So now we have a few facts and figures, let’s get an idea of how this looks when we actually see CO2 as it is in real life. After watching the video, please close its window and continue reading.
Let’s look now at the cAGW hypothesis, which proposes that as CO2 is a ‘Greenhouse Gas’ humans continually pumping unrestricted tonnes of it into the atmosphere will lead, inevitably, to catastrophic heating of the atmosphere and result in the end of the world as we know it. In fact, the anthropogenic increase into the atmosphere, on an annual basis, is only ~2 ppm (two parts per million). Increases from Natural sources, such as plant respiration, account for virtually all the rest. Here is a reasonably even-handed explanation of the Carbon Cycle which also covers many other aspects of how the planet lives and breathes.
The question then arises, if mankind’s activities add so little to the huge natural CO2 movement into and out of the atmosphere, why all the ‘song and dance’ and why hasn’t the hypothesis been de-bunked? That, I’m afraid, is where we move into the area of politics and that must wait for another section altogether. Some aspects of the carbon cycle are accepted as given but once one looks at the actual numbers, the less one is inclined to accept the hypothesis. For example, until relatively recently, I had no idea of just how important are the oceans’ role in the planet’s carbon cycle. There is approximately 50 times more carbon in the oceans than there is in the atmosphere; and there is a constant interchange which can span several hundred years. Nearly half of all the CO2 released into the atmosphere by human activity is taken up by the ocean.
And don’t forget that we rely on photosynthesis by marine plants for at least 50% of the oxygen we breathe.