YOUR VIEWS

IN response to the multitude of misinformation and ignorance regarding the science behind global warming and climate change, here is the explanation. There are three gases that are responsible for the warming of the earth: CO2, Methane CH4, and water vapour.

The sun produces two main forms of radiation: Ultra Violet (UV) radiation and Infra-red (IR) radiation. IR radiation, when it strikes objects on the surface of the earth, two things happen to it. Some is absorbed and some is reflected.

Some of the IR is converted to heat on the way in to our atmosphere by way of the CO2, CH4, and water vapour. Now, with IR, when it is absorbed, it is converted to heat, so objects become warmer. What about the reflected IR? Well, it heads back into space under normal circumstances except if there is something in the atmosphere that can absorb it. This is where we get to CO2, Methane CH4, and water vapour. Now CO2 has been at 0.03% in our atmosphere for most of the last 2000-plus years.

A more accurate measure of CO2 is to talk about it in Parts Per Million (ppm). The levels had been at or below 300 ppm for the last 800,000 years. Since 1950, the level has been dramatically increasing where it hit 416.46 ppm in February this year. Couple this with the increasing levels of CH4 through animal raising and we have a big problem. CO2 absorbs some of the IR as it enters our atmosphere and creates heat. Under a ‘normal’ atmosphere the reflected IR would head back into space with some also absorbed on the way out giving a bit more heat. With the increased level of CO2 and CH4 in our atmosphere, more is absorbed on the way in and more is absorbed on the way out, thus causing a rise in the earth’s temperature (the Greenhouse Effect).

Why does CO2 and CH4 absorb the IR? These gas molecules, because of their molecular structure, can absorb energy from infra-red (IR) radiation and generate heat. Not all gas molecules in our atmosphere are able to absorb IR radiation. For example, nitrogen (N2) and oxygen (O2), which make up 99% of Earth’s atmosphere, are not able to absorb IR and so do not trap heat.

Now I did say that this process of the Greenhouse Effect which creates global warming leading to climate change was a complex process. I hope that this explanation helps you understand that this is not hocus pocus. This is not fantasy and that we must act sooner than later to reduce our CO2 levels before it is too late.

JIM TAYLOR, MUDGEERABA

MY letter to GCB 13/08 regarding the egg shortage was not promoting cage eggs, it was merely stating the fact that to meet the demand for eggs cage laid eggs have to be part of the supply chain.

Free range eggs can never meet the demand.

And by the way Mr Cunneen, don’t anthropomorphise.

J. W. M. HALL, HELENSVALE