Running a car with fuel that has grown on the fields sounds like a safe and attractive option for a climate-conscious citizen. The plants grown for biofuel production absorb CO2 from the atmosphere and combustion of the biofuel releases only the CO2 previously absorbed by the plant. Therefore biofuels typically have far lower well-to-wheel GHG emissions than fossil fuels. With the surge in fossil fuel prices in the recent past and government programmes supporting the production of biofuels, the demand for plant-based energy has risen sharply. In the United States for example, the US Renewable Fuels Standard (RFS) required in 2006 that 1 500 million litres of the US fuel supply be provided by renewable fuels, and it is supposed to increase to 28 400 million litres in 2012.
With a further surge in demand ahead of us it is worth looking at ways to ensure a sustainable production of energy corps. Whether biofuels are "good" or "bad" is a matter of introducing a number of environmental and social safeguards.
Bioenergy - the use of biomass - has been and in many regions still is one of the most prominent sources of energy, in developing countries often enough inefficiently. Bioenergy refers to biomass converted to higher value and more efficient and convenient energy carriers, such as pellets, gas, or liquids. Most common liquid biofuels used for transportation are ethanol and biodiesel.
Bioethanol is an alcohol that can be made from almost any crop that has a high content of sugar (sugarcane or sugar beet), starch crops (corn) or any cel-lulosic crops. The alcohol is mainly produced through a repetitive fermentation process which involves soaking, crushing or chemical extraction using a process similar to that used in
beer and wine-making. Ethanol can run in an ordinary petrol car engine without modifications up to a 10 per cent blend level (some manufacturers warrant 5 per cent only, some warrant up to 15 per cent). In Brazil, where about 40 per cent of all fuel used is produced from sugar cane, all cars operate with engines slightly modified to run on blends up to 25 per cent ethanol. A car engine can be further modified (in its design and configuration) to be "flex fuel", that is to operate on fuel blends of anywhere from 0 up to 85 per cent ethanol.
Biodiesel is produced from oil, which can be sourced from oil seed crops such as rapeseed, soy bean, sunflower or jatropha and from waste oil such as cooking oil. Water and other contaminants are removed from the oil and the fatty acid content present in the oil is separated and transformed. Biodiesel can be blended with conventional diesel in vehicles, usually in a 5 per cent blend (B5).In some countries it is sold in blends up to 20 per cent (B20) or in pure form (B100) that some specially modified diesel vehicles can handle.
The technologies to produce fuels from waste from agriculture and forestry, or specific plants with high cellulose content are still a few years away from competitive commercialization. The industry assumes that second-generation biofuels will not be available in significant commercial quantities for five to 10 years. The advantages put forward are high energy efficiency, and the use of plants that grow on degraded land or in areas less important for biodiversity.
How efficient are biofuels in reducing GHGs?
In order to utilize the full potential of biofuels for reducing GHG emissions it is crucial that the total of emissions created during their production are both as low as possible and below that of their fossil alternative. There are many elements that can lead to higher greenhouse gas emissions from biofuels than in the optimal case: GHG emissions are mainly due to fossil fuel inputs into cultivation and downstream processing. But the final result also depends on the type of crops and finally the efficiency of the engine running on it. The International Energy Agency says about 15-25 per cent reduction in GHG emissions compared to fossil fuels can be achieved by using starch based crops, for example corn in the United States, but a 90 per cent reduction with sugar cane as feedstock as grown in Brasil. In some cases the climate balance of biofuels is even negative. Nitrous oxide emissions from fertilizer application during the cultivation of the plants partially reduces CO2 emissions savings.
Although growing fuel in fields sounds highly promising for solving our energy and climate problems, there are a number of controversial issues around biofuel production.
Energy versus Food: Sceptics are concerned that where biofuels are grown, no food will be harvested, and some even call for a moratorium. In a world where 850 million are considered undernourished any potential threat to aggravate this situation requires thorough and critical examination. Over the past three years, global food prices have risen 83 per cent. Governmental subsidies and targets for biofuel in developed countries has created a sudden increase in demand, partly responsible for the rise. Among a number of other factors are population growth and changing diets towards more energy intensive meat consumption. Energy crops may compete for land with other uses and potentially result in increased food prices. For some types of bioenergy crops marginal and waste lands are suitable. This is the case, for example, for grasses and jatropha. However, the best yields and profits arise from using good quality land, and this also applies for energy crops.
It is recognized that crop yields in much of the world are below their potential, and improved management practices could increase yields substantially, which would allow to accommodate both food and energy crops. Of the 13 200 million hectares of the world's total land area, 1 500 million hectares are used to produce arable crops and 3 500 million hectares are in pasture for meat, milk and wool production. Crops used specifically for biofuels occupy currently 25 million hectares. Many of the poor suffering from increased food prices suffer as well from increased oil prices, and local biofuel production for local use can provide substantial benefits by spurring other economic activities that would allow to raise income.
Fields versus Forests: Another threat is that the rising demand for energy crops puts pressure on forests, wetlands and other areas of high carbon stock value to win arable land, as happened in the past for soy beans or palm oil. This could cause much higher GHG emissions from released soil carbon and cleared biomass than is fixed by the cultivation of the respective crops.
Mobility versus Sustainability: Yet another concern is the way energy crops are grown. As with other intensive agricultural practices, in the absence of strictly controlled prerequisites for sustainable production, energy crop farming contributes GHG emissions from soil exploitation and the application of fertilizers. It will also increase pressure on already scarce freshwater supplies. Monocultures reduce biological diversity, decrease soil fertility and are vulnerable to pests.
In order to make biofuels a successful tool for mitigating climate change without compromising people's livelihoods, rules for the game have to be developed. Environmental organisations, concerned countries and leading international organizations are demanding an internationally agreed certification scheme for the production of biofuels that addresses concerns related to climate change, biodiversity, water and soil as well as labour conditions, indigenous people's rights, land rights and food security. The "UN energy report" warns: "Unless new policies are enacted to protect threatened lands, secure socially acceptable land use, and steer bioenergy development in a sustainable direction overall, the environmental and social damage could in some cases outweigh the benefits". Governments as well as the private sector need to take coordinated action to ensure sustainable production and use of biofuels, so that they may play a useful role in the transformation of the energy sector. Internationally agreed sustainability principles and criteria; identification, designation and monitoring of "no go areas" with regard to carbon storage and biodiversity potentials; social safeguards that ensure that vulnerable people are not disadvantaged through food and energy price increases, and access to modern forms of energy are among the elements taken into account by UNEP as they are collaborating with others on the development of criteria to maximize development benefits of bioenergy.
In green: virtuous initial equation in favour of biofuels
Biofuel versus fossil fuel
In red: main concerns related to biofuels
In blue: main concerns related to fossil fuels
Agricultural prices up
Agricultural prices up
FAMINE, MALNUTRITION and other HEALTH CONCERNS
FAMINE, MALNUTRITION and other HEALTH CONCERNS
Land use competition with food production
Global process: » Agricultural production* Massive need for agricultural land
Deforestation Land use change
Water and soil
Production and use of fertilizers------------> pollution "
Fossil fuel shortage
Prospecting « and extracting
1 Industrial transformation process -» Distribution-------------
Greenhouse gas emission t
Final use (road transport)
Petrol and diesel substitution
Greenhouse gas emission
Fossil fuel burning (petrol and diesel use)
Final use (road transport)
* Under the high productivity farming conditions that are prevailing today.
Source: Emmanuelle Bournay, Atlas Environnement du Monde Diplomatique 2007.
Multinationals have the opportunity to choose where to base their operations for the most profitable return. So they can decide - or not - to minimize their impact by locating production close to the point of consumption. They can also choose to ensure that their production and distribution facilities are climate-neutral. So the oil giant Shell, for example, can claim it is trying to minimize emissions from exploration, oil and gas production, shipping and refineries: "Our customers emit six to seven times more CO2 using our products than we do making them. A small share of the energy products we make, such as electricity from our wind turbines, emit no CO2 at all during use."
The US Pew Centre for Global Climate Change (www.pewclimate.org) reports on progress made by Deutsche Telekom, a member of its Business Environmental Leadership Council. The company's vehicle fleet's CO2 emissions have fallen about 30 per cent from their level six years ago, thanks to the use of smaller or alternative-fuel vehicles, choosing trains instead of car or plane travel, using videoconferencing instead of travelling at all, and incorporating environmental impacts into the company's technical specifications for vehicle suppliers and manufacturers.
Corporations exert significant influence over the lives of their employees, to the extent of telling them when they have to arrive at work and leave. Staggering working hours would cut congestion and perhaps lead to an even more radical idea - telling staff to work from home. Cutting commuting would help the planet, as well as the ex-commuters' nerves.
Businesses can develop mobility plans for employees, organize car fleets, and provide incentives for using public transport for commuting to work. They can subsidize cyclists (and even simply provide proper changing and shower rooms for them at work), and buy bicycles or electrobikes. They can also draw up and apply strict rules for duty travel, requiring the use of trains for all journeys below a specified distance.
Cities can make a significant contribution on their own account to reducing GHG emissions from transport. In fact, the same suggestions apply to cities as to businesses.
City governments can also play a key role by making low-emission transport more attractive to their citizens. Designing streets that are friendlier to pedestrians and cyclists than they are to four-wheeled vehicles will encourage more people to leave their cars at home. Integrating public transport into a seamless system which enables passengers to switch effortlessly from bus to tram or train or metro will attract more users. Some cities have introduced congestion charging systems, requiring drivers in the central area to pay a fee: they include Singapore, Stockholm, Oslo, Milan and London.
Spatial planning is an important civic function which can help significantly to cut energy use in urban transport. Cities can retain their focus and sense of place if they plan for "densification" as opposed to Los Angelesstyle sprawl. By avoiding "sleeping cities" and planning mixed functions in neighbourhoods, commuting can be minimized. This can save GHG emissions, because energy consumption in cities is directly linked to the number of inhabitants per square kilometre.
Abu Dhabi, in the United Arab Emirates, is planning a new city, to be called Masdar, which will rely entirely on solar energy, with a sustainable, zero-carbon, zero-waste ecology. It will cover six square kilometres and house energy, science and technology communities. Masdar has been planned as a high-density city, with electric-powered vehicles providing public transport. The designers, the British architectural firm Foster and Partners, say: "Rooted in a zero carbon ambition, the city itself is car-free. With a maximum distance of 200 metres to the nearest transport link and amenities, the compact network of streets encourages walking and is complemented by a personalized rapid transport system. The shaded walkways and narrow streets will create a pedestrian-friendly environment in the context of Abu Dhabi's extreme climate. It also articulates the tightly planned, compact nature of traditional walled cities."
A Chinese city, Dongtan, hopes to be the world's first sustainable city, with all the buildings powered by renewable energy, and self-sufficient in water
Transport-related energy consumption Gigajoules per capita per year
• Los Angeles San Francisco Boston
-Perth —Brisbane Melbourne Sydney
Hamburg Stockholm , Frankfurt Zurich / Brussels Munich -West Berlin Copenhagen Vienna
Was this article helpful?