The oldest ice core ever drilled outside the polar regions may contain ice that formed during the Stone Age — more than 600,000 years ago, long before modern humans appeared.
Scientists endured bitter winds to retrieve ancient ice from a blue ice field in the Allan Hills of Antarctica.
ice cores and records from the Black Death show lead entered the air from human activity – and scientists claim “natural background” levels are zero
A small team of researchers with Princeton University has found evidence that suggests that the amount of oxygen in the Earth’s atmosphere has dropped by 0.7 percent over the past 800,000 years.
