There are many sources of Carbon Dioxide. It is a gas that occurs naturally - always has. But the burning of fossil fuels produces a Carbon Dioxide that is identifiable as different from say human exhalation. The systems of the Earth are adept at dealing with the exhalation of Carbon Dioxide and other natural sources - Foliage drinks in CO2 and emits oxygen. We all know this. We should also know that there are scientific methods of measuring the content of the atmosphere and discriminating between different sources of Carbon Dioxide.
So is there an increase in CO2 in the Earth's Atmosphere? Well there should be - there are many more people breathing it out and there are less trees to absorb it - right? More asphalt and buildings where green foliage once existed? We can see through GOOGLE EARTH the massive clear-cutting in major areas of forest across the planet. It's interesting to download Google Earth and "fly over" to see for yourself these areas that were once massive forests or jungles now 50% and more decimated by clear-cutting.
|North of Vancouver|
We also know that the Oceans are excellent CO2 sinks - meaning they can absorb and hold Carbon Dioxide in massive amounts. So it's not necessarily idiotic to assume that our burning of fossil fuels might not have enough impact on these systems to cause a problem
So Scientists began measuring the amount of Carbon Dioxide in the atmosphere decades ago - along with measuring the amount of CO2 trapped in air pockets in ice cores and sediment samples on the ocean floors to get a picture of the historical amounts of those gasses in our atmosphere.
|Atmospheric CO2 Concentrations at Mauna Loa in ppm|
The graph above charts the steady rise of measurable Carbon Dioxide from 1958 thru 2003.