History

In a remote cave in northeast India, rainwater has slowly dripped from the ceiling in the same spots for over 1,000 years. With each drop, minerals in the water accumulate on the floor below, slowly growing into calcium carbonate towers known as stalagmites. These stalagmites are more than geological wonders – like tree rings, their layers record the region’s rainfall history. They also carry a warning about the potential for catastrophic multiyear droughts in the future. By analyzing the geochemistry of these stalagmites in a new study published Sept. 19, 2022, in the Proceedings of the National Academy of Sciences, we were able to create the most precise chronology yet of the summer Indian monsoon over the past millennium. It documents how the Indian subcontinent frequently experienced long, severe droughts unlike any observed in the last 150 years of reliable monsoon rainfall measurements. The drought periods we detected are in striking synchrony with historic...

Long before colonialism brought slavery to the Caribbean, the native islanders saw hurricanes and storms as part of the normal cycle of life. The Taino of the Greater Antilles and the Kalinago, or Caribs, of the Lesser Antilles developed systems that enabled them to live with storms and limit their exposure to damage. On the larger islands, such as Jamaica and Cuba, the Taino practiced crop selection with storms in mind, preferring to plant root crops such as cassava or yucca with high resistance to damage from hurricane and storm winds, as Stuart Schwartz describes in his 2016 book “Sea of Storms.” The Kalinago avoided building their settlements along the coast to limit storm surges and wind damage. The Calusa of southwest Florida used trees as windbreaks against storm winds. In fact, it was the Kalinago and Taino who first taught the Europeans – primarily the British, Dutch, French and Spanish – about hurricanes and storms. Even the word ‘hurri...

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years. Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today. The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists – until now. In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado’s Pikes Peak....

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years. Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today. The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists – until now. In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado’s Pikes Peak....