Natural Climate Patterns

Natural variability can explain much of Earth's average temperature variation since the end of the last ice age, but over the past century, global average temperature has risen from near the coldest to the warmest levels in the past 11,300 years.

Wednesday, January 1, 2014

  • A few days of unusually cold weather in the U.S. and Canada aren't a sign that a century-or-more trend of rising global surface temperatures has reversed itself. In fact, the cold wasn't even all that widespread for the Northern Hemisphere.

  • Meteorologists have known for years that the pattern of the polar vortex determines how much cold air escapes from the Arctic and makes its way to the U.S. during the winter. Climate scientists are wondering if a warmer Arctic could explain its odd behavior in recent years.