HOME/The greenhouse effect - causes, consequences

3. The greenhouse effect - causes, consequences

What is the greenhouse effect?

The word 'greenhouse' is associated with artificial warming and it is used to describe the artificial warming of the Earth's atmosphere - similar to a greenhouse used to grow fruit and vegetables in the cold winter months.

Earth's atmosphere acts like a blanket and traps heat from the sun to ensure the planet is warm enough to sustain life. However, as we burn fossil fuels (coal, oil and gas) to generate electricity, we are producing large amounts of carbon dioxide (CO2), and other chemicals that are adding to the natural warming of the atmosphere. Other man-made chemicals and pollution also increase the warming effect.

greenhouse gas emmissions(Click to enlarge)

Refrigerants like CFC's, HCFC's and HFC's are all greenhouse gases (GHGs), and they contribute to Global Warming.

What is global warming?

Global warming refers to the 'enhanced greenhouse effect', and as chemicals and gases make their way into the atmosphere, they act like a thick blanket that traps the sun's heat, and increases the temperature of the planet.

Impacts of global warming - the facts:

  • Global warming is melting glaciers increasing the risk of floods, droughts and shortages of drinking water,
  • Scotland's hottest year on record - in 2003 - killed hundreds of adult salmon as rivers became too warm for them to extract enough oxygen from the water,
  • Summer temperatures in European capitals have increased by up to 20C over the past 30 years,
  • Rising sea levels threaten entire nations on low-lying islands in the Pacific and Indian oceans,
  • The report 'Global Warming contributes to Australia's worst drought' released by WWF and leading meteorologists shows that human-induced global warming was a key factor in the severity of the 2002 drought in Australia, generally regarded as the worst ever.
  • On September 16 2012, Arctic sea ice appeared to have reached its minimum extent for the year of 3.41 million square kilometers - the lowest seasonal minimum extent in the satellite record since 1979, (Arctick Sea Ice News, October 2, 2012).

(WWF, 2012)

Other effects of global warming include:

  • More hot days,
  • More severe weather events - storms, floods, droughts and fire,
  • Higher sea levels,
  • More hurricanes and cyclones in the Caribbean, the United States and Burma,
  • More extensive droughts in eastern Africa, Australia, southern Europe and parts of China and India, and
  • More devastating floods like those in Pakistan (in 2010), Brazil and Australia (in 2011), and other parts of the world.

(WWF, 2012)

Global warming is forcing the Earth's climate to change. To read more on climate change and global warming, and to find out what the Australian Government is doing about it, visit www.climatechange.gov.au