If they are sequestering more carbon than they emit, where is all that sequestered carbon going? It might be going into the wood of the forests, but only if the total mass of trees is continuously growing, and fast. If they are merely replacing trees as fast as they cut them down, the best we can say is that activity is carbon neutral. As for the fields, they are not sequesters, because every atom of carbon that gets temporarily incorporated into the plants is, within a year, turning back into CO2 in the form of some animal’s respiration who ate the food, or in the form of decaying compost in the fields. It is very hard to really sequester carbon in any permanent sense. As an aside, burning dead trees does not add to the carbon footprint in the long run. Those trees were going to rot into CO2 whether they are burned or not. So we might as well burn them and benefit from the energy. Fossil fuels are different though, because they started out perfectly sequestered before we mined them or pumped them out of the ground.
I respectfully disagree that forestry is carbon neutral. Tree “farming” certainly does sequester more carbon if one responsibly harvests trees. No question about it, since “adolescent” trees are the big carbon eaters and also the fast growers. Trees vary a lot from species to species and from place to place, but around here, at least, and with the oak varieties (it’s mostly oaks and hickories here) the “fast growers” are the “15x15s”; that is, 15 inches in diameter, fifteen inches above the ground. They can grow more in ten years than a much bigger tree can grow in a century.
But then, unless the forest is neglected, the wood gets turned into houses, furniture, plywood, paper and all sorts of things that do not generally return any significant amount of carbon to the atmosphere.
Timber companies typically have forests in “rotation” all the time. In doing that, they are continually removing carbon from the atmosphere, both in the growth of the trees themselves and in the removal of the wood. Farmers and ranchers who care about their forests tend to do the same thing, but by natural planting in some places like here where the native hardwoods sprout again from the roots of removed trees. It’s true the root systems remain in the ground, but the decaying process is very slow and most of the carbon remains in the ground for a long time.
I will also disagree about grasses. What many do not realize is that the root system is dependent on the blade surface. A person who maintains proper blade height for good photosynthesis is putting a lot of the carbon below the surface of the soil. Roots do change and decompose, but it’s a very long process, depending on the kind of grass one has, because the roots do not die out from season to season. Some of those systems are immense. In addition, proper maintenance of some grasses (particularly some fescues and warm season grasses) are “bunch grasses” that “soil build” by generating woody or nearly woody growth close to the soil surface that stays. As the soil builds, much of the carbon stays.
Studies show that cattle return to the soil about 80% of the nutrients they take in. Sure, they breathe. But they also sequester carbon in their bodies. Humans consume it. Humans die and are buried in concrete vaults.
And the manure and urine do decompose. But they too are “soil builders” and persist as such for a very long time with proper management.
Some practices are superior to others. If, for example, one lets seed stems decompose in the air, there is fast carbon release. If, however, they’re mashed into the ground, they become part of the soil and are very slow to release carbon.
I understand what you’re saying, but my real point was that while CO2 is being released into the atmosphere by a great number of things, it is also being captured. I have yet to see any study establishing that, e.g., the population of the U.S. (let alone Canada) is a net emitter. And none of that even takes into consideration wild animal decomposition into the soil, recycling by meat and carrion eaters, rain, bodies of water, limestone sequestration, improved sequestration through management, or anything else that can affect CO2 in the atmosphere.
