Methane fears

We have had a lot of enthusiasm for methane lately for its potential as a so called greenhouse gas.

http://www.physicalgeography.net/fundamentals/7a.html

Methane is a very strong greenhouse gas. Since 1750, methane concentrations in the atmosphere have increased by more than 150%. The primary sources for the additional methane added to the atmosphere (in order of importance) are: rice cultivation; domestic grazing animals; termites; landfills; coal mining; and, oil and gas extraction. Anaerobic conditions associated with rice paddy flooding results in the formation of methane gas. However, an accurate estimate of how much methane is being produced from rice paddies has been difficult to ascertain. More than 60% of all rice paddies are found in India and China where scientific data concerning emission rates are unavailable. Nevertheless, scientists believe that the contribution of rice paddies is large because this form of crop production has more than doubled since 1950. Grazing animals release methane to the environment as a result of herbaceous digestion. Some researchers believe the addition of methane from this source has more than quadrupled over the last century. Termites also release methane through similar processes. Land-use change in the tropics, due to deforestation, ranching, and farming, may be causing termite numbers to expand. If this assumption is correct, the contribution from these insects may be important. Methane is also released from landfills, coal mines, and gas and oil drilling. Landfills produce methane as organic wastes decompose over time. Coal, oil, and natural gas deposits release methane to the atmosphere when these deposits are excavated or drilled.

Table 7a-1: Average composition of the atmosphere up to an altitude of 25 km.

Gas Name	Chemical Formula	Percent Volume
Nitrogen	N2	78.08%
Oxygen	O2	20.95%
*Water	H2O	0 to 4%
Argon	Ar	0.93%
*Carbon Dioxide	CO2	0.0360%
Neon	Ne	0.0018%
Helium	He	0.0005%
*Methane	CH4	0.00017%
Hydrogen	H2	0.00005%
*Nitrous Oxide	N2O	0.00003%
*Ozone	O3	0.000004%

I want you to observe that everything in this list is at its lowest oxygenation level with the sole exception of methane. Also observe that CO2 is 200 times more available. This is true because methane is almost as good a rocket fuel as hydrogen. We usually call it natural gas when we use it to heat our homes. In fact, it is the one gas that has all the cards stacked against its survival.

Even with all the rice paddies, termites and cows hard at work producing methane and all the plants on earth consuming CO2 and nothing consuming methane except oxidizers, CO2 content exceeds CH4 content by a factor of 200.

This entry also makes the claim that since 1750, methane content has increased 150%. Who was measuring? Most certainly this has to be an educated guess linking human population growth and normal related agricultural usage to the current regime. In other words, rubbish has discovered a neat new way to produce methane.

The point is that CH4 is produced in normal biomass combustion and almost as swiftly consumed. This is not true at all for carbon dioxide.

Yesterday we addressed sustainable biochar production. Much concern was expressed over the production of combustibles like CH4 that will escape into the atmosphere. And a natural earthen field kiln will lose a lot of combustibles in this manner and not just methane. My description of the inexpensive modified incinerator design took advantage of that out gassing to fuel a second high temperature oven whose heat was then used to accelerate the carbonization process.

That solution is possibly available to industrialized agriculture. It is certainly not an option for everyone else, and may be suspect even were the equipment is available. Of course even more expensive systems can be deployed for a very small incremental gain.

The point that I want to make is that the primitive earthen kiln and my incinerator are separated only by efficiency. I would reasonably expect perhaps twice as much product to be produced. This cannot be accomplished with a sharp increase in haulage costs. I also point out that the jury is truly out as to the quality of the end product. The kiln promises to produce a more uniform end product but that may not be as advantageous.

In either case, gases are produced once a year for any plot of land and are then swiftly mopped up by the local environment.

The objective after all is to put carbon into the soil for a long time. Both these techniques do just that. The only other technique that convincingly does the same thing is the growth of new forests. Every other agricultural process that we have created is in a constant struggle to just maintain carbon content and related fertility. Terra preta promises to end this ten thousand year struggle forever.

Every subsistence farmer now has the option of either burning all his plant waste out in the open field as he has done forever, or building an earthen kiln and producing a few tons of Biochar as fertilizer for next year’s crop. He does not need a dime from his government to do this nor does he need any special equipment that he does not already have. He had no other choice before and has been the source of monster smoke clouds out of Asia’s rainforests. Now those smoke clouds can become a fraction of what they are today while he mops up the carbon for us and strengthens his farms fertility.