Global Warming Notes

WHAT, CAUSES, EXTENT, IMPACTS & MEASURES

WHAT is Global Warming?

Global Warming refers to the rise in Air Temperature because of the Increased emission of Greenhouse gases which is the Enhanced Greenhouse Effect. 

             Greenhouse Gases consist of Carbon Dioxide (CO2), Nitrous Oxide, Methane, CFCs

• Carbon Dioxide (CO2) is produced naturally through transpiration by living things and other means such as burning of fossil fuels to generate electricity and the burning of Forests to clear space for buildings and roads. Increase in Carbon Dioxide has led to an increase in temperature on Earth. This causes the glaciers to melt and thus causing the rise in water level.
• Nitrous Oxide is emitted by bacteria in soils and ocean and emitted from vehicles' exhaust.  Agriculture is another cause from the breaking down of fertilizers used for cultivating soils.
• Methane is produced naturally through the decomposition of animal waste. It is also produced by bacteria living in wet rice fields.  
• CFCs - Cloroflurocarbons found in some aerosol sprays, cooling agents in refrigerators. Also produced by foam packaging. 

             All these Greenhouse Gases help to keep the Earth warm by trapping the heat from the   
             Sun's rays.

CAUSES 

>>>>>Enhanced Greenhouse Effect<<<<<

Increased emission of Greenhouse gases which is the Enhanced Greenhouse Effect.

• Increased burning of fossil fuels to generate electricity produces more CO2
• Increase burning of forest to make space for buildings and roads also gives off more CO2
• Increased CFCs due to the usage of large quantities of disposable things used, improper disposal of refrigerators which allows the CFCs to escape. 
• Increased methane from agriculture, raising of livestock and swamps 

EXTENT of Global Warming 

The extent of Global Warming is greater at the north and south poles. 

WHY?                                                                                                                                   At the poles, about 80-90% of Sun's rays are reflected back into space by the ICE (Glaciers). Now with Global Warming and Ozone Depletion, increased melting of ice reduces the amt of Sun's rays being reflected back into space. The increase in melting also results in an increase to the amount of water in the Ocean. Thus the greater the water body (Ocean) the more heat from the Sun will be absorbed....  leading to an Increases in Temperature = Increase in melting of ice at the Poles....  The Cycle repeats. Therefore in the other parts of the Earth, the extent would differ as the presence of the amount of ice is different. 

IMPACTS

• Causes changes in weather conditions such as 
• Prolonged droughts in dry regions as the increase in temperature causes lesser rain to less evaporation, 
• Frequent heat waves caused by the high temperatures and severer flooding in low lying regions due to the raising sea level with more ice melting / with increased evaporation rate that causes prolonged heavy rain in some regions.                                             
• Plants are impacted as the change in rainfall & temperature pattern can affect vegetation growth. 
• Animals are also affected; for example the reduction of polar bears due to the increase in the melting of ice. This reduces it's habitats and causes a reduction of its kind. 
• Humans are affected as the increase in temperature in the tropical region can causes problems like more mosquito breeding which will leads to diseases like dengue and malaria. Humans can also suffer from dehydration and stroke.

MEASURES

INDIVIDUAL

• Helping to reduce emissions of greenhouse gases
• Car pull - A few people to get a lift from another person who is heading to the same place instead of using own cars.                                                                  HOW this helps? This will reduce the amount of fuels burnt and therefore reduce the amount of carbon dioxide released into the air/atmosphere. 
• Using public transport
• Using more energy efficient appliances     

• NATIONAL (Government)

• Using alternate source of energy;
• Promote the usage of hybrid cars (uses electricity and fuel)
• Enforcing laws ans regulations
• Introduce and enforce laws to reduce the emission of Greenhouse gases (Eg. Singapore have laws to control the amount of gases emitted by vehicles. 
• Using products that are more energy-efficient (Eg. In Singapore manufacturers of refrigerators and air-conditioners may apply to Singapore Environment Council (SEC) to have their products labelled for energy efficiency.)
• Reducing Use of CFCs

• To ban the use of CFCs
• New alternatives developed to replace CFCs in cooling agents in refrigerators and air-conditioners. (Eg. In Singapore, since 1995 all new cars imported in are required by law to be equipped with CFC-free air-conditioning systems)

      

• INTERNATIONAL 

• Kyoto Protocol (1997) signed in Kyoto, Japan
• A treaty signed by group of countries to reduce the emission of Carbon dioxide. (some countries refused to sign as this will slow down their industries and thus affect the economy.)
• Singapore acceded to the Kyoto Protocol in April 2006.

• Montreal Protocol 
• A treaty signed by group of countries to limit the production and use of CFCs.