The Science made Simple
Carbon in our planet
For the benefit of those who are puzzled by it all, I have attempted to put together this simplification of the facts that lie behind the science.
Carbon is a solid that can occur in may different forms; it is one of the 94 natural elements that make up everything in our world, an element being a substance that cannot be broken down in to any simpler substance. Diamond is carbon, so is chimney soot, so are we, so are the plants, trees bushes, so are the animals that inhabit our planet which includes us humans, we are all compounds of carbon. These are mainly polysaccharides and carbohydrates, a chief compound being cellulose of which vegetable matter is made up. It is a fact that all life on our planet, both vegetable and animal is carbon based.
An important compound of carbon is carbon dioxide, which is a gas, and its formula is CO2. This means that a molecule of CO2 has one atom of carbon combined with two of oxygen.
Oxygen and carbon are very important to us. We breathe in the air. Healthy lungs remove about 18% of the oxygen, the waste nitrogen and CO2 is exhaled together with more CO2 from our bodies together with water vapour and some other gases. Exhaled breath contains about 5% CO2. One could accurately describe our lungs as a gas exchange system.
Plants absorb CO2 and use a clever process called photosynthesis whereby energy derived from sunlight is used to break down the CO2 into carbon for the growth of the plant, and the oxygen is then put out into the air for the benefit of the animal kingdom. However, when they die and decay they release their carbon by combining it with oxygen to form carbon dioxide. So you can see that there is interdependence between animals and plants for each others sustenance, and that carbon is continuously being cycled as solid to gas and gas to solid. This is called the “carbon cycle”
Our atmosphere is composed of 78% nitrogen, 21% oxygen, 0.96% argon, and 0.04% carbon dioxide. Note the volume of CO2, this is important.
Climate
The source of heat on our planet is the sun, rather like saying “wood comes from trees”, however, without a little help it would be insufficient on its own to maintain our planet in a habitable environment.
What we have is an effect called the “greenhouse effect” whereby certain gasses act to retain the heat absorbed by the earth and prevent it from all just escaping back into space. Surprisingly, the main greenhouse gas is water vapour.
Here is a breakdown
Water vapour 95%
Carbon Dioxide 3.62%
Nitrous Oxide 0.95%
Methane 0.36%
Others including CFCs 0.07%
Obviously, as part of the earth gets warmer, more water vapour will be produced, so there has to be some kind of natural ‘safely valve’ otherwise it would become a self escalating process, with things just getting hotter and hotter.
What we have is cloud, when the amount of water vapour in the upper atmosphere reaches a certain point, it forms cloud which acts as a shield against the sun thereby effectively turning down the heat.
Climate Change
It is a fact that this has been going on for about 120 thousand years; we had an ice age, mini ice ages, warm periods, and many other shorter term fluctuations in temperature.
What is known about recent years is as follows:
Roman times, an general warming, following a cold period, the "pre Roman Cold" phase, by the fourth century temperatures where higher than they are today.
Sixth Century, temperatures drop and it stays cold for three centuries.
AD 900 Temperatures rise, a warm period known as the "Mediaeval Warming" which lasts 400 years.
1300 Temperatures drop leading to 4 centuries of the "Little Ice Age". By 1550 temperatures where at their lowest since the last glaciation
Early 1700s, temperatures rise, 8 of the hottest years since records began in 1659
Later 1700s, temperatures fall and it stays cold until the beginning of the 19th Century, paintings of the time show people skating on the Thames, and Greenland became uninhabitable.
Nineteenth Century, temperatures slowly start to rise, what is known as the "Modern Warming" which is what first spawned debate over changing climate and eventually gave rise to the theory that the activities of man where affecting our climate.
However:
It has been hotter in previous years, such as the early 1700s, the 8 year warm period.
There have also been longer warm periods and cold periods in previous years
Greatest rise in temperatures of this period was 1920 to 1940
1940 to about 1980 temperatures dropped and scientists were asking "Is this the start of a new ice age", this period is known as the "Little Cooling".
1980 onward temperatures again start to rise, this lead to the modern climate debate. In England temperatures in the summer of 2006 reached 36 degrees C where I live.
2007 was a cool summer followed by a mild winter. 2008 another cool summer followed by a rather hard winter, snow fell in November with more snow and ice later on.
2009 was yet another cold summer, followed by where we are now.
Carbon Dioxide
Millions of years ago huge rain forests died, decayed, and became buried by geological action, this is how fossil fuels were created. It has been established that CO2 is a greenhouse gas, so logically, if you produce more of it by say burning fossil fuels, you are adding to the greenhouse gasses and thereby causing the planet to warm up more. What is more, the fossil fuels that you extract from the earth had 'locked away' the carbon removing it from the system, you are now extracting it and putting it back into the system.
Well, not exactly.
Part of the carbon cycle is the fate of living matter when it dies and decomposes. Decomposition is very similar to burning but much slower, and what will happen is that the carbon based material from which the dead animal or plant is composed will break down forming water and the carbon element combining with oxygen of the air to form CO2. So as can be seen here, CO2 is formed quite naturally by animals breathing and by all living matter decomposing when it dies. It is also formed quite naturally by other means such as volcanoes.
So what is mans contribution.
Well, its 3.3%.
So if you want to get a calculator and work out what 3.3% of 0.04% is, well I will tell you, its 0.00132% of the CO2 in the air is made by the activities of man.
Now while we have our calculator out, let’s see what percentage of greenhouse gas is produced by the activities of man.
Its 0.11946% of greenhouse gasses are produced by the activities of man.
More grist for the mill
#1 Isotope readings and some other evidence indicates that millions of years ago, such as in the Jurassic period, that of the famous dinosaurs, CO2 levels where 10 times that of today.
#2 As temperatures increase, so does the rate of decay of dead animal and vegetable matter, thus releasing more CO2 into the air. Cooling has the opposite effect; I guess that this is why we put our food in fridges.
#3 Water has the ability to absorb CO2 forming a weak carbonic acid. It’s therefore logical that the biggest soaks of carbon dioxide are the oceans, however, as temperature increases the ability of the oceans to do this is diminished.
I have not added any opinion of comment to the above, my intention, albeit in an over simplification, is merely to offer an explanation of what is going on in nature in a balanced manner so that the reader can form their own opinions.