Global warming

One of the greatest threats on earth nowadays is 'global warming'. Global warming is a condition which temperature of earth rises more and more since the heat of sun is reflected back to earth surface, not to atmosphere. The reflection happens because of Carbondioxide layer at atmosphere, while the Carbondioxide itself is produced from natural and human being activities. This such conditions is also called 'Greenhouse effect'. This global warming will cause hunks of ice melt, then surface of sea water will rise. If the warming continues, just try to imagine the dangers which threaten human being on the planet, called earth.