A key point of the previous post is that political efforts focus on emissions reduction rather than their elimination through better technology, and that this is so because emissions control can provide a revenue stream and increased power, the true aims of politicians.

A similar pattern exists for CO2 sequestration. Politicians dream of major projects to capture carbon from fossil fuels, especially coal, and store it. This is another power and profit lever for governments. But, as with the mistaken energy focus, this is a mistaken carbon sequestration focus. The carbon that we should be concerned about is that which is already in the air. There's plenty of it - enough to have caused some change already and cause more change in future as the inertia of the climate system is overcome by time.

This means air capture rather than smokestack capture. An old post discussed a Freeman Dyson review of some recent global warming books and found them defficient since they failed to engage reality.

There is a famous graph showing the fraction of carbon dioxide in the atmosphere as it varies month by month and year by year . . . It gives us our firmest and most accurate evidence of effects of human activities on our global environment. The graph is generally known as the Keeling graph because it summarizes the lifework of Charles David Keeling, a professor at the Scripps Institution of Oceanography in La Jolla, California. . .

The graph has two obvious and conspicuous features. First, a steady increase of carbon dioxide with time, beginning at 315 parts per million in 1958 and reaching 385 parts per million in 2008. Second, a regular wiggle showing a yearly cycle of growth and decline of carbon dioxide levels. The maximum happens each year in the Northern Hemisphere spring, the minimum in the Northern Hemisphere fall. The difference between maximum and minimum each year is about six parts per million. . .

At every latitude there is the same steady growth of carbon dioxide levels, but the size of the annual wiggle varies strongly with latitude. . .

The only plausible explanation of the annual wiggle and its variation with latitude is that it is due to the seasonal growth and decay of annual vegetation, especially deciduous forests, in temperate latitudes north and south. The asymmetry of the wiggle between north and south is caused by the fact that the Northern Hemisphere has most of the land area and most of the deciduous forests. The wiggle is giving us a direct measurement of the quantity of carbon that is absorbed from the atmosphere each summer north and south by growing vegetation, and returned each winter to the atmosphere by dying and decaying vegetation.

The quantity is large, as we see directly from the Point Barrow measurements. The wiggle at Point Barrow shows that the net growth of vegetation in the Northern Hemisphere summer absorbs about 4 percent of the total carbon dioxide in the high-latitude atmosphere each year. . .

When we put together the evidence from the wiggles and the distribution of vegetation over the earth, it turns out that about 8 percent of the carbon dioxide in the atmosphere is absorbed by vegetation and returned to the atmosphere every year. This means that the average lifetime of a molecule of carbon dioxide in the atmosphere, before it is captured by vegetation and afterward released, is about twelve years. This fact, that the exchange of carbon between atmosphere and vegetation is rapid, is of fundamental importance to the long-range future of global warming . . .

This casts the longevity of CO2 in the atmosphere in a different light. When it is said that it is a long lived gas that takes perhaps 100 years to break down this refers to chemical decay rates. But no individual molecule stays in the air that long if, as Dyson notes, it is captured and re-emitted many times in 100 years. What can we do to keep them captured rather allowing them to escape again?

This is related to other troubles and threats to our health, wealth and longevity. The loss of carbon from soils and vegetation, especially forests and grasslands, is a large contributor to the current atmospheric surplus, and impoverishes the phyto-sphere as well. And as with energy, our need isn't to minimize loss it is to increase production. We need to do more than restore lost carbon to our soils and vegetation, we need to increase it above historic levels. This will not only reduce the troubling amounts of carbon in the air (and seas etc.), it will enhance the land, making it more productive of the food, fiber and chemicals (including some fuels) that we need to provision our large and growing population of humans. We need more energy, we need more food, and these things are related.

Known methods to do this include common themes here, such as biochar, but that isn't enough. The basic need is to increase the amount of phytomass produced, and that requires energy for vegetation - plant food in other words. Carbon rich soils can make existing nutrients more available to plants, and lose less of them to erosion and leaching, but more is required. We have to manufacture or mine sequestered nutrients in order to sequester more carbon. There's a pleasing symmetry in this: the sequestered carbon that we have dug up and released into the current working set must be balanced by also digging up sequestered minerals that enable plants to suck the carbon back down into the ground. Happily, this will also provide us with the food, fiber and chemicals we need.

I don't mean to imply that this will be quick or easy. It will take many years to deploy such systems to a meaningfully large extent, and many years of operation to achieve the desired ends. What I'm saying is that adding even more years on the front end while we stumble around with political shenanigans is a waste. What we are doing now is running in circles with our tails on fire, which is pleasing to politicians but does nothing helpful.