Climate Change

• Ice sheets


  • Made up of layers of ice - one layer formed each year
• Analysing ice cores


  1. Scientists drill into ice sheets to get long cores of ice

  2. Analyse gases trapped in the layers to determine past temperatures
• One ice core from Antarctica showed how temperature has changed over the last 400,000 years
• Temperature records


  Since 1850s, global temperatures have been measured accurately using thermometers
• Pollen analysis


  1. Pollen from plants gets preserved in sediment

  2. Scientists identify and date the preserved pollen to show which species were living at that time

  3. Preserved pollen from similar plants shows climate conditions were similar
• Tree rings


  • As a tree grows it forms a new ring each year - thicker in warm, wet conditions
  • Scientists take cores and count the rings to find the age of a tree
  • Tree rings are a reliable source of evidence of climate change for the past 10,000 years
• Climate change is any significant change in the Earth's climate over a long period
• Recently, the earth is seeing a rapid increase in global temperatures - this is called global warming and is a human induced climate change
• Natural causes of climate change

  • Changes in the Earth's orbit around the sun
  • Major volcanic eruptions ejecting ash into the atmosphere
  • Changes in the Sun's output of energy
• Human causes of climate change

  • Burning of fossil fuels
  • Farming of livestock producing methane
  • Deforestation
• Greenhouse effect


  • Greenhouse gases, such as CO2, absorb outgoing heat so less heat is lost and some is reflected back to earth
  • Too much greenhouse gas in the atmosphere means too much sun energy is trapped and the planet warms up
• The rate of recent rise in global temperatures is alarming
• There is scientific agreement that human activities are causing global warming through the greenhouse effect
• Environmental effects of climate change

  • Shrinking glaciers and ice sheets, leading to sea level rise
  • Shrinking sea ice, leading to loss of polar habitats
  • Coral reef dying due to rising sea temperatures
  • Changing precipitation patterns
  • Habitat destruction and biodiversity loss
• Effects of climate change on humans

  • Increased disease
  • Changing crop yields
  • Increased shipping and extraction in the Arctic
  • Droughts reducing food and water supply
  • Increased flood risk
  • Declining fish stocks
  • Increased extreme weather
  • Threats to skiing industry
• Mitigation strategies


  1. Carbon capture and storage

  2. Replacing fossil fuels with nuclear and renewable energy

  3. International agreements to cut greenhouse gas emissions

  4. Planting trees
• Adaptation strategies


  1. Changing agricultural practices to be more hardy and suitable for harsh conditions

  2. Using biotechnology to create new crop varieties

  3. Installing water meters and recycling water

  4. Building physical defences against sea level rise
• Weather in the UK is becoming more extreme
• Temperatures have become more extreme in recent years
• The coldest for over 100 years, with snow and ice causing several death and school and road closures

  December 2010
• It is raining more - more rainfall records have been broken since 2010 than in any other previous decade on record
• The wettest year

  2013
• The wettest month ever

  December 2015
• Major flooding occurs often
• Extreme weather

  Climate change can increase the frequency and intensity of extreme weather events
• Flooding is becoming more frequent in the UK

  As a warmer atmosphere can hold more moisture