Global Warming
Why must the poor suffer for the fault of the rich?
Global warming refers to a rise in the average land temperature around the earth. The Intergovernmental Panel on Climate Change (IPCC) concludes, "most of the observed increase in globally averaged temperatures since the mid 20th century is very likely due to the observed increase in anthropogenic green house gas concentration" which leads to warming of the surface and lower atmosphere by increasing the green house effect. IPCC predicts that global temperatures are likely to increase by 1.1 to 6.4ºC (2.0 to 11.5ºF) between 1990-2100. In recent past, global observations have provided clear evidence of climatic changes resulting from anthropogenic activities. According to a report from World Watch Institute (1992), the earth's surface was the warmest in 1990. Six of the seven warmest years on record have occurred since 1980. Global warming may have brought severe consequences for Bangladesh with the rise in sea level by up to one meter by the turn of the next century and, as is being predicted, between 10-17 percent of our total land mass will be submerged. More than ten million people will be worst sufferer. Forest agriculture, infrastructures, coastal aquaculture and flora and fauna would be severely damaged. Among the other predicted consequences of global warming are a rise in the frequency and intensity of tropical cyclones, increase in flooding severity and greater desertification in our northern districts. Now the question arises naturally in our mind regarding the causes and impact on environment irrespective of the countries of the world and possible solutions to be identified to curb this burning problem. There are several green house gases responsible for rapid increased in temperature. These are found due to fossil fuels, industrialisation and agricultural processes caused by humans, and natural activities and other gas emissions. Carbon dioxide is the most common thought of as a green house gas directly involved in retaining about half of the atmospheric heat. Its production primarily depends on the burning of fossil fuels and deforestation accompanied by burning and biodegradations of biomass. As soon as the concentration of this gas increases in the earth, the temperature rises resulting in melting of ice causing flood and a dramatic rise in sea level. Roots of rice plants transport methane to the atmosphere. According to an estimate around 100 millions tonnes of methane are released annually. Methane (CH4) is 25 times more effective than CO2 in absorbing the outgoing infrared radiation. It produces in atmosphere carbon monoxide (CO) as an intermediate oxidation product influencing concentration of atmospheric hydroxide radicals and ozone. CFCs (Chloro Fluoro Carbons) do not occur naturally and are totally man made. This green house gas built up in the atmosphere traps heat. This is the major cause of global warming. Energy from the sun heats the earth surface and in turn heat energy is radiated back into space. Green house gases trap some of the outgoing energy to retain heat and thus heat the planet. If these natural process would not have happened the global temperature would remain lower than it is now. This heat trapping phenomenon is known as green house effect. With glaciers melting the world over and average temperatures becoming higher year on year global warming is well and truly upon us. The IPCC has recently concluded that this is primarily due to human activities. Developed nations are well equipped to face this type of disaster while developing nations fail to realise their bad infrastructure and poor disaster management practices which claim thousands of lives. The rate of global warming and sea level rise during this century could be devastating. Estimated land losses range from 0.05 percent for Uruguay to about 80 percent for the Majuro Atoll in Marshall islands. A 1m (3 feet) sea level rise would affect 6 million people in Egypt, with 12 percent to 15 percent of agricultural land lost; 13 million in Bangladesh, with 16 percent of national rice production lost, and 72 million in China. Global warming is at the root of this increase as the earth's climbing temperatures melt the arctic sea ice and Antarctica. Around the world, ice sheets and glaciers are melting at a rate unprecedented since record keeping began. Changes in the area and volume of two polar ice sheets in Antarctica and Greenland are intricately linked to changes in global climate and could result in sea level changes that would severely affect the densely populate coastal regions in earth. Three major impacts of global warming on Bangladesh may be categorised as climate change, sea level change and changes in the pattern of distribution and density of population. Global warming will raise the sea surface temperature more than what it is now, thus increasing the possibility of cyclone occurrences. Bangladesh has been experiencing catastrophic cyclones. A warmer climate by increasing the frequency of natural hazards as floods and cyclones will further aggravate such situations and negate the development efforts of the country. Some effective remedial measures need to be implemented as quickly as possible in order to reduce global warming and protect Bangladesh from further degradation due to emission of green house gas. The aims and objectives of the government should be to discourage deforestation and create mass awareness for a forestation in every part of the country. Emphasis must be given to crops which are most efficient in fixing carbon dioxide into bio-mass especially perennial tropical crops such as sugarcane and trees. Production of wetland rice in tropical countries may be discouraged in favour of dry land cereal production for human consumption. A massive programme is needed to promote strategies supplementation of ruminant diets in third world countries to optimise functions which lead to reduce methane and carbon dioxide production. Maximum support should be given to research and development efforts which will enable fossil derived fuels to be replaced by biomass derived fuels like biogas. High cost systems of food production and other high fossil fuel dependent activities in industrial countries should be discouraged and discontinued on an emergent basis. The international agencies and government and non-government organisations can play an important role in ensuring the adopted polices for reducing the evolved green house gases. On December 11, 1997 in Kyoto, Japan 150 nations agreed in principle to the plant urging thirty-eight industrial nations to must reduce their emissions of green house gases to an average of 5 percent below 1990 levels by 2012. Although the average cut must be to only 5 percent below 1990 levels, for a country like the United States with steadily rising emissions, the Kyoto agreement would require cuts as great as 30-35 percent below. China and India are asked to set voluntary limits. It is a matter of satisfaction to note that President Bush of USA has agreed in principle to hold a meeting with developed and developing countries to come to a consensus on the reduction of green house gases. So, it is expected there will be less possibility of increased temperature on the earth surface and the poor developing countries could get a relief from this impending danger and consequently these countries too would strictly follow the international laws with a view to safeguarding environment from pollution and degradation of sorts. Dr. Md Shahjahan Ali is professor, Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh.
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