Global Warming

Global warming is the gradual rise in temperature of the earth’s atmosphere. The technical term for this is anthropogenic global warming. Anthropogenic means originating from the activity of humans.

Our earth is warmed by the sun’s rays (or radiation). These rays (sunlight) come in through the earth’s atmosphere, where they are absorbed, and are reflected back out to space again, as heat.

Greenhouse Gases

  • The Earth’s atmosphere is made up of layers of gases, some of which are known as ‘greenhouse gases’. They are predominantly natural gases which make up a “thermal blanket” over the earth, trapping enough of this heat in the atmosphere, and letting some of the rays go back out of the atmosphere into space. 
  • This keeps the earth at the correct temperature for humans, animals and plant to survive. The overall average temperature of the Earth is 15/16°C. So the correct balance of greenhouse gases ensures the survival of our planet, and allows for conditions that provide us with air to breathe, fresh water and the weather our survival depends on. (Without these gases, the average temperature would be about minus 18°C!).
  • The “greenhouse effect” is the warming that happens when certain gases in the Earth’s atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse.
  • Greenhouse gases are natural gases made out of: 
      • Major gases:
          • Water Vapour 
          • Carbon dioxide (CO2) 
      • Lesser gases:
          • Methane 
          • Nitrous (Nitrogen) Oxide 
          • Ozone 
          • Chlorofluorocarbons (CFCs)
  • The ozone layer is made up of ozone (a type of oxygen) that protects the earth from too many harmful rays called UVB. 
  • The respiration of animals, volcanic eruptions and decaying plants discharge natural CO2 into the Earth’s atmosphere, where it exists for about 100 years. 
  • It is eliminated from the atmosphere by plant photosynthesis and by dissolution in water (such as in the oceans). This natural carbon dioxide cycle keeps a balance in the amount of CO2 in our atmosphere. But human actions and behaviours can cause changes which upset this natural balance. 
  • When too many greenhouse gases are created, the “thermal blanket” thickens and too much heat is trapped in the Earth’s atmosphere, increasing the overall average temperature – which has a number of devastating consequences. See below.
  • Extra greenhouses gases are produced by humans by our creation of pollution through activities such as burning coal and petrol (referred to as ‘fossil fuels’ or fossil energy)( e.g. power plants, factories and exhaust from cars); the destruction of rainforests and cutting down of other forests; and methane produced by animal waste. Like a circuit board that will blow if overloaded, we are in the process of overloading our atmosphere with heat-trapping gasses!
  • There is scientific agreement that our Earth’s atmosphere is warming and emissions of greenhouse gas pollutants are contributing to that warming. Our Earth will continue to get warmer as the quantity of these pollutants keep on building up in the atmosphere. 
  • Although we cannot stop global warming, we can make lifestyle and industry choices that can slow it down and lessen the effects.
  • We need to slow down our use of fossil energy, in particular coal.

Climate Change

  • The term “climate change” is often used instead of global warming. This is because as the Earth’s average temperature rises, ocean currents and winds move heat around the planet in systems that warm some areas, cool others, and alter the amounts of snow and rainfall. As a result, the climate changes differently in different areas.
  • Climate variability and change, as a result of human activities, is different from the normal climate cycles – the global climate is naturally changeable and there is a natural cycle of variability. But there are now more pronounced/rapid changes in climate and more extreme climate events as a result of human activity such as the increase of CO2 in the atmosphere from burning fossil fuels.  CO2 is caused by us spewing out pollution into the atmosphere.
  • Global warming is the result of increased particulate matter (including CO2) in the atmosphere which reflects the heat back to earth. Global warming is just one aspect of climate change.
  • Other phenomena’s responsible for global warming include volcanoes and solar variations.

Increasing Global Temperatures

  • According to the Intergovernmental Panel on Climate Change (, eleven of the twelve hottest years since thermometer readings became available occurred between 1995 and 2006.
  • According to NASA’s Goddard Institute for Space Studies, average temperatures have climbed 0.8°C around the world since 1880, much of this in recent decades. 
  • Prediction models created by the IPCC, forecast that the global temperature could rise by 1.1 to 6.4 °C between 1990 and 2100. Such increases in temperature will cause climatic changes and extreme weather conditions resulting in rising sea level, changes in the amount of precipitation, above average rainfall, melting of polar ice caps and glaciers, storms and hurricanes.

Consequences of Global Warming

  • If we continue at the current trends and the Earth continues to gets hotter, it is expected that the following could happen: 
      • Sea levels will rise – this is because when water is heated it expands, and our oceans absorb more of the heat than land does.
      • Melting of the glaciers and sea ice will cause sea levels to rise. The flow of ice from glaciers in Greenland has more than doubled over the past decade.
      • Coastal cities would flood, destroying homes, offices, schools, infrastructure etc and displacing millions of people worldwide.
      • It is estimated that the Arctic Ocean could be ice free in summer by 2050.
      • Areas that typically receive lots of rain and snowfall will get hotter and drier. 
      • Heat waves will be more frequent and more intense.
      • Rivers, lakes and dams will dry up. 
      • More areas will become drought- ridden which makes growing crops much more difficult, resulting in less food production. 
      • Wildfires and forest fires will occur more often. 
      • There will be less water available for drinking and cleaning and living. 
      • Animals and plants will become extinct due to the heat. It’s been determined that at least 279 species of plants and animals have moved closer to the poles. 
      • More than a million species worldwide could be driven to extinction by 2050.
      • There will be an increase in coral reef (referred to as rain forests of the sea) bleaching. Bleaching is a drop in algae, which in effect kills the reefs as they are unable to produce food without the algae.
      • Storms, hurricanes and tornadoes – fuelled warmer ocean temperatures and water evaporation will become more prevalent. (The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years).
      • There will be an increase the spread of diseases, such as dengue fever, malaria, hantavirus. Disease-carrying mosquitoes and rodents will spread, infecting people.  Malaria has spread to higher altitudes in places like the Colombian Andes, 7,000 feet above sea level.
      • Deaths due to global warming will double in just 25 years – to 300,000 people a year.
      • Think about how any one or more of the above will directly affect your life. Then realise the impact that all of the above will have on our world.

The United Nations Framework Convention on Climate Change (UNFCCC).

  • The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty that encouraged countries to reduce emissions of greenhouse gas to combat global warming. 
  • It acknowledges that the climate system is a shared resource that is affected by emissions of carbon dioxide and other greenhouse gases by industry and other means.
  • The UNFCC’s primary objective is the “stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system”. (Anthropogenic means originating from the activity of humans).
  • The UNFCCC was opened for signature at the United Nations Conference on Environment and Development (UNCED), better known as the Earth Summit, in Rio de Janeiro in 1992. The Convention entered into force on 21 March 1994.
  • A national greenhouse gas inventory was established whereby a count of greenhouse gas (GHG) emissions and removals must regularly be submitted by signatories of the United Nations Framework Convention on Climate Change.
  • The original treaty set no mandatory limits on greenhouse gas emissions and is not legally binding.
  • However, greenhouse gas emission levels around the world continued to rise. It became clear that a legally binding commitment to reduce emissions was required to commit businesses, communities and individuals to act on climate change. 

The Kyoto Protocol

  • Thus the Kyoto Protocol (which is linked to the UNFCCC, sharing the same objectives, but stands on its own) was formed. 
  • It is an international legally binding agreement that established greenhouse gas (GHG) emission targets for countries. 
  • The Protocol requires developed countries to reduce their greenhouse gas emissions below levels specified for each of them in the Treaty. It commits 38 industrialised countries to cut their greenhouse gas emissions between 2008 and 2012 to levels that are 5.2% below 1990 levels.
  • The Kyoto Protocol (adopted in December 1997 in Kyoto, Japan, and enforced in February 2005) mandates countries to develop more environmentally responsible ways of producing and using energy, in order to meet their targets for reducing greenhouse gas emissions (caused primarily by burning oil, gas and coal and by deforestation).
  • The detailed rules for its implementation called the “Marrakesh Accords” were adopted in Marrakesh in 2001. 

Carbon Credits Trading

  • The Protocol provides for mechanisms to help countries meet their emission reduction targets. One of these was the creation of carbon credits trading. 
  • Companies and other groups are given emission permits, with allowances or credits, to emit a limited amount of emissions. 
  • Organisations needing to increase their emissions can buy credits from others who pollute less than their permitted amount. This transfer of allowances or credits is carbon credit trading.
  • Fifteen percent of the world’s population lives in rich countries, but are responsible for 45 percent of world’s carbon emissions.

Signatories to the Kyoto Protocol

  • As of November 2007, 174 countries signed and ratified the Kyoto Protocol to the United Nations Framework Convention on Climate Change
  • Click here for a list of Protocol Signatories Hyperlink.

Things You Can Personally Do To Reduce Global Warming:

  • Reduce your personal reliance on fossil fuels by:
      • Installing a solar water heater  
      • Creating liftschemes, riding or walking where possible; buying the most fuel efficient vehicles. 
      • Dispose of your waste responsibly, minimising your impact on landfills
      • Recycle; buy recycled products; reuse and re-purpose what you already have.  
      • Spread the word and share what you’ve learnt. 
      • Tell family, friends and colleagues about
      • Learn more and share!

Some scary facts from National Geographic:

  • The 20th century’s last two decades were the hottest in 400 years and possibly the warmest for several millennia, according to a number of climate studies.
  • The Arctic is feeling the effects the most. Average temperatures in Alaska, western Canada, and eastern Russia have risen at twice the global average, according to the multinational Arctic Climate Impact Assessment report compiled between 2000 and 2004. 
  • Arctic ice is rapidly disappearing, and the region may have its first completely ice-free summer by 2040 or earlier. Polar bears and indigenous cultures are already suffering from the sea-ice loss. 
  • Glaciers and mountain snows are rapidly melting-for example, Montana’s Glacier National Park now has only 27 glaciers, versus 150 in 1910. In the Northern Hemisphere, thaws also come a week earlier in spring and freezes begin a week later.

In a U.S. National Academies Report commissioned in 2001, it was stated that:

  • “Greenhouse gases are accumulating in Earth’s atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. 
  • Temperatures, are, in fact, rising… (The) predicted temperature increase is sensitive to … future concentrations of greenhouse gases and aerosols. Hence, national policy decisions made now and in the longer-term future will influence the extent of any damage suffered by vulnerable human populations and ecosystems.”

In a joint statement with 10 other National Academies of Science, the U.S. National Academies of Sciences stated:

  • “The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action. It is vital that all nations identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions.”
  • Joint Statement of Science Academies:
      • Global Response to Climate Change, 2005
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