Dear Holger, I have the impression you simply do not want to face actual facts, since you consider, against all scientific evidence, C02 to have little or no heating effect on the planet. A "higher share would, you seem to believe, be better- true, if you're a dinosaur, false if you're a human. C02 is not a insignificant gas when it comes to warming the planet- it's second only to water vapor.

https://skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect.htm

"Climate Myth...

Increasing CO2 has little to no effect

"While major green house gas H2O substantially warms the Earth, minor green house gases such as CO2 have little effect.... The 6-fold increase in hydrocarbon use since 1940 has had no noticeable effect on atmospheric temperature ... "

(Environmental Effects of Increased Atmospheric Carbon Dioxide)

That is to be your stated belief and is a well-known myth about Climate Change and Global warming. C02 release from burning fossil fuels is no "insignificant". Fossil fuels ARE carbon so just what do you think is released? I'm aware that methane is far more potent as a "green house" gas but primarily because it rapidly breaks down into C02.

Read the rest of the article and look at the charts provided and you'll find that when you refer to ir, you are, of course, referring to infrared radiation- also known as "heat" radiation.

(This time, we see that during the period when temperatures increased the most, emissions of upward radiation have decreased through radiative trapping at exactly the same wavenumbers as they increased for downward radiation. The same greenhouse gases are identified: CO2, methane, ozone etc.) To understand that paragraph, look at the chart above it.

The Empirical Evidence

As temperatures started to rise, scientists became more and more interested in the cause. Many theories were proposed. All save one have fallen by the wayside, discarded for lack of evidence. One theory alone has stood the test of time, strengthened by experiments.

We know CO2 absorbs and re-emits longwave radiation (Tyndall). The theory of greenhouse gases predicts that if we increase the proportion of greenhouse gases, more warming will occur (Arrhenius).

"The connection can be found in the spectrum of greenhouse radiation. Using high-resolution FTIR spectroscopy, we can measure the exact wavelengths of long-wave (infrared) radiation reaching the ground.

These data provide empirical evidence for the predicted effect of CO2."

Are you aware that climate change and warming caused by humans was first postulated and studied 200 years ago? Here is a nice primer:

https://www.edx.org/course/making-sense-climate-science-denial-uqx-denial101x-0