Chaparral wrote:Ludi's right on this one.
Tallgrass of various species grows (or rather, grew) in a somewhat cool and dry biome on the interior of N. America just west of the Mississippi. Decomposition of dead organic matter is slowed by the cooler temperatures and lower moisture levels. When the sodbusters started cultivating the plains they had upwards of 3 meters or 10 feet of topsoil composed of that accumulated dead organic matter in places. Every year more organic material would accumulate than was degraded by respiration.
If this solution were tried in Brazil it would not work; there is too much precipitation and the temperatures are too high. The nutrient cycling is too fast in the tropics. If it were tried in Australia, the higher temperatures there might hasten decomposition and hence CO2 or CH4 return..who really knows. It would probably work in the Ukraine or the steppes of Asia.
OK, that 3 m of accumulated topsoil occurred without any methane production, right?
Temperature and humidity certainly make a difference to the rate of anaerobic decomposition but they make no difference whatsoever to the fact that all carbon absorbed by photosynthesis will, sooner or later, be re-emitted into the atmosphere (there may be a few exceptions, such as in cases of subduction of vegetable matter, but this is not valid in this context). The question is whether it is emitted as carbon dioxide or methane. Just 2 - 5% of it being emitted as methane doubles the greenhouse gas emissions. It may surprise you to know that about 115 teragrams of emitted methane arise from natural growth, obviously mainly in wetlands This compares with "only" 45 Tg from natural gas exploitation and a total of 530 Tg from all sources [Tetlow-Smith, 1995].
As for your photo/caption, this displays only your ignorant misconception of what I've been trying, vainly it seems, to tell you. All I have said is that long-term vegetable sequestration of anthropogenic carbon is a myth.
At this moment there are about 550 Gt (billion tonnes) of carbon in land biota, mostly in vegetation. This absorbs 102 Gt from the carbon dioxide in the atmosphere and releases 50 Gt back directly to the atmosphere. A further 50 Gt goes into soil and detritus, which stocks 1500 Gt but releases 50 Gt into the atmosphere. This leaves 2 Gt unaccounted for and this is largely washed down into the sea via rivers with a small amount going into rock formation. [Sundquist et al. 1990]
OK, you question my qualifications. From 1988, I have worked with and for the United Nations Environment Programme and the Swiss Federal Office for the Environment, Forests and Landscape (BUWAL), prior to that the corporation I founded in 1975 was concerned with environment in industry. I have worked with some of the leading atmospheric scientists in the world on both the chemistry and physics of the air we breathe. I have formal qualifications in engineering, chemistry, physics and toxicology. I have written many technical papers and books (some co-authored) related to the environment in some way or another and have worked and lectured in many countries in all continents except Australasia and Antarctica. I have received awards and citations for my work from the US EPA, the US Navy, the IPC, UNEP and elsewhere. I have also sat on ISO, UNEP and IPC committees. Capisci?
(My apologies to others for the trumpet-blowing, but this Ludi guy claims to know more and have more experience than I in the field, without explaining his qualifications other than owning 5 acres of land)