Natural greenhouse effect versus man made greenhouse effect and global warming.
Learn the basics about climate change and how burning fossil fuels adds extra carbon dioxide to the atmosphere, and how this then leads to climate change.
Fossil fuels, like oil, coal and natural gas, are the remains of living things from millions of years ago. They are mainly composed of carbon with varying amounts of hydrogen. When the petrol burns, it joins with oxygen to build up hydrogen oxide and carbon dioxide.
Before the world became industrialised by burning fossil fuels the carbon dioxide concentration in the atmosphere was about 0.028% tiny compared with oxygen at 21% and nitrogen at 78%, but enough to keep us warm. Without this natural blanket of insulating gas the earth would be too cold to support life as we know it. But this carbon dioxide released when fossil fuels burn adds to the existing carbon dioxide levels which are now nearly 50% higher than pre-industrial times. Although we get a daily supply of heat from the sun, the earth normally loses this (at night and in the colder seasons) so the average temperature of the earth remains constant.
But this status quo is starting to change: as humanity adds carbon dioxide into our atmosphere the extra layer isolates the heat and it cannot escape as easily. The earth cannot lose its greenhouse gases quickly – and we keep adding to them! By putting our planet in a sweat box, we are causing wide ranging consequences for our climate and life on the planet.
Some people think that living things contribute to the enhanced greenhouse effect because they breathe out carbon dioxide – but this carbon has come from their food and that has come from plants which took the carbon from the atmosphere in what is called the carbon cycle. Even burning wood does not contribute to the enhanced greenhouse effect as long as the trees you cut down are replanted.
However the carbon in fossil fuels has remained trapped underground for 100’s of millions of years so it is extra carbon that is being added to the natural cycle. We are also throwing away other gases into the atmosphere which help trap infra-red radiation, and so also enhance the natural greenhouse effect. They are methane, especially from rice paddy fields and from cows and nitrous oxide NON from car exhausts.
This rise in temperature cause our climate to change because extra energy is trapped on earth – already causing glaciers and ice caps to melt. With more energy in the atmosphere weather becomes more extreme, so there are more floods, droughts, and storms. Not everywhere will get warmer, but the climate is changing all because we have been using fossil fuels at an ever increasing rate.
