Earth

Many useful metals unearthed from U.S. mines are discarded.

When mining operations dig for valuable metals, they often exhume ore containing other metals too. These by-product elements are usually treated as waste, but recovering even small fractions could offset the need to import them, researchers report August 21 in Science. For instance, recovering just 1 percent of rare earth elements from this material could replace imports.

“We’re used to skimming cream off the top,” says Elizabeth Holley, a mining geologist from the Colorado School of Mines in Golden. “We need to be better at recovering more from what we’re using.” More

By affecting cows’ diets, climate change can affect cheese’s nutritional value and sensory traits such as taste, color and texture. This is true at least for Cantal — a firm, unpasteurized cheese from the Auvergne region in central France, researchers report February 20 in the Journal of Dairy Science.

Cows in this region typically graze on local grass. But as climate change causes more severe droughts, some dairy producers are shifting to other feedstocks for their cows, such as corn, to adapt. “Farmers are looking for feed with better yields than grass or that are more resilient to droughts,” but they also want to know how dietary changes affect their products, says animal scientist Matthieu Bouchon.

For almost five months in 2021, Bouchon and colleagues at France’s National Research Institute for Agriculture, Food and Environment tested 40 dairy cows from two different breeds — simulating a drought and supplementing grass with other fodder, largely corn, in varying amounts.

The research team tested climate-adapted diets on cows, like the one seen here, at France’s National Research Institute for Agriculture, Food and Environment.INRAE/Matthieu Bouchon

The team sampled milk from all cows at regular intervals. Milk’s fatty acid and protein profiles impact cheese formation, melting qualities and nutrition, so the researchers chemically identified distributions of those molecules with a technique called gas chromatography. They also identified beneficial microbes in the milk by making Petri dish cultures.

They found that a corn-based diet did not affect milk yield and even led to an estimated reduction in the greenhouse gas methane coming from cows’ belching. But grass-fed cows’ cheese was richer and more savory than that from cows mostly or exclusively fed corn. Grass-based diets also yielded cheese with more heart-healthy omega-3 fatty acids and higher counts of probiotic lactic acid bacteria. The authors suggest that to maintain cheese quality, producers should include fresh vegetation in cows’ fodder when it is based on corn. More

Humankind will soon lose a great deal of vigilance over the ozone layer, which shields life on Earth from harmful solar radiation.

The impending loss of NASA’s Aura and the Canadian Space Agency’s SCISAT satellites threatens scientists’ ability to closely monitor compounds that destroy ozone and alter stratospheric circulation. With no planned missions to replace either satellite, a data desert in the stratosphere appears imminent, researchers warn in the March Bulletin of the American Meteorological Society. More

The Los Angeles wildfires were still burning when scientists started scouting the freshly charred burn scars to search for signs of another danger that’s yet to come — roaring torrents of rock and mud and water that can sweep downhill with deadly momentum.

Triggered by intense bouts of rainfall, these debris flows — as well as flash floods — become more likely to occur after an intense wildfire has scorched an area’s slopes and vegetation. While flash floods can be devastating, debris flows surge with even greater ferocity. At least half of their volume is sediment, and it’s mixed with burned trees, cars and boulders. More

Shifting is in a river’s nature. But when a river breaks free of its channel and carves a new path across the landscape, devastating floods may descend upon communities with little to no warning.

For decades, researchers have struggled to explain exactly how river channels become primed for such sudden diversions, or avulsions. A study published September 18 in Nature may have finally quelled the debate, showing how two factors work together to stage the rerouting of a river. Building on their findings, the researchers also developed a promising algorithm that can predict the new path of a river that has avulsed. More

Meteorologist Thea Sandmael watched the storm close in. It was near enough for her to spot a rotating dome of clouds emerging from its dark underbelly — the quickening of a tornado. By the time the spinning mass was 10 minutes away, Sandmael and her colleagues had shut down their radar instruments and evacuated their post.

“Just keep going,” she advised her colleague behind the wheel, who was rightly focused on maneuvering their SUV down the remote Alabama road. Following behind was another colleague in a truck carrying their cumbersome radar equipment. Evacuating was a good decision, she reflects: “We were sitting on the west side of the road, and the tornado touched down in our exact location.” More