A pool of warm water lurking beneath the surface of the western Pacific has been slowly sloshing eastward in the past few months. This traveling wave of warm water is one of the signs that climate conditions are favorable for the emergence of El Niño later this year.
In October 2003, a little-known think tank in the Department of Defense quietly released a report warning that climate change could happen so suddenly it could pose a major threat to our country's national security. Why was the Pentagon worried about abrupt climate change? Because new evidence from Greenland showed it had happened before.
Among the questions triggered by the entrapment of a Russian ship near Antarctica on Christmas Eve were whether the ice conditions were out of the ordinary, and, if so, whether long-term climate change was playing a role.
From reindeer to regional temperature patterns, from sea ice age to Greenland surface melt, the Arctic Report Card is a yearly assessment of the Arctic's physical and biological systems and how they are changing. This collection of visual highlights from the 2013 report is a story of the Arctic in pictures.
The most likely explanation for the lack of significant warming at the Earth’s surface in the past decade or so is that natural climate cycles caused shifts in ocean circulation patterns that moved some excess heat into the deep ocean.
While heat is stored and mixed throughout the depth of the ocean, it is the temperature at the surface—where the ocean is in direct contact with the atmosphere—that plays a significant role in weather and short-term climate.
Maps of the thousands of storms that have passed through the Eastern Hemisphere tropical oceans in the past century or so reveal a more crowded landscape than similar maps of the Western Hemisphere. Unlike the Western Hemisphere, where storms are mostly confined to areas north of the equator, the Eastern Hemisphere sees storms in both north and south tropical waters.