Trends in Atmospheric CO2 (Carbon Dioxide)

(Source: NOAA's Earth Systems Research Laboratory (ESRL)

The CO2 concentration in the atmosphere rose to 0.040682 in December 2017. Over the last 60 years it has risen varying amounts, as shown in the table of annual mean carbon dioxide growth rates based on globally averaged marine surface data, averaging about half of 1% per year in the last half of the period (Note: Unc.=Uncertainty). The full data record is at NOAA.

Latest CO2 - Global concentration is shown on the right.Recent Global CO2 Monthly Mean

These data have been used by those scientists and their followers who believe in CO2-caused warming to show the Earth is in grave peril. They are also used by those scientists and their followers who are "un-believers" to prove CO2 and Earth temperatures have no causative correlation. Few people realize that argon (.934%) is 22.5 times more abundant than CO2 (.04%). While the "warmists" advise of the perils from rising sea levels and crop changes and new or enhanced disease vectors, the "unbelievers" believe the "warmists" are being ingenuous for being one-sided. "Unbelievers" remind us that CO2 benefits agricultural production because it is essential to plant growth and reduces the need for water. It is essential to feeding a burgeoning population. Further, if CO2 does raise temperatures, food production areas and seasons will expand and be more humid. They believe the greening of the Earth reported by color imaging satellites and the increasing agricultural production is due to CO2 increases shown in the chart.

The meaning of CO2 increases (and the future of all climate models based on it) became VERY cloudy on 31 December 2009 with the ScienceNews acknowledgment of work by Wolfgang Knorr that shows "No Rise of Atmospheric Carbon Dioxide Fraction in Past 160 Years"

The implications of this have yet to be assimilated by the modeling community. This does not mean that CO2 proportion is not rising but rather that the proportion not being assimilated has not changed since 1850. Since most of the projections we are concerned with are based on the IPCC IS92a model, or one of its cohorts, and the concept of CO2 sink saturation, we should give the information on its impacts a second look. Certainly the predicted rapid acceleration of the IS92a model is missing from the NOAA data plotted below, as is an accelerated rise in temperature. However, there is some modest acceleration as one might expect with an expanding, energy-hungry population and economy.

In the Cretaceous period, the dinosaurs and plants lived during a time with CO2 levels about 5 times higher than today. We are still burning the fuels created during that era. Before the time of the dinosaurs, CO2 is believed to have been up to 15 times higher - some 6,000 parts per million. It can be argued that burning fossil fuels is restoring the atmosphere's balance disrupted by their sequestration of CO2.

(Chart Source and related information is at: NOAA's Earth Systems Research Laboratory (ESRL))

Analysis: CO2 continues to rise, but it is a very small part of the atmosphere at 0.000407 globally. Argon is 22.5 times more abundant. CO2 must be doubled eleven times to round to above 0%.

The average growth over the last 30 years has been about 2 ppm (parts per million). In contrast, one of the most commonly used emissions scenarios IPCC 1992a (IS92a--business as usual), projects a much more rapid rate of growth that would have us at 712 ppm in the year 2100. This would require the atmosphere to more than double the present rate of growth of CO2, yet the growth rate seems to be fairly steady at about 0.5%/year. The meaning of this information (and the future of all climate models based on it) became VERY cloudy on 31 December 2009 with the ScienceNews acknowledgment of work by Wolfgang Knorr that shows "No Rise of Atmospheric Carbon Dioxide Fraction in Past 160 Years". The implications of this have yet to sink in the modeling community.

For several years, we have conducted an informal poll, asking citizens what percent of the atmosphere is CO2? No one has ever guessed at lower than 5% and the highest has been 60%, and nearly everyone of these people have been highly educated, concerned citizens. One has to wonder why people are not told of the low abundance of CO2. It is likely because a doubling to 0.08% (0.0008) would not seem very impressive to the public when argon is nearly 1%. Many physicists and engineers are likewise not impressed. It would help if there were broader agreement between models and observations.

Another conversation with someone concerned about all the CO2 goes like this: How much Oxygen is in the atmosphere in percent? Answer: 20.9% (0.209); Nitrogen?: 78.1% (0.781); Argon ?: 1% (0.00934) - Total 100% (0.999). Uh oh. 100% is full. No more room and then we have all these other gases ---- All the other gases? (Neon 0.002%; Helium 0.0005%; Methane 0.0001786%; Krypton 0.0001%; Hydrogen 0.00005%; Ozone 0.000004%). Not much room is left for CO2's 0.04% (0.00041). Most people seem to think it is about 20%.

Our view is that the sun is probably the big gorilla in the room, just like the furnace in your home. This does not mean it is OK to foul our nest through polluting the environment with soot and hazardous chemicals. But, if CO2 is warming the Earth, your furnace and wallet will get a break and more of the Earth will be habitable, fishable and farmable. From a fisheries perspective, distribution will change but production may increase because fish and all they eat grow faster when the water is warmer. For those in freshwater high latitude rivers, summer heat-stress mortalities can be compensated by reduced freezing. If in doubt, consider the biodiversity of warm water habitats vs the edge of an ice-shelf.


This page updated or reviewed in February 2018