Bioenergetics is the future, and it could be potentially disastrous if we were to disregard the dangers of a runaway greenhouse effect. If anyone could provide more insight into what Peat's thoughts might be please comment. The evidence in favor of the greenhouse effect is too strong to disregard it so easily.
There is an abundant evidence for anthrogenic global warming- it's one of the most believable and obvious phenomenon regarding humans. People are correct when they say that increasing the CO2 in the air will increase plant activity and thereby count as a boost to the planet's metabolism.
However, this ignores that metabolism is not just food but water and micronutrients, as well. When we do "real world" studies replicating the effect of increased global CO2 on normal plants(ie without the careful grooming of a greenhouse attendant), then we see very different results than greenhouse studies. Significantly lower production than in a greenhouse(still higher than non-added CO2), decreased protein, decreased minerals, and increased production of tannins and, in plants that produce cyanide, more cyanide. Also, the effect of increasing plant growth outside of careful attendance results in soil breakdown, which furthers the loss of nutrients.
How could it be that there was no runaway greenhouse effect during the Carboniferous?
The CO2 during Carboniferous was higher than present day but was itself a significant decrease from previous eras and was decreasing throughout the Carboniferous. It's also worth noting that the Carboniferous is considered to have had a higher avg. global temperature than today until it cooled to about the temperature we have now. This cooling was coupled with increased aridification in areas(higher temps increase humidity and rainfall, etc. from that) and is the reason why there was mass flora and fauna die-off.
The Earth is currently on a galactic trajectory that leads us to receive increasing levels of gamma radiation from the galactic center. The effect is likely small, but it is possible that over a long time period we could see greater cloud density and thus greater cooling of the Earth's surface.
Possibly.
We will need to alter how we relate to agriculture and the planet. I'm personally not too worried about CO2 as much as I'm worried about land policy, pollution, and the social consequences of food scarcity, land degradation, etc.