Earth

Animals

Dry pet food may be more environmentally friendly than wet food

The environmental cost of wet pet food is higher than dry food, scientists say. That may be because wet food gets most of its calories from animals.

Animals

These devices use an electric field to scare sharks from fishing hooks

SharkGuard gadgets work by harnessing sharks’ ability to detect electric fields. That could save the animals’ lives, a study suggests.

Health & Medicine

Pollution mucks up the lungs’ immune defenses over time

A study of immune tissue in the lungs reports that particulate matter buildup from air pollution may impair respiratory immunity in older adults.

Ecosystems

Tiger sharks helped discover the world’s largest seagrass prairie

Instrument-equipped sharks went where divers couldn’t to survey the Bahama Banks seagrass ecosystem.

Humans

The world population has now reached 8 billion

In a first, the global population surpassed this milestone on November 15, according to a projection from the United Nations.

Oceans

Sharks face rising odds of extinction even as other big fish populations recover

Over the last 70 years, large ocean fishes like tuna and marlin have been recovering from overfishing. But sharks continue to decline toward extinction.

Climate

Greenland’s frozen hinterlands are bleeding worse than we thought

An inland swath of the Northeast Greenland Ice Stream is accelerating and thinning. It could contribute much more to sea level rise than estimated.

Earth

Catastrophic solar storms may not explain shadows of radiation in trees

Tree rings record six known Miyake events — spikes in global radiation levels in the past. The sun, as long presumed, might not be the sole culprit.

Climate

Wind turbines could help capture carbon dioxide while providing power

Turbulent wakes from wind turbines can concentrate CO₂ from cities and factories, making it easier to remove the greenhouse gas from the atmosphere.

Earth

Particles from space provide a new look inside cyclones

Cosmic rays that smash into the atmosphere make muons that are sensitive to changing air pressure inside storms.

Climate

Here’s what happened to the Delaware-sized iceberg that broke off Antarctica

The powerful pull of currents in the Southern Ocean probably pulled apart the largest remnant of a massive iceberg that split off Antarctica in 2017.

Earth

Landslides shaped a hidden landscape within Yellowstone

Scientists have used lasers to get a detailed view of the national park’s topography, and they’ve spotted more than a thousand landslides.