The author is uncertain of future trends but says that if we needed to raise the earth's temperature we "can release more carbon dioxide into the atmosphere" (p. 141). It seems conservatives were fine with the idea that increasing carbon dioxide increases global temperatures when it helped their argument in the '70s.
I remember those debates well, and your last sentence brought a wry smile.
Just a general observation about these things: we ought to be better stewards, no question. In some ways we collectively have gotten better (I remember the Hudson River was considered too dangerous to stick your toe in, now it is much cleaner; we are much better on air pollution than we were in the 60s, etc.). Other ways, we are perhaps worse. As a once-upon-a-time scientist, I sometimes am dismayed at the alarmism I've seen both on both swings of the pendulum. Rarely is the overarching tendency toward equilibrium (which I consider to be the balancing hand of God) seriously discussed.
For example, I looked at some of the recent CO2 models, and they will say warmer oceans will result in lower CO2 solubility (reducing removal from the atmosphere), but seem to forget other aspects of equilibrium, such as increased plankton growth, which results in increased carbon sequestration.
And so forth....