As we continue our series on the effects of refrigeration on the environment, it is wise to give an overview of Global Warming or Greenhouse effect.
The Sun’s rays travel through space (which is a vacuum) more or less uninterrupted (except for hitting a few other particles). They have energy in the form of heat and light. These rays are known as radiation. The Sun is just one big mass of heat, billions of times stronger than a Nuclear weapon. The radiation particles that leave the sun spread out so that their density decreases the further travelled. If this was not the case then the Radiation would be so intense it would be the same as being beside the Sun.
The radiation first reaches the earths’ atmosphere which is denser than space. The atmosphere absorbs some of the radiation. In fact the Ozone plays a critical part in filtering out this. The heat which does reach the earth has an energy of circa 140W per meter squared at the equator. This heats up the surface creating our winds.
However some of the surface heat is radiated back up to space but they have lost energy. There has been an effective balance between what has been radiated out in to space versus what has come in to our planet for millions of years, ever since enough Ozone was created from the plant life within the sea.
Over the past two hundred years, human beings have been producing greenhouse gases, notably Carbon Dioxide or CO2 from the burning of fossil fuels. These gases have a “greenhouse effect” in that they prevent the surface rays from radiating back into space as the atmosphere becomes more dense due to the presence of these gases. The net effect is that the atmosphere heats up.
There are many greenhouse gases, some of which are naturally occurring such as water, carbon dioxide and methane. We have also added other man-made greenhouse gases, such as nitrous oxides (NOx) and fluorocarbons (FCs) and Hydrofluorocarbons (HFCs)