geography - climate change

• evidence for climate change - ice and sediment core

  ice cores are made of layers, if you drill down you cn analyse gases trapped.

  remains of organisms found in cores from ocean floor can be traced back 5 million years
• evidence for climate change - pollen analysis

  pollen is preserved in sediment, different species need different conditions, if fossilized pollen is no longer found in the uk, it shows the climate was different
• evidence for climate change - tree rings

  a tree grows one ring each year, thicker in wet warm conditions

  in the past 70 years rings have become wider suggesting a temperature increase
• evidence for climate change - glacial retreat


  photographs illustrate how far glaciers have retreated in past 200 years due to increased temperature
• natural causes of climate change

  • orbital changes (milankovitch cycle)
  • solar output
  • volcanic activty
• what is the milankovitch cycle?

  the suns energy on earths surface changes as the earths orbit is elliptical its axis is tilted on an angle. it happens every 100,000 years.
• what are the human causes of climate change?

  • fossil fuels - enhance greenhouse effect
  • agriculture - acounts for around 20% of greenhouse gasses due to methane produce from cows
  • deforestation - releases co2 into the atmosphere
• what are the social effects of climate change?

  • increased disease - e.g skin cancer
  • winter deaths decrease
  • less ice in arctic ocean - increases shipping and extraction of oil and gas
  • droughts - reduce food supply and increases water scarcity in the uk
  • declining fish
  • increased extreme weather
  • skiing industry in alps threatened
• what are the environmental effects of climate change?

  • increased drought
  • lower rainfall - food shortages for animals
  • sea levels rise - flooding and coastal erosion
  • ice melts - threatens habitats
  • warmer rivers - affects marine wildlife
  • coral bleaching
• how to mitigate climate change:

  • alternative energy production - will last longer, are expensive
  • planting trees (afforesation) - helps remove co2
  • carbon capture - takes co2 from emission sources and stores it
  • international agreements - targets will only be met if they are legally binding
• how to adapt to climate change:

  • the gambia - suffering from drought, introduced drought resistant strains of crops
  • uk - places limit water usage