Ice core reveals longest-ever continuous record of Earth’s climate

A 2.8-kilometre-deep ice core has yielded the longest continuous record of Earth’s climate and atmospheric conditions, stretching back 1.2 million years. Data from the core show how the concentration of carbon dioxide in the atmosphere tracked changes in global temperatures across multiple cycles of climate change. The core covers a period in Earth’s history during which ice ages became less frequent but more brutal. Researchers are hoping the oxygen isotopes and carbon dioxide in the core can provide some hints as to what caused the switch.

Ancient meteorite was ‘giant fertiliser bomb’ for life

A meteorite up to 200 times bigger than the one that killed the dinosaurs might have acted as a “giant fertiliser bomb” that helped early microorganisms to thrive more than 3 billion years ago. The space rock would have caused a tsunami, partially evaporated the oceans and plunged Earth into darkness. On the plus side for Palæoarchæan life, it also released phosphorus and sloshed iron-rich water up from the deep.

Did complex life start on Snowball Earth?

More than 500 million years ago, the globe was covered in glaciers and sea ice. This Snowball Earth seems hostile to life, yet it was probably during this time that single-celled organisms first evolved into complex, multicellular creatures. One possible answer to this conundrum: when seawater gets colder, it gets more viscous, so individual cells could have started to stick together to move through it more efficiently in search of food. In experiments with modern single-celled green algae, cells living in viscous gels formed coordinated groups to keep swimming.

Tree rings reveal drought that might have doomed the Hittites

Three years of severe drought could have contributed to the mysterious collapse of the ancient Anatolian empire of the Hittites 3,000 years ago. Tree rings from ancient juniper timber revealed that there was little rainfall in the area from 1198 to 1196 BC, which could have forced the Hittites to abandon their capital, perhaps dooming the civilisation. Some researchers agree with this assessment, but others think it misses the fact that 1190 BC was the beginning of a 200-year mega-drought that extended from Spain to India.

Did a mega drought topple empires 4,200 years ago?

In Mesopotamia in about 2200 BC, a mega drought lasted for decades or possibly even centuries. The drought might have contributed to the collapse of the Akkadian Empire, in what is now Syria and Iraq. But the drought’s extent is a matter of debate. Palæoclimatologists are working to pin down more details, which could hold clues to the kinds of natural droughts the world might face that could greatly exacerbate the impacts of climate change.