It depends on how much greenhouse effect there is, how warm the climate is. Everybody knows that the Sun warms up the atmosphere and the Earth, but there are also more things that have influence on how warm it will be. If there was no greenhouse effect, then the average temperate would be 30°C colder than now. The main greenhouse gases are carbon dioxide, methane, dinitrogen-oxide, and chloro-fluoro-carbons (CFCs). These compounds accumulate in the atmosphere and they do not let heat escape toward the space, leading to the warm up of the atmosphere, because more and more heat from the sun gets stuck inside.
The sea level is also changing because of the temperature change. But the climate has always been changing, which lead to the formation of coal. When the seal level rose, huge forested areas became flooded, and slowly thick layers of sediment covered the decomposing organic material. The lack of oxygen, the huge pressure and time lead to the carbonization of these ancient forests, creating the coal reserves of our days.
Oil was formed when creatures in the sea died and sank to the bottom, and then became covered with thick layers of sea sediment. Huge pressure and the lack of oxygen as well as a long period of time lead to the formation of natural gas and mineral oil.
CO2 or carbon dioxide comes when carbon is burned because when it burns it connects with oxygen. When we breathe we release carbon dioxide like all other organisms. However, carbon dioxide also comes from cars, factories and power stations which burn fossil fuels. The amount of carbon dioxide has multiplied in the past 250 years or since the beginning of the industrial revolution in the 1760s.
Another reason for the growing GHG emission is the population boom. There are now 7 billion people living on earth. And all of those people breathe out carbon dioxide and that increase it and all of that people have to eat something and they eat mammals which also breathe out CO2. It also comes when volcanos erupts.
The weather is getting more extreme, both hotter and colder. So we are having hotter summers but very cold winters. All around the world are more extremes in weather, e.g. in the USA there was a strong hurricane called Sandy last year. It hit New York and did a lot of damage to the city.
There have been several floods in Asia that have caused a lot of damage and many million people have lost their houses.
In Iceland in September 2013 was a storm over most of the country and just outside our home town Höfn is an area covered with sand. When cars drove by they got horrible damaged. The storm was so bad that the road spun out of the ground.
Written by Ragnar and Þorsteinn