Professor Happer presents CO2 as the gas of life, for it is necessary for plant life and therefore all life. In plants take CO2 and sunlight into sugar, as basic element of food energy. With the higher levels of CO2 now the earth has greened. Historically CO2 was at higher levels. Rubisco is a complicated enzyme found in most plants but is destroyed in the presence of a large amount of O2. Therefore, plants have evolved from low to high O2 levels in a manner that you will find interesting. CO2 levels in our lungs are much higher than in the atmosphere. The levels of CO2 that represent a health risk to humans is also much higher than found currently in nature. Submarines face the challenge of reducing CO2. Plants are fed at higher levels of CO2 in greenhouses because of the higher productivity. In higher CO2 levels plants also use less water and can be more productive at higher temperatures as well. This fact contrasts with some media claims.
CO2 is a greenhouse gas, just not a strong one. Professor Happer discusses why the impact of CO2 is small on the earth surface temperature. The effect of CO2 saturates as the amount of CO2 increases even to the 2X amount, such that the change in temperature is small. It is not likely to see the impact of 2x CO2 above 1 to 1.5 C. Exaggeration expands this impact greatly using feedback to achieve the artificial runaway warming. This is not good science.
False popular media want to compare the future earth to Venus which has an atmosphere of all CO2, which has atmospheric pressure 100x that of earth. It also is much closer to the sun and therefore sees more of the sun’s energy. It should be noted that Mars atmosphere is also largely composed of CO2 (95%) but Mars is cold because of its relative distance from the Sun.
Having small amounts of warming is good for the earth and nature.
The political efforts to make the warming from CO2 increases dangerous are intended for obvious reasons to drive energy policies, and it is not scientific or good science.