Carbon Dioxide in Perspective
Carbon dioxide is a trace gas in a dry atmosphere, estimated at 0.0415%, which means 99.96% is not CO2. However, the Earth's atmosphere is not dry, it contains water in it's three states of solid (high clouds), liquid (medium and low-level clouds and fog), and gas in the form of water vapour. Levels of water in these three states has been difficult to estimate. Based on the relative humidity (RH), which is the percentage of moisture of a saturated atmosphere, over the UK for the last 21 years, the average RH is 80.8%. In the Sahara Desert the average RH is 25%.
The IPCC suggest man-made emissions of CO2 accounts for 3% of total atmospheric CO2. Total atmospheric CO2 is 415 parts per million, 0.0415%, (1 part per 2,409), therefore man-made emissions are 3% of 415 ppm which is 12.45 ppm or (12.45/1,000,000), 0.001245%, 1 part per 80,321 other gases.
In the UK man-made emissions, accounts for 1% of the 3% total man-made emission. This equates to (12.45x1%), 0.00001245%, which is 0.1245 ppm or 1 part per 8,032,128
Fig 3 percentage of atmospheric levels CO2 (412ppm), global man-made CO2 emissions (12.4pp) and UK CO2 emissions (0.124ppm).