Dr. José Goldemberg earned his Ph.D. in Physical Sciences in 1954 from the University de São Paulo in 1954 of which he became Rector in 1986. He has served as the President of Brazilian Association for the Advancement of Science, Minister of State for Education of Brazil and Secretary for the Environment of the State of São Paulo. He has authored many technical papers and books on Nuclear Physics, Sustainable Development and Energy.
“Environmental and Ecological Dimensions of Biofuels” – Keynote Address”
Prof. Jose Goldemberg
University of São Paulo; São Paulo,
In order to discuss the environmental and social dimensions of biofuels it is useful to compare two very large areas of activities of our present civilization: agriculture (i.e. food production) and energy. Agricultural production is based on the use of 1.4 billion hectares of surface land and generates approximately an average of 1 tonne of food per year per inhabitant. Energy comes mostly from fossil fuels and relies on underground deposits of coal, oil and gas; present average consumption is 1.6 tonnes of oil equivalent per capita. Oil represents one third of that, mostly used for transportation.
About half the world’s oil production is consumed by road vehicles. The fleet’s annual increase is about 10 million automobiles (doubling every 20 years or so) and 5 million buses and trucks worldwide. If the trend continues, more than a billion vehicles will be in the world’s roads by 2030. Not only is the number of automobiles and trucks growing but there is also a tendency to drive more, so the number of vehicles-miles traveled is increasing rapidly in countries such as the US. Also, vehicles tend to stay more time in traffic jams, consuming more energy per distance traveled.
Transport systems can adversely affect the environment in a variety of ways, such as disfiguring the landscape, but the most pervasive impacts arise from their exhaust gas and particulate emissions. One can attribute to transportation:
More than 70 per cent of all carbon monoxide (CO) emissions;
More than 40 per cent of nitrogen oxides (NOx) emissions;
Almost 50 per cent of total hydrocarbons (HCs);
Around 80 per cent of all benzene emissions; and
At least 50 per cent of atmospheric lead emissions 14% of all greenhouse gas emissions to the atmosphere and 19% of the CO2
Roughly speaking human beings consume on the average approximately the same amount by weight of agricultural products and energy “per capita” although there are enormous inequities in the distribution of food and energy among countries and between the rich and the poor. There is really – in physical terms – no lack of food or energy today in the world but access is another matter and approximately one third of mankind lacks both. The other two thirds, particularly in the OECD countries, have reached a level of access and satisfaction without precedent in industry.
Why can’t such a system work forever? For a simple reason: agricultural production is renewable and has been going on for hundred centuries; with suitable correction of soil and water access it can be maintained forever. Oil reserves as a fossil fuel are finite and presumably will not last many more decades.
No wonder, therefore, attempts have been made to use agricultural products as an energy source. Since remote antiquity wood has been used as a source of energy for cooking and heating and still represents today some 10% of all energy consumption, particularly in Africa where it is used with low efficiency. The problem today is in transportation, for which liquid fuels are needed.
Biofuels include ethanol produced from sugars and starch by fermentation with yeasts. Ethanol can be used pure or as a gasoline extender in spark-ignition engines. In addition, lignocellulose – from energy forestry, agricultural and forest industry residues, and the carbohydrate fraction of municipal solid waste (MSW) – is a further source of biomass liquids. Such a resource is 20 times more plentiful in the US than maize, and does not compete with food production. Since agricultural products grow in many areas of the world they are a solution to the problem of access, in addition of being renewable. A number of plant-derived oils have also been considered for possible use as fuels in diesel engines, including sunflower, soya, groundnut, cottonseed, rapeseed, palm oil and castor oil.
However they might pose environmental and social problems depending on the scale of production involved.
In 2006 the ethanol production of 34 billion liters (from sugarcane in Brazil and from corn in the US) replaced 3% of the world’s gasoline use of 1,2 trillion litters. The land requirements for the production of such amount was 3 million hectares in Brazil (5% of total agricultural area in case in Brazil) and a similar fraction in the US. It is clear therefore that concerns on “fuel versus food” competition are presently blown out proportion, certainly in Brazil. In the US the situation is more complex because there is a direct competition between corn and soy which resulted in price increases of corn.
Concerns on the sustainability of biofuels production are being widely discussed which is somewhat unexpected because such questions were not asked in the past when the oil era started. Today 30 billion barrels of oil are being burned per year. Biofuels production today is 300 million barrels equivalent per year which is the production of a modest oil field. Such production requires 6 million hectares of land and generates 2 million direct jobs. In the petrochemical industry – for the equivalent production of oil – only 10,000 jobs are generated.
To generate one job in ethanol production one requires an investment of 11,000 US dollars. The petrochemical industry requires 220,000 US dollars per job.
This does not mean that a large expansion of biofuels production – which is contemplated in a few countries particularly the US and Brazil – will not exacerbate environmental and ecological problems. To avoid or minimize them a large effort is being conducted to introduce sustainability criteria in the production of biofuels approximately along the lines of sustainable forest development. The present “status” of the efforts to introduce such criteria will be discussed.