The green CO₂ level (conclusions)

The temperature induced global greening can fully explain the increase of the atmospheric CO₂ concentration. The main conclusions can be summarized as follows.

The present CO₂ level in the atmosphere is a natural level and fully in line with the total amount of photosynthesis (GPP) and so with the present greenness of the Earth.
Global warming is the main driver for increased natural emissions from the large carbon reservoirs (oceans and soil), and for the greening of the Earth. During warm periods, carbon trapped in soils is released faster than photosynthesis can absorb it, resulting in increasing concentration and more greening.
The temperature dependence of the CO₂ concentration is supported by the strong correlation and unidirectional causal relationship between T and ΔCO₂, and the well fitting model calculations.

Figure 1: The present level in the atmosphere is a natural level

This explanation of the CO₂ increase is in many ways preferable to the existing insight. It is in agreement with the observations, and (in line with Occam's razor) it makes the fewest assumptions. The only possible way to blame humans for the CO₂ rise is to assume a special behavior for human emissions. While all other CO₂ remains in the atmosphere for around 4 years, it is believed that human CO₂ accumulates in the atmosphere and stay there for an extremely long time. According to the IPCC (IPCC (2014)) up to more than 100,000 years. In the explanation given here, there is no need to assume a special (ad hoc) behavior for human CO₂ in the atmosphere to explain the present CO₂ level. The residence time for human CO₂ is not different from any other CO₂ in the well-mixed and uncompartmentalized atmosphere. See further: Human emissions do not accumulate.

No exceptional level

The actual CO₂ level is directly related to the greenness of the Earth. The present greenness is higher than one of two centuries ago, but on a longer time scale absolutely not exceptional. It is very unlikely that in the past 800.000 years the level of greening in terms of gross primary production was never so high as today, and so also the concentration in the atmosphere. Consequently, it is improbable that the ice core records from Antarctica provide an accurate representation of historical atmospheric concentrations.

An example to illustrate this, is the situation 10,000 years ago when there was 50% more forest than today. See the chart in Figure 2 from Our World in Data. The average GPP from forests is larger than from grassland and cropland, so it is fair to say that the GPP was at least as large as it is today. This means that also the concentration in the atmosphere must have been at least as high as it is today, as it is proportional to the down flux. It is therefore very unlikely that the ice core proxy from 10,000 years ago of 280 ppmv is correct.

10,000 years ago there was 50% more forest than today.

It is very unlikely that the ice core proxy of 280 ppmv is correct. — Figure 3: 10,000 years ago there was 50% more forest than today, so the GPP was at least as large as it is today. This makes it very unlikely that the ice core proxy of 280 ppmv is correct. Source: Our World in Data, Keeling Curve.

This illustrates that the given explanation of the green CO₂ level is not in line with the usual interpretation of the ice core records from Antarctica. In the article about the CO₂ hockey stick we will elaborate on the many issues that are involved in the correct interpretation of the ice core records, and that it is improbable that they give an accurate representation of historical atmospheric concentrations.

More CO₂ is beneficial

There is no need to worry about the increasing CO₂ level as it goes hand-in-hand with the greening of the Earth, which is beneficial for humankind in all respects. It leads to more vegetation and biodiversity, less desertification, and increased world food production.

The concerns about global warming are based entirely on the greenhouse effect. The climate models that the IPCC uses, assume that an increase in the amount of greenhouse gases in the atmosphere has a warming effect. From the works of Koutsoyiannis and others we know that the causal relationship between warming and CO₂ is exactly opposite of what is believed by the IPCC: an increase in temperature causes a higher CO₂ concentration in the atmosphere, not the other way around.

If there still is any greenhouse effect, it is much smaller than assumed. The IPCC thinks that a doubling of the CO₂ concentration causes a warming of 1.5 to 4.5 °C. The large margin already indicates that there is a lot of uncertainty about the correct magnitude. The various studies on this subject are far from unanimous. Many researchers have shown that even the lower limit of 1.5 °C is still (much) too high. The climate website NoTricksZone contains summaries of more than 160 scientific articles, all of which arrive at a climate sensitivity that is much lower than what the IPCC assumes, in most cases well below 1°C.

Video

Here you find an excellent video from british member of parliament Robin Horsley on why the fear for CO₂ is so wrong: CO₂ follows temperature, not the other way around.