Global environmental issues and Kyoto Protocol

Since modern life style was started with many home appliances such as refrigerator and air conditioner, the quality of our life improved dramatically. However, refrigerating medium at that time was either sulfur dioxide or methyl formate, which is either highly toxic or flammable. To replace such dangerous gases, Chloroflourocarbon (CFC) was introduced in 1930s. Because of their stable properties, CFCs called Freon had been used widely from refrigerating medium to fire extinguisher to cheap solvent. Unknown to then scientists, Freons were migrated from atmosphere to stratosphere, or the ozone layer. With strong UV light from Sun, Chlorine atoms were freed from CFCs and they started to destroy the ozone layer seriously. To prevent clear and present danger from above, international treaty was set up and CFCs were banned to produce. This treaty is called “Montreal Protocol.” Similar situation is now repeating to Earth. It is called “Global Warming.” It is believed to be triggered by so called green house gases (GHG: mostly carbon dioxide and methane). Another international effort, called Kyoto Protocol, to reduce the concentration of such GHGs is undergoing. We will discuss about what is Kyoto Protocol and how much it will influence to our future.