Theme 2: Changing Environments 2.4 Climate Change – Cause & Effect The Quaternary period is the most recent period of geological time. It is a period that has been dominated by cold climates and ice shaping the land. Within the Quaternary period there have been periods known as: Glacials – when polar ice has reached much further south, covering large parts of the earth. Inter-glacials – when the polar ice retreated. At the start of the Quaternary, the continents were just about where they are today, slowing inching here and there as the forces of plate tectonics push and tug them about, but throughout the period, the planet has wobbled on its path around the sun. The slight shifts cause ice ages to come and go. By 800,000 years ago, a cyclical pattern had emerged: Glacial periods -Ice ages last about 100,000 years followed by warmer interglacial’s of 10,000 to 15,000 years each. The last ice age ended about 10,000 years ago. Sea levels rose rapidly, and the continents achieved their present-day outline.

The average world temperature is increasing The average world temperature is increasing! Between 1880 and 2004 it has increased from 13.9 to 14.6 Degrees Celsius The amount of carbon dioxide in the air has increased significantly over the last 200 or so years. The Arctic ice cap has shrunk by 40% over last 30 years! Sea levels are 18 mm higher than 100 years ago! Mountain glaciers are retreating.

Are there any POSITIVE consequences of climate change?