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In 1878, the American geologist and explorer John Wesley Powell drew an invisible line in the dirt—a very long line. It was the 100th meridian west, the longitude he identified as the boundary between the humid eastern United States and the arid Western plains. Running south to north, the meridian cuts northward through the eastern states of Mexico, and on to Texas, Oklahoma, Kansas, Nebraska, the Dakotas, and the Canadian province of Manitoba on its way to the pole. Powell, best known for exploring the Grand Canyon and other parts of the West, was wary of large-scale settlement in that often harsh region, and tried convincing Congress to lay out water and land-management districts crossing state lines to deal with environmental constraints. Western political leaders hated the idea—they feared this might limit development, and their own power—and it never went anywhere. It was not the first time that politicians would ignore the advice of scientists.

A joint research project of the Chronology Laboratory of the Finnish Museum of Natural History and Natural Resources Institute Finland (Luke) suggests that the years 536 and 541–544 CE were very difficult for many people.

NASA satellite imagery showed that Tropical Cyclone Keni was being battered by vertical wind shear. NASA-NOAA's Suomi NPP satellite revealed that wind shear was pushing the clouds and storms associated with Keni to the southeast of the center.

Glaciers in the high mountain regions of the Himalayas offer a different picture to our Alpine glaciers: many of them are completely covered in debris, and many areas are overlooked by steep ice walls – vertical cliffs up to 30 metres high. From a distance, this makes the glacier surface look like the warty skin of a toad.

The Atlantic overturning – one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards – is weaker today than any time before in more than 1000 years. Sea surface temperature data analysis provides new evidence that this major ocean circulation has slowed down by roughly 15 percent since the middle of the 20th century, according to a study published in the highly renowned journal Nature by an international team of scientists. Human-made climate change is a prime suspect for these worrying observations.