Columbia University

Pumping draws arsenic toward a big-city aquifer

Naturally occurring arsenic pollutes wells across the world, especially in south and southeast Asia, where an estimated 100 million people are exposed to levels that can cause heart, liver and kidney problems, ...

Sep 11, 2013
3.8 / 5 (4) 0

Tackling an Ice Age mystery

In the northern hemisphere, ice sheets ebb and flow in 100,000-year cycles, driven by varying amounts of sunlight falling on Earth's surface as its orbit and orientation toward the sun changes. But astronomical variations ...

Sep 05, 2013
4.8 / 5 (5) 0

Planning in the near term for climate change

When scientists talk about climate change, they usually mean significant changes in the measures of climate over several decades or longer. Climate variability generally refers to seasonal changes over a ...

Jun 27, 2013
2.5 / 5 (11) 0