Millennial-scale oscillations A) typically begin with a slow ...

[Mr. Wonderful]

Millennial-scale oscillations
 
  A) typically begin with a slow increase in temperature.
  B) take 500 or so years for a complete cycle.
  C) indicate the earth flips back and forth between warmer states and colder states.
  D) have little impact on precipitation patterns.

Question 2

Trace the major changes in temperature during the Holocene, with a special emphasis on the last 1,000 or so years. Also discuss evidence for the temperature changes.
 
  What will be an ideal response?

[tkempin]

Answer to Question 1

Answer: C

Answer to Question 2

Answer: Warming began about 15,000 years ago (prior to the start of the Holocene), only to be interrupted about 2,000 years later when colder conditions returned. Called the Younger Dryas, this colder period lasted for about 1200 years. Following the Younger Dryas, starting about 11,800 years ago, came another period of abrupt warming, with temperatures in Greenland increasing by about 1C per decade, bringing climate into the interglacial we enjoy today. The Holocene has not been uniformly warm, as reflected in the so-called Little Ice Age. Spanning perhaps 1400 to 1850, this was a cold period for western Europe. During these years, alpine glaciers advanced as temperatures fell by about 0.5C to 1C (0.9F to 1.8F). Historical records indicate that this seemingly small decrease in mean temperature had a considerable effect on living conditions throughout Europe. Shortened growing seasons led to reductions in agricultural productivity, especially in northern Europe, though its impact was felt in mountain records from around the world. Although in no sense is it a true ice age, it does represent the largest temperature change during historical times and is considered a global event.