Changing Climates Key Words

• Ice age:

  A period of time when Earth has permanent ice sheets
• Quaternary period:

  The time period in the earth’s history that began about 2.6 million years ago and continues today: includes the Pleistocene epoch and the Holocene epoch
• Pleistocene epoch:

  First part of the Quaternary period – lasted from 2.6 million years ago to 11,700 years ago
• Holocene epoch:

  Second and current part of the Quaternary period – started 11,700 years ago
• Glacial periods:

  Colder periods that normally last about 100,000 years
• Interglacial periods:

  Warmer periods which normally last about 10,000 years
• Ice cores:

  Tubes of ice drilled out from the depth of an ice sheet
• Isotopes:

  Isotopes are atoms that have the same atomic number, but a different mass number, which is the number of protons and neutrons. The dominant oxygen isotope is 16o , meaning it has 8 protons and 8 neutrons, but 18o , an isotope with 10 neutrons, also exists. Lots of 16o in ice cores and Earth was colder, lots of 18o and Earth was warmer.
• Carbon dioxide:

  A colourless, odourless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in air (about 0.03 per cent) and is absorbed by plants in photosynthesis. Lots of CO2 bubbles in ice cores suggests warmer temperatures and vice versa
• Sea ice maximum/ minimum:

  The maximum/minimum area of the Arctic Ocean covered in ice in any year
• Global warming:

  An increase in the average temperature of the Earth’s atmosphere and oceans
• Eccentricity:

  Changes in the shape of the earth’s orbit
• Obliquity:

  Changes in how earth tilts on its axis
• Precession:

  The amount Earth wobbles on it’s axis
• Sun spots:

  A temporary dark spot on the Sun’s surface caused by magnetic storms
• Natural greenhouse effect:

  The natural process by which Earth is kept warm by gases that trap the Sun’s energy in the atmosphere
• Greenhouse gases:

  Gases in the atmosphere, such as CO2, that acts like the glass roof on a greenhouse, increasing temperature
• Sun’s radiation:

  The energy from the Sun
• Enhanced greenhouse effect:

  The trapping of more of the Sun’s energy because of the cumulative effect of greenhouse gases, causing Earth’s temperature to increase
• Global warming potential:

  When the same quantities of different gases trap and absorb different amounts of radiation
• Deforestation:

  Removal of trees
• Carbon footprint:

  The amount of carbon emissions produced by individuals, organisations or communities
• Climate change refugees:

  People who are forced to leave their homes and communities because of the impacts of climate change
• Thermal expansion:

  As the temperature of water in the oceans increases, the water expands making sea levels rise

   
• Melting glaciers:

  As glaciers melt, water that was stored as ice is added to the world’s oceans
• Melting ice caps:

  As the large expanses of ice in the Arctic and Antarctic melt, more water is added to the oceans
• Yield:

  The amount of food grown per hectare
• Species refugees:

  When species of animals move to different parts of the world e.g. butterflies moving north
• Flash flooding:

  Flooding that appears very quickly as a result of heavy rain