Monica+and+Keheili

Past to the Future: Then and Now Climate Change

It’s 15,000 BCE and you're standing on Liberty Island, New York. Scanning seaward, you see ice blocks the size of skyscrapers. It's a spring day (I NEED A SENSE OF THE TIME OF YEAR SO I CAN SENSE THE ODDNESS, FROM OUR CURRENT PERSPECTIVE), but a chilly 32 degrees. In 50 years, the entire landscape will be transformed, those chilly skyscrapers just a memory.

While New York is besieged by ice, the Bahamas are parched from months without rain. The air is saturated with dust. Here you struggle to breathe.

Within 50 years, the ice will melt in New York. The Bahamas will ooze -- think Brazilian rainforest.

The annual temperature will have risen only 7 ° F, but with catastrophic consequences are catastrophic.

Researchers at the University of Miami study these past rapid climate change events, known as Heinrich events. They may be the key to future climate change. But the climate history of the Bahamas is stored in an odd place: underwater caves.

To get to them, divers must learn to navigate in the infinite blackness of the caves. The dangerous work requires years of training to perform.

In the caves, they hunt for stalagmites, rocks that grow up from the bottom of the cave floor. The bring their harvest back to the laboratory. They are rock -- solid calcium carbonate rock -- with layers of black, brown and red. Those layers, like tree rings, provide clues to the age at which they were formed.

A 15-inch tall stalagmite may be sampled for chemical properties 2,000 times. Each sample is less than the amount of salt one would sprinkle on a meal.

These sprinkles reveal the exact timing of abrupt climate change events and characterize the changes. The changes they record may improve our understanding of how contemporary increases in carbon dioxide are driving climate change.

I THINK I'D SHORTEN THE OPENING AND INCREASE THE EXPLANATION OF WHAT THE STALAGMITES REVEAL AND HOW THEY REVEAL IT. THIS NEEDS A LITTLE MORE SCIENTIFIC CONTENT. AND I'D FOCUS FROM THE BEGINNING ON THE STALAGMITES BECAUSE THEIR USE RAISES ALL SORTS OF QUESTIONS.