(translated by Sean R. Stevens)
Yet another problem arises from intensive nitrogen fertilization: nitrous oxide (N2O, better known as laughing gas) is produced by the conversion of nitrates. Nitrous oxide is an atmospheric gas with a approximately 300 times higher global warming effect than carbon dioxide, the latter being generally blamed as the number one of climate damaging gases. Calculations made by the Nobel Prize winning scientist Paul Crutzen, awarded for his work on the ozone problem, point out that in comparison with the burning of fossil fuels, rape-seed diesel carries 1.7 times the effect on global warming, corn alcohol 1.5 times the effect, and wheat alcohol 1.3 – 2 times the effect. And that’s 
not all: nitrous oxide is within the class of ozone layer deteriorating nitrogen oxides. In this context, sugar cane looks a bit better, due to the fact that the ground in the countries where it grows – mainly South America – does need to be fertilized as intensively yet. But it should not be forgotten that the land needed to grow sugar cane in these regions is acquired by the slashing and burning of the rainforest, an activity that emits a great amount of carbon dioxide and further reduces the world’s plant resources, thus reducing the capacity for carbon dioxide removal.
One thing should not be forgotten in the discussion over bio-ethanol: We are trading food for fuel! There is already a noticeable increase in the price of grains in Europe, which unquestionably is a direct result of the lucrative use of grains as fuel additives. The consequence raising great ethical concerns is that aid to needing countries by giving away food, stemming from overproduction in Euope or the US, is weighted against the profit that can be made by converting it to fuel. Moreover, producers in food needing countries might favor the production of biofuels due to its higher market value. Even today, many people go hungry all over the world, and, with current trends, the world’s population is set to at least double within the next 50 years. Energy politics that promote the use of renewable fuels on large scale, especially from food resources could create a humanitarian catastrophe.
From my point of view, the use of bio fuel can only possibly represent a short lived contribution to the world’s energy supply, as the present and most definitely future energy needs are simply too great. Due to the described problem of trading food for fuel, I believe that prospective energy politics based on current technologies are very questionable. Further developments aiming at a more efficient usage of renewable resources will therefore be a very important challenge. The foundation of the new consortium Custom-made fuel from Bio-mass by the RWTH Aachen, which researches the use of renewable resources such as cellulose and lignin, plant components that cannot be used in food production, is a noteworthy step in the right direction. In contrast to the starches contained in the fruits of plants, amylose and amylopectin, cellulose, the main component in wood, is considerably more stable and cannot be easily transformed into ethanol through enzymatic processes, and is thus more difficult to break-down. The development of new chemical processes is being called for here, as this transformation should definitely be possible. Termites, for example, could possibly lead to clues.
The solution to the current energy problem must in the long run rely on other technologies, above all in the sustainable development of nuclear fusion and solar energy in combination with the photochemical splitting of water into hydrogen and oxygen. Further emphasis could then be given to the use of renewable resources rather than oil in the production of ethylene – and therefore of plastics – and other fine chemicals, one of the priority research areas in Chemistry at the Universit of Regensburg.
As a result of the enormous and consistent growth of the world’s energy requirement, and in the absence of real alternatives to the use of fossil fuels, atmospheric carbon dioxide concentration will considerable and inexorably increase in future decades, even in consideration of any possible decreasing endeavours involving of biofuels. The latter measures could slow down the increase of carbon dioxide concentration to 500-800 ppm, but not stop it. Life on this world will have to adjust to these changing conditions, with all disadvantages but also advantages that global warming will bring. How big the temperature change will actually be is unclear and highly controversial. From a chemical point of view, it is in no way clear that global warming will be brought about due to a further increase of carbon dioxide concentration,at least not to the extent outlined in many climate scenarios. Sadly, the discussion over the climate is based too much on descriptive circumstances, such as weather records, without addressing the chemical and physical fundamentals of the greenhouse effect.
Pictures
Corn (by Johann Jaritz; Wikimedia Commons)
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