The temperature of Earth is controlled by the balance between input from energy of sun and the loss of this back into space. The energy received from sun is in short-wave radiation; 1/3rd of this solar radiation that hits the Earth is reflected back to space. Of the remaining, some are absorbed by the atmosphere, but most are absorbed by the land and oceans. The Earth’s surface becomes warm, and as a result emits long-wave infrared radiation. The greenhouse gases trap and re-emit some of the long wave radiation, and warm the atmosphere.

  The instrument at Mauna Loa showed a seasonal rise and fall in carbondioxide concentrations, with highest levels being recorded in winter and lowest in summer.

   The story of global warming seriously started with Keeling Curves – Roger Revelle had been trying for some time to persuade his fellow scientists of the importance of monitoring gaseous interactions between the ocean and atmosphere....