A group of climatologists at Northern Arizona University are confirming that 2000 years ago, the Earth’s Arctic region had already entered a prolonged cooling phase. The phase continued up through the Middle Ages and on past the so-called Little Ice Age (1400 - 1800 C.E.). However, that all started to change (in the positive direction) between 1850 and 1900 C.E.–roughly in parallel with the onset and rise of the Industrial Revolution in the U.S. and Europe. And, by 1950, the warming trend had picked up in earnest.

Read More: http://ecoworldly.com/2009/10/29/2000-year-arctic-cooling-trend-reversed-itself-near-turn-of-20th-century/