The long wave radiation goes up, but the glass keeps it inside and later on the temperature in the greenhouse rises. Earth works on the same principles. Instead of the glass we have atmosphere with the mixture of gasses e.g. water vapour and carbon dioxide. Those gasses are responsible for reflecting the heat back to Earth (usually 95% of the long wave radiation goes into space).Until 20th century we didn't have problems with high concentration of the greenhouse gasses in the atmosphere. As the evolution of civilization and industry sped up, the use of coal and fuel also increased.

In March 5, 1993 World Meteorological Organization announced that, because of high concentration of carbon dioxide and other gasses after explosion of Pina Tubo volcano, 21% of heat is deflected instead of average 4%.

In the next years some scientists came to conclusion that there will be a big change in temperature. Some say that over the next century world's average temperature will rise ranging from 3,8oC to 6,9oC. Such effect may cause dangerous changes in climate. For example polar glaciers can melt which in effect will rise coastal waters and flood some of the flat lands. It can also destroy the Gulf stream, which brings heat to Western Europe. If such an event happens in Great Britain in winter, weather would be similar to that in Greenland.