Prof Dr R D Gupta
A report by Scientists from 23 countries found that warming of the earth due to “Global Warming” would reduce agricultural production in many developing countries, especially those belonging to the third world. The Scientists have found that production of wheat, rice, soybeans and maize would be more seriously damaged as temperature would rise. By the middle of the 21st Century there would be increase in atmospheric temperature to an extent of 1.5 to 4.0 degree Celsius if emissions of the gases that are trapping heat on the Earth are not curbed. At 4 degree Celsius level, production of cereals would be reduced to the order of 9 to 11 percent in the developing countries. However, in the developed countries farm production would generally increase if the Earth warms. This would happen for two reasons. Firstly the higher temperature would permit crops to be grown further north in the temperate zones and growing seasons would be lengthen. Secondly when warming would occur, the developed countries can take up large scale adaptive measures because of having much more resources to their credits for tackling such situation.
Elevated levels of atmospheric carbon dioxide have decidedly beneficial effect on crop production through an enhancement of photosynthetic capacity and an increase in water use efficiency. Arrhenius (1896), The first author for describing the concept of “Global Warming”, suggested its possibilities over 100 years ago. He favoured the view that slow warming without doubling of the Earth’s atmospheric CO2 would result in better living conditions and higher crop yields.
Concerning with the changes in levels of atmospheric carbon dioxide, there are some well known facts. First, there is a documented increase. The isolated Test site at Mauna Loa in Hawaii shows more than a 12 percent increase in the mean and really Concentration from 316 ppm (by volume of dry air) during 1959 which at present is 370 ppm (Gupta, 2005). The current annual rate of increase is about 1.6 ppm. Carbon dioxide source sink models predict that the current level of atmospheric CO? Will be doubled by the latter part of the twenty first Century (Witterwer, 1998). This was also supported by the scientists of Ohio State University, USA (Anonymous, 2002) according to whom the CO? levels would become double by the end of twenty first Century.Second there is increase in truly global. The earth’s atmosphere is very effective in dispensing emissions from whatever the source, be it natural or man made.Third, with the average level of CO? rising there is an annual oscillation of the Earth’s atmospheric CO?. The atmospheric CO? level begins to fall in the spring and continues through the summer months. In the late autumn, there is resurgence of CO? into the atmosphere. This results in new heights by mid winter. With an amplitude increasing by about 1.66 ppm each year, It seems that concentration amount of Earth’s biomass is either increasing or is steady.
A new study reveals that rising level of CO? in the atmosphere could be a boon for agricultural crops, as this green house gas helps crop plants to grow and reproduce more (Anonymous, 2002). But this boon comes with a price, says Peter Curtis-a professor of evolution, ecology and organismal biology at Ohio State University (USA) as greater growth and reproduction may hurt the nutritional value of crops. According to Curtis, while crops may be more productive, but the resulting produce will be of lower nutritional quality. Nutritional quality decreases because when the plant yield more seeds under higher CO? levels, the seeds contain less nitrogen. Less nitrogen means less proteins as the former is a critical component for building protein in animals after taking food.
Climate change and food security: According to the latest report of Intergovernmental Panel and Climate Change (IPCC), the temperatures are likely to rise by 1.1 to 6.4 degree Celsius by 2100 (Shiv, 2007). This climatic change is also projected as food security, with decline in rice yields by 15 to 42 percent and wheat yields by 3 to 4 percent loss to agricultural revenues would be 12.3 percent in India. Because of climate change 9 percent Gross Domestic Product (GDP) could be wiped out.
Climate Change and marine habitat
Apart from affecting the agricultural production, climatic change also threatens marine habitants and livelihood of people who depend upon them. The oceans have absorbed approximately half of the CO? produced during the past 200 years, producing carbonic acid and lowering the pH of the surface sea water. This would affect the process of calcification by which animals such as corals and mullsues make their shells from calcium carbonate.
The rising levels of the seas in the coastal areas will damage nursery areas for fisheries. The change of the climate also predicts coastal erosion due to a rise in sea levels of about 30-40 cm resulting from faster melting of glaciers.
Climate and floods
Changing climate could be leading to increased river flows in many parts of the world. Fast melting of the glaciers in the Himalayas and Hindukush ranges would affect half a million people in India alone because of excessive flooding in coastal areas, and can also increase the salinity of the ground water in the Sunderbans and Surface water in coastal areas.
Owing to increase in salinity the farmers of the area have to explore changing crops suitable for saline/alkaline soils.
Melting of Glaciers and Their Impact
Two separate studies conducted by the climate researchers and the space agency NASA, showed that parts of Antarctica are steadily melting. After melting the glaciers are flowing into Antarctica’s Weddell Sea (Anonymous, 2004). Large ice shelves in Antarctica Peninsula disintegrated in 1995 and 2002 as a result of climate warming. These ice shelves did not affect sea level as they melted. A drastic change has been seen in just 15 years in 240 km of coastline. The affected area is at far northern tip of the Antarctica (just south of Chile and Argentina). Temperature there have risen by up to 2.5 degree Celsius in the past 63 years faster than almost any region in the world. In the past 53 years ice shelves in the region have lost more than 13,500 km² of area.
Geologists of Geological Survey of India have found that Himalayan Glaciers are reducing by 15m every year. According to Vasudeva (2007) Gangotri Glacier is receding by 25m every year, Pindari Glacier by 23m every year, Dokriani by 18m every year and Sonapani by 17m every year. According to Working Group-ll of Inter governmental Panel on climate change, the Himalayan glaciers are receding faster than any other part of the world. Himalayan glaciers faced with the danger of receding and causing havoc with the regional ecology. India has taken up the matter with China for a joint solution to the problem of climatic change (Anonymous 2007). The melting of Himalayan glaciers is an important issue because it can have catastrophic effect on the ecology of not only of the region but while of world also. Scientists of Chinese Academy of Sciences have found rapid melting ultimately. Climate change of glaciers of the Tibetan Plateau, the melting of the glaciers will trigger more droughts, more expanse of deserts and increasing of sand storms.
Climate change woes for Agricultural Production in Kashmir: Climate change is affecting rainfall and snowfall patterns, which in turn affect food production in Jammu and Kashmir. Vegetation production is sliding. The saffron the oil seed crop is down by 76 percent, according to a research by a non-governmental organization Action-aid International which included in depth interviews with farmers and shepherds across the state.
(The author is Ex-Associate Dean Cum Chief Scientist KVK-Jammu, SKUAST-J)
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