I... I am not too sure if I believe in Global Warning... I am not sure it's something we are all doing to the world... Has the world not changed over the last 1000 years... All the science books told us there were icebergs everywhere, then they started to melt... I am not a very educated person, But I think the earth changed over the years... We may not be helping it, but I don't think we are causing all the earth's problems...
Mike, there are two heat engines that cause the Earth to be the dynamic planet that it is.
The first heat engine is internal. The core is still hot and below the earths crust the mantle is plastic and there are convection currents that cause the continents and the sea floor to drift about very slowly, causing earthquakes and volcanoes. This is not affected in any way by what humans are doing and we have no control over any of this. All we can do is to use instruments to monitor what is happening. If the earth was not responding to the internal heat engine in this way erosion would have long ago levelled the surface and the whole planet would be under water.
The second heat engine is external. The Earth, like the Moon, receives radiant heat from the Sun which is absorbed by the land, the oceans and the atmosphere. The heat absorbed is also radiated back into space which is good, otherwise Earth would cook like a pig on a spit. The Earth has an atmosphere that acts as a kind of blanket, maintaining temperature levels, depending on latitude, that are within the range that support life in the many forms that we are familiar with.
The critical gases that help maintain ideal temperatures, not too hot and not too cold, are the greenhouse gases. They are only a very small percentage of the composition of air but they are very important. Too much and the planet heats up. Too little and it begins to cool.
Carbon dioxide is the most important of the greenhouse gases. It is produced when anything that contains carbon atoms decays or is burned. It is produced when animals breathe out, or when limestone is dissolved in acidic water. Fortunately, carbon dioxide is also taken out of the air by plants. They use it to make food from the CO2 molecules and a cycle has been set up on this planet whereby oxygen is used up and CO2 is produced when animals breathe (or decay etc) and CO2 is used up and oxygen is produced by plants as they grow. In this way, the Earth's average temperatures are kept fairly steady over time.
It is more complicated than the simple picture I have outlined but since the Industrial Revolution a couple of centuries ago, the steady state has been disturbed. We have cut down so much of the world's forests that used to absorb CO2, we have dug up the coal, which is essentially fossilised wood, to fire the furnaces and to generate electricity and in doing so, have released enough CO2 to change the percentage composition of air enough to hold more heat in. When the internal combustion engine became popular, we relied on petroleum, which is the fossilised remains of huge amounts of marine organisms, for transportation and we have been happily belching out CO2 from the exhausts of our cars, trains, ships and aeroplanes ever since. Industrialisation has been the cause of upsetting the natural balance that we now see in changes to weather patterns, in climatic changes and in the magnitude and frequency of fires, storms and cyclones and flooding. It is the reason why glaciers have been retreating world wide.
Can we reverse the process? Theoretically, yes. However, unless we try we will never know. Once a new balance is established we may not have the liveable planet we know and love. Life will certainly continue but civilisation could collapse. When life become difficult, arable land is fought over, mass migrations take place and peace evaporates. If nuclear war breaks out, global warming will be the least of our worries.
What must we do? The short answer is find some other way to make electricity, cook our food, heat our buildings and drive our engines other than burning fuel that contains carbon atoms. We must decarbonise on a huge scale with every country doing its part. We've left it very late, ignoring the old maxim that a stitch in time saves nine. Had we acted sooner we would be in a much safer place now. Now it is all hands to the pump, m'lads, or the house is lost.
Does all of the above help?
