Implications of Degradation of Water & Carbon Cycles (Edexcel A Level Geography)

Changes in Global Forest Coverage

Deforestation

• An estimated 1.6 billion people depend on forests and more than 90% of these are in developing countries

• Forests are essential for human well-being through their services as well as being the source of 80% of global biodiveristy

The Forest Ecosystem Services

• An estimated 13 million hectares of forests between 2000 and 2010 were affected by deforestation 

• However, the net loss was reduced because of afforestation 

• The environmental Kuznets curve suggests that communities reach a tipping point where exploitation of forests changes to more protection

• The changes in attitudes are usually dependent on:

  • The wealth of a country

  • Increasing knowledge of the role that the environment plays in our well-being

  • Aid given to developing countries to help reduce exploitation

  • Political systems and introduction and enforcement of environmental laws

  • The involvement of locals

  • The power and influence of TNCs

• It is hoped that the sustainable management of forests will reduce deforestation and as a result reduce carbon emissions from forests

• Currently, 18% of forests are classed as conserved

  • Brazil and the USA have the largest National Parks and Forest Reserves

• Successful reduction of forest loss in the long term requires:

  • Protective legislation

  • Community involvement in planning and developing policies

Effects of Increased Temperature

Effects of Increasing Temperatures

• Global warming is increasing global temperatures which affects evaporation rates and increases the amount of water in the atmosphere

• These changes can have impacts on the hydrological cycle, for example:

  • Precipitation patterns

  • River Regimes

  • Water Stores (cryosphere and drainage basin)

The Arctic

• The Arctic plays an important role in global climate, as its sea ice regulates evaporation and precipitation

• The Earth’s cryosphere has already been affected by rising temperatures, for example: 

  • Antarctica and Greenland ice sheets have lost mass and glaciers are shrinking

  • Arctic sea ice and spring snow cover in the northern hemisphere continue to decrease in extent and thickness 

• The Arctic acts as a barometer or early warning system for the environmental impacts resulting from the burning of fossil fuels

  • Arctic temperatures have risen twice as fast as the global average in the past few decades

  • Significant loss of sea ice e.g., the North-west Passage can now be navigated in the summer

  • Permafrost is melting

  • Carbon uptake by plants is increasing because of the lengthening of their growing season

  • A loss of albedo as the ice that once covered the land is replaced by tundra and tundra is replaced by taiga (further encouraging global warming)

Threats to Ocean Health & Implications for Humans

Ocean Health and Impacts on Huma Well-being

• Global warming is affecting ocean temperatures and currents as well as the supply of nutrients and marine food chains

• These changes can be categorised under the following:

  • Bleaching

  • Acidification 

  • Rising sea levels

  • Loss of sea ice

• These changes then have an impact on distribution, abundance, breeding cycles and migration of marine plants and animals which millions of people depend on either directly or indirectly for food and income

• Research suggests that marine organisms may be responding faster to climate change than terrestrial organisms