CARBON DIOXIDE (CO2) and
OTHER GREENHOUSE GASSES
Greenhouse Gases (GHG’s) are those that can absorb and emit infrared radiation from the sun and allow our atmosphere to keep our planet warm. They essentially trap heat in our atmosphere, hence the term 'greenhouse gases'. A little bit of heat in our atmosphere is a good thing - heat prevents ice ages, for example. Too much heat in our atmosphere is a bad thing - it changes our weather and affects all forms of life everywhere.
Below is a list of greenhouse gases in order of most to least abundant:
- water vapor (H2O)
- carbon dioxide (CO2)
- methane (CH4)
- nitrous oxide (N2O)
- ozone depleting gases (such as Chlorofluorocarbons)
Greenhouses Gases are a good thing for our planet when they are present in appropriate concentrations. However, excessive amounts of any one of these greenhouse gases can trap too much heat in our atmosphere and cause Global Warming.
The Greenhouse Gas of greateest concern is carbon dioxide (CO2). It occurs naturally, but it is also the Greenhouse Gas that humans are making more of every time they burn a fossil fuel, unnaturally. CO2 is not bad in itself. What is bad is the increasing rate at which humans emit CO2 (and other global warming pollutants) into the atmosphere.
Since the Industrial Revolution humans have been emitting more and more CO2 into the atmosphere by burning fossil fuels such as coal, oil and natural gas. So much CO2 has been released by this burning that today we have created a very serious problem.
Many climate scientists have agreed that 350 parts per million of CO2 in the atmosphere is the highest concentration tolerable for a healthy balance of life on Earth as we know it. However, current readings of CO2 in our atmosphere range from 390 PPM to 400 PPM.
CO2 concentrations have been much higher at various times in Earth’s history, however, those were times that pre-date human history and would have precluded humans from evolving due to the hostility of the atmosphere. Since the last ice age ended aprox 12,000 years ago, the Earth has had a relatively stable climate. Life as we know it is dependent on this stability and its factors such as CO2 concentrations.
