Atmospheric carbon dioxide is now approaching 400ppm – four hundred parts per million.
The Earth’s Greenhouse Gas, water vapour, varies between 10,000ppm and 40,000ppm
The human contribution to carbon dioxide levels is not definite, because as the Earth warms up from the “Little Ice Age” the oceans release the gas, however there has been a 10-fold increase in fossil fuel burning since WW2 and humans have disturbed the balance of burning dry vegetation on the planet and this no doubt is contributing to the observed significant increase in this minor trace gas.
While it is a very minor trace gas by volume, carbon dioxide is essential for almost all the plant and animal life on the planet and the biosphere has flourished from the recent increase.
This video goes back to when there were only 385ppm, but still makes a very powerful point – Carbon dioxide is a very very very minor Greenhouse Gas, and to label methane a GHG is just an insult to our intelligence. (note she only counts 10,000ppm blue, water vapour, grains & the planet is 70% ocean & it is 40,000ppm over the oceans)