In 1988, it was the spectre of Yellowstone National Park on fire. In 2003, it was the horror of thousands dying from heat in prosperous western Europe. The planet’s standout heat wave in 2010 plagued much of European Russia, including Moscow.

The difference between El Niño and La Niña can be a huge one for U.S. weather and for global climate. A strong El Niño can nudge global temperatures upward for up to a year.

A study that includes NCAR scientists suggests that plant leaves emit far less methane when exposed to sunlight than previously thought. The research estimates that foliage is the source of less than 1% of Earth’s methane emissions.

There’s only so much air to go around. Since we inhale trillions of molecules with every breath, a few of them may have been exhaled by people who lived hundreds or thousands of years ago.

The Asian monsoon is providing a pathway for pollutants to rise high in the atmosphere.