Wonderful video showing noctilucent - or night-shining - clouds recorded on July 1 and 4. These clouds shine in the darkness, typically on summer nights.

Would climate change stop? The simple answer is no. A climate scientist explains.

The 5.8-magnitude earthquake in western Montana took place just after midnight, local time. It woke people up near the epicenter and was felt throughout the region. Expect aftershocks.

Across the US Southwest - amid a record-breaking heat wave - fires that started in early June continue to burn.

Good news for coral reefs at last! After 3 years, the global coral bleaching event is likely over, scientists say.

Ongoing drought - and increasing temperatures - have reduced water flow in the Colorado River, with more dramatic reductions expected. This ongoing, unprecedented event threatens water supplies in cities in the U.S. West and some of the most productive agricultural lands anywhere in the world.

The ice sheets are melting from both above and below, say scientists.

Cottonwood trees in the American West are a nuisance to some and a treasure to others. They yield shade, beautiful foliage and, in June, a kind of warm, fluffy "snow."

More tornadoes occur in the U.S. than any other country, mainly in the Great Plains, Midwest and southern states. Two meteorology professors answer questions.

Rock is apparently no match for Anthophora pueblo bees. Scientists have found their sandstone nests scattered across dry lands in the U.S. Southwest.