Energy is most vital for all human beings. It is an essential resource for our socio-economic development. The energy we consume is mostly in the industrial, transport and domestic sectors. At present, more than 90 per cent of it is derived from fossil fuels. The transport sector assumes great importance not only for human beings but also various commodities and animals. It is expanding very fast with the increase in population, industrialisation and various socio-economic activities.
Nearly 90 per cent of the fossil fuels are being used to provide energy for land, water and air transport systems. Energy consumption in the transport sector is around 26 per cent of the total energy consumed in the world. In 2010, energy consumption in the transport systems was dominated by road transport amounting to 76 per cent, followed by aviation and sea transportation 11 per cent each and the rest for others.
During the last two decades or so, oil consumption in the world in road transportation has grown to 70 EJ (70 x 1018 J). While the use of bio-fuel has increased sixfold with 2.4 EJ. However, it accounted for only 3.34 per cent of the road transport energy consumption. The natural gas consumption for road transport between 2000 and 2010 has increased sevenfold to a value of 0.9 EJ in 2010. Unfortunately, electricity consumption in the road transport sector rather declined during this period.
Although the transport sector helps considerably in our socio-economic development, it has been one of the major culprits in polluting our environment due to the release of Greenhouse Gases (GHG), mainly carbon dioxide, nitrous oxide etc. Since mostly fossil fuels are used, this sector now accounts for about 23% (7.3 x109 T) of annual global energy-related CO2 emission (32 GT), whereas in 1970 the CO2 emission was less than half of the present figure (3.3 GT per year).
The atmospheric concentration of GHG has been increasing at a fast rate mainly due to the burning of huge amounts of fossil fuels in industries, transport and other sectors. These GHG are responsible for causing global warming. Since the industrial revolution (1760- 1820) to date, the global temperature has gone up by 0.80 C and even more in sensitive polar regions. Now, the effect of global warming is appearing all over the globe in some form or other. During the last 100 years, mountain glaciers and snow cover have decreased significantly in both the northern and southern hemispheres. Such widespread decrease in glaciers and ice caps has contributed to a significant rise in the sea level, resulting in the inundation of many low-lying landscapes.
Decreasing glaciers and snow covers are likely to reduce the availability of freshwater. Arctic snow may vanish within 10 years as it is melting much faster than previously believed. The disappearance of glaciers and ice caps may increase volcanic eruptions.
Climate change has already affected agricultural patterns and food production; warmer summers favour the appearance of various diseases, the spreading of insects and the scarcity of fresh water and thus considerably affect our living conditions. For example, in 2004, climate change has been responsible for an increase of about 3 per cent of each of diarrhoea and malaria and 3.8 per cent of dengue fever deaths worldwide. Climate change is not only affecting health but also the socio-economic conditions of people in different parts of the globe. The most affected countries would be those with agriculture-led economies.
In view of all this, it is essential to replace fossil fuels with renewable energy in the transport sector as much as possible. Globally, about 93 per cent of the transport sector is driven by petroleum-based fuels, 2 per cent by bio-fuel and natural gas contributing only 1 per cent.
The International Energy Agency (IEA) has expressed great concern about GHG emissions due to the use of fossil fuels in the transport sector. The agency has suggested using an increasing amount of renewable energy in this sector. The following three policies as suggested by IEA have to be implemented sincerely as early as possible.
- Implementation of the committed strategies by different countries should be carried out in due periods to cut down the amount of GHG. For example, in 1992 USA planned to replace 10 per cent of petroleum-based fuels by 2000 and 30 per cent of that by 2010 by using environment-friendly fuels, whereas, by 2013, oil replacement was only 8 per cent. Similarly, in 2003 in India the target was to replace 20 per cent of fossil fuel with biofuels (biodiesel or bioethanol) by 2017. But this could not be achieved even up to 5 per cent due to insufficient production of biodiesel. Its production target could not be achieved due to the unavailability of sufficient feedstock and pricing issues. Similarly, in Germany to achieve electric vehicles (EV) share of 20 per cent in the transport system by 2020 could not even reach 1 per cent by 2014.
- Additional policies should be implemented to increase the diversification of transport energy needs. IEA feels that to achieve GHG reduction substantially, the sale of electric vehicles, which is now only less than 1 per cent of the total sale of vehicles, should go up to 40 per cent by 2040. By that time, bio-fuel to be used in road transport should be 10 per cent, and those for shipping and aviation should be 11 per cent and 33 per cent respectively. Natural gas being a carbon-based fuel, cannot be that effective to cut down GHG emissions.
It is interesting to note that globally, the sale of electric bikes and scooters dominate that of electric cars by a wide margin (350 e-bikes or scooters are sold for every 1 electric car). For example, in 2013 about 112,000 electric cars and 40 million electric bikes and scooters were sold worldwide. It is reported that in China, there are more electric bikes and scooters than the total number of cars on road. In 2013, the sale of electric bikes and scooters in China was 32 million, in Europe 1.8 million, in Japan 440,000 and in the USA only 185,000.
It may be mentioned here that Brazil is the pioneer in replacing petroleum-based fuels with renewable energy in the transport sector. For example, in 2004, IEA predicted that by 2020, Brazil can replace petroleum-based fuels with alternate fuel by 27 per cent. Over 85 per cent of all light-duty vehicles in Brazil use Flax Fud Technology (i.e., a combination of gasoline with ethanol) and it is predicted that, by 2020, 80 per cent automobile fleet will run with ethanol.
- IEA has suggested making policies favouring the use of renewable energy in place of fossil fuels, by removing various incentives given at present for use of fossil fuels. Further, the loss due to pollution should be taken into consideration. All emissions associated with fossil fuels production, distribution and combustion should be taken care of by concerned industries otherwise they should be charged appropriate ‘Polluter’s fee’.
Increasing the application of electrical energy in the transport sector is one of the most important steps towards renewable energy provided electrical energy is produced from renewable sources. In this case, GHG released from fossil fuel-based energy can be minimised considerably. Countries like Costa Rica, Colombia or Brazil those have hydropower will have relatively clean electricity while countries with coal-based electricity generation will produce electricity with high GHG emission.
In view of the harmful effects of global warming on this planet, particularly on human beings, it is advisable to use all sources of renewable energy in the transport sector in the years to come. IEA estimates that if sincere efforts are made all over the world, renewable energy could become the leading source of electricity by 2030 and the carbon intensity of the power sector is projected to improve by 30 per cent during that period. Cooperation of all the nations in this regard for the benefit of humanity is highly desirable.