve entered some profoundly unfamiliar planetary territory.

Speculation aside, there are valuable facts presented by the study, one of which is that we still have time to establish climate change policies to thwart catastrophic events, says UNLV geoscience professor and climate change expert Matthew Lachniet.

How could a civilization as advanced as that of the Mayas collapse in the space of a few hundred years? The key to this mystery that has been brewing historians for centuries may lie at the bottom of an ancestral lake in Mexico City, Science magazine reveals on Thursday, August 2 .

As one of the most advanced civilizations of its time, the Mayans left behind puzzles related to their extinction.

The sediment under a lake in Mexico contains some of the long-sought answers to the mystery of the Mayan demise.