Reduction of greenhouse gas emissions: Contribution of Bangladesh
Since the advent of the industrial revolution in the 1700s, humans have devised many inventions that burn fossil fuels. Burning these fossil fuels, as well as other activities such as clearing land for agriculture, or urban settlements, releases some of the gases that trap heat in the atmosphere. These atmospheric gases have risen to levels higher than at any time in the last 420,000 years. As these gases build up in the atmosphere, they trap more heat near the earth's surface, causing earth's climate to become warmer than it would naturally be. The heat-trapping gases in the atmosphere behave like the glass of a greenhouse. They let much of the sun's ray in, but keep most of that heat from directly escaping. Because of this, they are called greenhouse gases.
Scientists call this unusual heating effect as Global Warming and blame it for an increase in the earth's surface temperature of about 0.6O C (about 1O F) over the last 100 years. These warmer temperatures could melt parts of polar ice caps and most mountain glaciers, causing a rise in sea level up to 1 m (40 in) which would flood coastal regions including that of Bangladesh. Due to overwhelming scientific evidence and growing political interest, global warming is currently recognised as an important national and international issue. In 1997, representatives met in Kyoto, Japan, and produced an agreement, popularly known as the Kyoto Protocol, which requires industrialised countries to reduce their emissions by 2012 to an average of 5 percent below 1990 level as per Article 3.1 of the protocol.
To help countries meet this agreement cost effective, negotiators developed a system in which nations that have no obligations or that have successfully met their reduced emission obligations could profit by selling or trading their extra emission quotas to the countries that are struggling to reduce their emissions. Bangladesh, being one of the few countries having lowest level of carbon dioxide emission per capita which is only 0.16 tons as against 18.97 tons of USA, 10.68 tons of Germany and 9.49 tons of UK, can easily reduce further greenhouse gas emissions and trade additional reduced Emission Reduction Units (ERU) with the countries like USA, EU and others, as per the Article 6.1 of the Kyoto Protocol.Greenhouse gases
Greenhouses gases that have been identified and included in the Annex A of Kyoto protocol are Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydroflurocarbons (HFCs), Perfluorocarbons (PFCs) and Sulpher hexafluoride (SF6).
Carbon dioxide: dioxide constantly circulates in the environment through a variety of natural processes know as carbon cycle. Carbon dioxide is released to the atmosphere when solid waste, fossil fuels (oil, natural gas, and coal), and wood and wood products are burned. Humans cut down huge tracts of trees for lumber or to clear land for agricultural farming, industries or increasing human habitations. This process, is known as deforestation, significantly reduces number of trees available to absorb carbon dioxide.Methane:
Methane is emitted during the production and transport of coal, natural gas, oil, decomposition of organic wastes in municipal solid waste landfills and anaerobic conditions associated with rice paddy field. Atmospheric concentrations of methane are far less than carbon dioxide, and methane only stays in the atmosphere for a decade or so. But methane is an extremely heat trapping gas -- one molecule of methane is 20 times more efficient at trapping infrared radiation from the earth's surface than a molecule of carbon dioxide. Rice based agriculture plays a very important role in the global inventory of methane gas. Worldwide, irrigated rice cultivation is considered to be among the highest sources of atmospheric methane and nitrous oxide under certain water management regimes.Nitrous oxide:
Nitrous oxide is emitted during agricultural activities such as cultivated soil, using of nitrogen-based fertilizers, industrial activities, disposing of human and animal waste and automobile exhausts. Nitrous oxide is powerful greenhouse gas, about 310 times more effective at trapping heat than carbon dioxide on a molecule-for-molecule basis.
Fluorocarbons:
Fluorocarbons are rarely occurring in nature. It is manufactured by humans for refrigeration, aerosol spray, propellants and cleaning solvents. Fluorocarbons are the strongest greenhouse gas per molecule. It is thousand times more effective in trapping heat than a single molecule of carbon dioxide.Greenhouse gas emissions from rice-based agriculture: Over half of the total rice paddy area is concentrated in India (44.5 million ha) and China (28.58 million ha). Bangladesh is the third largest country where rice is cultivated in10.9 million ha, which is 75.35% of total cultivated land of the country. Rice is the world's single most important feed crop and the primary food for more than a third of the world's population and makes up over 30% of the food consumption for the third world, almost twice that of wheat, the next largest food source. It is significant that most of the world's population growth is in the rice growing countries. Paddy rice corresponds to approximately 10% of the global cultivated agricultural area, constitutes approximately 20% to the global natural freshwater wetland area, and is estimated to contribute between 10% and 20% of the total annual emission of methane to the atmosphere.
To meet the rice supply of growing populations, rice cultivation will continue to increase at or beyond its current rate. In fact, arable land is highly limited in major rice growing areas; increased production has to be achieved mainly by intensifying cropping (i.e. two or three crops per year) rather than expanding the area of rice cultivation.
When rice fields are flooded, methane (CH4) production is highest and nitrous oxide (N2O) emission is lowest. During times when rice fields are drained, as a management practice or drought during the growing season, at harvest time, during fallow periods, during cropping season of upland crops in an annual cropping sequence, and during land preparation for planting rice, methane (CH4) production is probably low and net consumption may exist and nitrous oxide (N2O) emissions is high.The use of nitrogen-based fertilizers, macro and micronutrients from chemical fertilizer sources are essential to agricultural production and in raising productivity, but surplus of nutrients in excess of crop needs, which is a common practice in Bangladesh, can lead to nutrient emission of nitrous oxide. This emission can potentially be a source of environmental damage to water and air quality, and contribute to global warming. Bangladeshi farmers use fertilizers efficiently when crop prices are low and fertilizer prices are high.
According to the Intergovernmental Panel on Climate Change (IPCC), if fertilizer applications are doubled, emissions of nitrous oxide (N2O) will also be doubled, all other factors being equal. Therefore, judicial and efficient use of nitrogen fertilizers shall be one of the few options to reduce N2O emission from agricultural farmland.
It is essential that total nitrogen use in rice-paddy cultivation is reduced without sacrificing yield of rice paddy. Nutrient enriched organic fertilizers used under Integrated Plant Nutrition System (IPNS) can effectively reduce excess use of nitrogen fertilizers like urea and other chemical fertilizers like TSP, MOP etc. by almost 10%-40% resulting in reduction in nitrous oxide emission by 10%-40% without sacrificing any crop yield. Use of nutrient enriched organic fertilizer always increases crop yield, produces high quality seeds, increases income of farmers and maintains long term soil fertility.Emission trading
Emission trading is emerging as a key instrument in the drive to reduce greenhouse gas emissions. The rationale behind emission trading is to ensure that the emission reductions take place where cost of the reduction is lowest thus lowering the overall costs of combating climate change. Emission trading is particularly suited to the emissions of greenhouse gases, the gases responsible for global warming, which have the same effect wherever they are emitted. This allows the government to regulate the amount of emissions produced in aggregate by setting the overall cap for the scheme but gives companies the flexibility of determining how and where the emission reductions will be achieved. By allowing participants the flexibility to trade allowances the overall emission reductions are achieved in the most cost-effective way possible.
A metric measure is used to compare the emissions from various greenhouse gases based upon their global warming potential (GWP). Carbon dioxide equivalents are commonly expressed as "million metric tons of carbon dioxide equivalents (MMTCDE)".
The World Bank estimates that some 67 million tons greenhouse gas emissions were traded in 2002 and that carbon trading should become a multi-billion dollar market within a few years. GHG emissions could eventually become the world's largest commodity market -- one that is deep and liquid, with secondary and derivative markets. The United Nations Environmental Programme (UNEP) estimates that the market will reach USD 2 trillion by 2012.Conclusion
Nitrous oxide is a powerful greenhouse gas, about 310 times more effective at trapping heat than carbon dioxide on a molecule-for-molecule basis. It is regularly emitting from our rice based cultivation process. Since rice is the staple food of the general population of Bangladesh, neither its crop yield could be sacrificed nor could its pattern be changed to avoid nitrous oxide emission. But reduction of this dangerous gas emission could easily be done (30%-40%) by strongly practicing IPNS technology that includes use of nutrient enriched organic fertilizers and sell these emission reduction units as per the Article 6.1 of the Kyoto Protocol.
Bangladesh can earn millions of dollars every year by selling 800,000 tons of carbon dioxide equivalent greenhouse gas emissions from rice based agricultural farmland alone (Source: The Daily Star, 12 August, 2005)Top of page
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