Part Four A Model for CO₂ levels

Carbon Dioxide (CO₂) has been measured very accurately since 1958 By NOAA-ESRL and the trend published monthly; for example this is the chart for January 2015 where the CO₂ level was 399.96 ppm. There is little to no reason to not believe these postings by NOAA-ESRP since they are direct measurements using calibrated equipment at the Mauna Loa location in the Hawaiian Islands.

These NOAA records go back to March 1958 and the pattern seen in the above Chart goes all the way back to that date which is a summer peak and a winter trough. NOAA and others have determined that in pre-industrial times the CO₂ level was in the range of 270 to 280 ppm and then as the use of coal and then oil began the level of CO₂ started to rise. Scientists observing this pattern assumed that all the increase was caused by man, however in ecological times CO₂ has in fact risen and fallen and it appears to follow increases in temperatures and since there were no humans we could not have created these past changes so there is more to this than just a simple CO2 and temperature relationship.

The next Chart shows a diagram of the planet’s Carbon cycle. There is no doubt that man is adding to the CO₂ in the atmosphere but the overall movement of CO₂ into and out of the planet’s atmosphere is significantly great probably by 30 or more also indicating that CO2 caused by mankind is not the main player here. One must also understand that carbon Dioxide is a requirement for plant life and higher levels are better than lower levels. Commercial Greenhouse raise the level of CO₂ to over 1000 ppm to speed up planet growth and 1200 ppm, 3 times where we are at now, would not cause any problems for plants or mankind.

So since more CO₂ is good and less CO₂ is bad for all life on the planet why has it been targeted for removal? Well the only reason is that some have determined that the global temperature of the planet is directly linked to the level of CO₂. Therefore CO₂ must be removed from the atmosphere or we will destroy all life on the planet. This seems to be counter to Nature but Scientists have determined that they know what is really going on in the climate so we must trust them.

This theory of CO₂ being the reason that the Global temperature is going up is based solely on the sensitivity level of CO₂ being 3.0 degrees C as discussed in the previous post; so what we need next is to show what the future level’s of CO₂ will be so we can see if there really is a direct link between CO₂ and global temperature later in this series. The next Chart is of the entire NOAA published CO₂ level from March 1958 to January 2015. There is no doubt that the level is going up and it even seems to be accelerating and the calculated mean level of CO₂ will probably be over 400 ppm by the end of 2015.

In order to make projections into the future we need to model this NASA CO₂ data and the closest fit end up being a form of a logistics curve. If we assume a starting point of January 1600 as 270 ppm for CO₂ than the following equation will produce a curve that matches the NASA-ESRL data mean and goes to 1000 ppm around 2300. This curve fits both historical and projected levels of CO₂ in the available literature.

 CO₂ = 270 + 730 / ( 1 + 8.75 * EXP ( .001733 * (4612 – M )))

M represents the number of months from January 1600 which means that January 2015 is M = 4981 and that gives a CO2 value of 399.98 ppm verses the actual of 399.96 or an error of .02 ppm which is basically no error. The following Chart shows a part of the curve generated by this equation.

There is no question about the level of CO2 in the atmosphere; however there is uncertainty as to the source of all of the increase. But for discussion purposes we will concede that most if not all the increase is due to the use of fossil based fuels, i.e. coal, petroleum, natural gas and wood.

The next issue discussed here will be a look at some historical records on temperatures and CO₂ levels.