Earth and Human Activity

Animals

As the tropics warm, some birds are shrinking

Migratory birds are getting smaller as temperatures climb, studies had showed. New evidence shows dozens of tropical, nonmigratory species are, too.

Animals

Can scientists develop an icy sanctuary for Arctic life?

The final refuge for summer sea ice may also protect the creatures that depend on it. Saving it is an ambitious goal with many hurdles.

Earth

From icebergs to smoke, forecasting where dangers will drift

Smoke drifts. Fish eggs float downstream. Where such drifting things end up may seem a mystery. But research can predict where they’ll end up.

Chemistry

A new way to make plastics could keep them from littering the seas

Borrowing from genetics, scientists are creating plastics that will degrade. They can even choose how quickly these materials break down.

Microbes

Genes point to how some bacteria can gobble up electricity

A new study shows how some microbes absorb and release electrons — a trait that may point to new fuels or ways to store energy.

Earth

Analyze This: Nutrients from sewage may harm coastal ecosystems

A new model suggests that 58 percent of coral reefs and 88 percent of seagrass beds are exposed to excess nitrogen from wastewater.

Ecosystems

Leaky sewer pipes pollute urban streams and bays with drugs

Scientists find that leaking sewer pipes around Baltimore, Md., spew thousands of doses of medicines into the Chesapeake Bay and other waterways.

Climate

Scientists Say: El Niño and La Niña

El Niño and La Niña are part of a climate cycle that results in major weather changes every few years.

Materials Science

Analyze This: Hardened wood can make sharp steak knives

Researchers treated wood to make it hard and dense. Out of it, they carved sharp knives and nails that could substitute for ones made of steel.

Chemistry

Scientists find a ‘greener’ way to make jeans blue

When coated onto jeans, a plant-based polymer reduces water and cuts the amount of toxic chemicals needed.

Chemistry

Everyday plastics can pollute, leaching thousands of chemicals

Plastic bags and containers leach potentially toxic chemicals into both food and water, but researchers yet don’t know how they might affect health.

Agriculture

Potty-trained cows could help reduce pollution

About a dozen calves have been trained to pee in a stall. Toilet training cows on a large scale could cut down on pollution, scientists say.