Global warming - agriculture - biotechnology

Carbon cycle is an important process constituting global ecology. In the last year it became also very popular problem and political and economical issue in connection with sc. global warming.

Carbon is present in nature in various forms from totally reduced methane (CH4) to totally oxidised carbon dioxide (CO2). In living matter its state is roughly intermediate. The central process that brings carbon from CO2 in more reduced state of living matter is photosynthesis. The opposite process is aerobic respiration.

Not all living matter is rapidly oxidised by respiration up to CO2 and is accumulated in long-lived organic form like humus or coal. Huge amount of CO2 is dissolved in water depending on its acidity and temperature. These basic processes modulate the concentration of CO2 in the atmosphere - the part that enters the social and political sphere as it absorb infrared radiation coming from the Sun preventing it from escaping again out to the extraterrestrial space. This is the root of global warming.
It was accepter by many scientists and policymakers that mankind oxidising the long-term deposits of reduced carbon like coal, oil and natural gas shifts the balance between reduced and oxidised form of carbon. Resulting rise of CO2 concentration in the atmosphere keeps more infrared radiation and blamed to cause the global warming.
However, the global warming case is not as simple as it is presented in popular presentations.

First, there are more gases in the atmosphere that absorb infrared. Most abundant is the water vapour. Methane is 20-times, N2O roughly 300-times more effective than CO2 (see table) and ozone and freons are even more effective. The participation on warming is very different. In humid warm regions water plays the dominant role. In could and dry climate without human participation main contribution comes from CO2

In standard popular articles industry and transportation is blamed as chief human activities escalating the greenhouse effect. Consequently they are most appealing political targets. Agriculture is left behind what is far from reality. Agriculture starts by liquidation of existing natural habitant - forest or prairie - and preparation of the soil by tilling follows. This generates large evolution of CO2 and generally reduces the carbon log-lived deposit of humus. Wetting of dry soil by irrigation results in humus oxidation as well. Tilling and irrigation are stable factors in agriculture. The fate of carbon is variable. Crops photosynthesis removes it from the air but final uses of the harvest release it back in different way.
Manuring by nitrogen containing substances - either stable mist or industrial - leads to the evolution of N2O. Agriculture releases more than half of this gas globally. Even higher is the emission of methane estimated on >80% of global emission. Cattle and flooded fields of rice as other wetlands are large sources of CH4.
Application of biotechnology can reduce the participation of agriculture in greenhouse gases production. The herbicide-tolerant (HT) crops allow minimize tilling to practically zero. They save both - humus and fuel. Transgenic cultivars of rice are developed to avoid flooding of fields reducing the methane production. Crop varieties with improved efficiency of nitrogen utilisation were developed by genetic modification and are prepared in laboratories. Such varieties reduce the fraction of nitrogen released as N2O.
However, the biotechnology role is not limited to these direct contributions. There is considerable political pressure on agriculture to provide "alternative sources of energy", particularly fuel. The situation in this respect is a mixture of several interests. The import of bioethanol from Brazil to Europe is clear nonsense from the ecology point of view. But it reduces the dependence of EU on oil suppliers. The subsidiaries for growing rape seed for diesel fuel is nonsense in both respects and in addition contributes to the greenhouse gases by the emission of volatile methylhalogenides. But it is welcomed by farmers and industry producing biodiesel.
Biotechnology can develop plants growing on lower quality of soils with limited or zero need in fertilizers and pesticides. Transgenic poplars are introduced in China on large scale. Transgenic eucalypt grows on soil with high salt content. Programmes of developing spruce resistant to bark beetle are in progress.
The other field for biotechnology is open in processing the wastes from agriculture. Large quantity of biomass is left after the production of edible oil from rape seed or sunflower. There is more wheat straw than can be used in animal production. Wood industry produces considerable mass of wastes. This lingo-cellulose complex can be transformed into energy with CO2 production equal to amount consumed in photosynthesis. But the technology of realistic economy should be developed.
Unfortunately the EU programme in biotechnology is far from optimal. Several Member States are keeping the anti-biotechnology position developed in times of food crops overproduction. The fear from transgenosis implanted in thinking of Europeans survives. However the world including Asia and Africa is moving ahead and Europe will be pushed to follow.