May 24, 2013 | 05:53 AM (BD Time)

24 May, 2013 Friday

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Climate change affects nutrition-level

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Sharmin Sultana :
Climate change and its impact on human life is very important issue at present time. Climate is changing because of increasing green house gas as well as world temperature. As a result different natural calamities like flood, drought, and cyclone are more frequently occurring now. Climate change has negative effects on food security and nutrition. For example droughts and water scarcity diminish dietary diversity and reduce overall consumption of food. This may lead to malnutrition problems including undernutrition, protein-energy malnutrition or micronutrient deficiencies.
The change in climate is effecting the production of rice, wheat, corn, soybeans and potatoes which are staple food of billions of people in the world. According to some studies the rising temperatures of climate can make rice spikelets (the slender branches that contain rice flowers) sterile. This will affect Asia most, where 90 per cent of the world's rice is grown and consumed.
Researchers are focusing attention in agriculture sector to ensure the supply of food but quantity should be increased with proper quality.  Few people know that rising levels of carbon dioxide (CO2) is   affecting the nutritive value of many basic food crops. In general it seems that rise in   CO2   level will increase the production of food, because it increases photosynthesis and lower the requirement of water.   CO2   is stimulates plant growth like wheat, rice and cereals which are supplying the calorie requirements of poor people but the nutritional value of these potentially bumper yields is unlikely to improve.  Extra CO2 is often converted into carbohydrates such as starch, meaning that the relative levels of other components in food may fall. For an example, since 1960 about 20% rises in atmospheric CO2 may have already caused a significant decline (5-10 percent) in protein concentration in wheat flour.
CO2 may lower the water flow through a crop which affects the uptake of micronutrient from soil and decrease concentrations of nutrient like sulphar, magnesium, iron, zinc and manganese.  This can make hidden hunger situation worse.  Besides that crops are more vulnerable to insects, infection and pest by altered weather patterns. As a result crop yield decreases which force farmers to use expensive and harmful pesticides on their crops. According to Professor Lesley Hughes, the changes in plant "architecture" will weaken the root system and it will be harder for plant to survive in adverse weather.
Drought may strain agricultural productivity and could result in increased food prices and food shortages. Sea level rise increases the risk from extreme weather events in coastal areas, salt-water entering freshwater drinking supplies is also a concern for these regions, and increased salt content in soil can hinder agricultural activity in coastal areas.  Increased carbon dioxide concentrations in sea water may cause oceans to grow more acidic and is likely to affect fisheries and the food supply in certain regions of the world.
The changes in different sectors can affect nutritional status a lot. More than 1 billion people worldwide are malnourished according to the UN Food and Agriculture Organization. A study suggests that the rises of temperature to 2 to 3 degree Celsius will increase the number of people at risk of hunger by 30-200 million. Malnutrition generally results from a lack of either protein or micronutrients such as iodine, vitamin A or iron, which boost immunity and healthy development. Malnutrition contributes to at least half of the 10.8 million child deaths each year, increase the effect of childhood diseases such as measles, malaria, pneumonia and diarrhoea, and can have long-term effects on cognitive development and economic productivity.
There is evidence that low income countries are mostly facing these problems even though they have little contribution to the cause of these problems.
In Bangladesh frequent flood, droughts and cyclones of last two decades have caused extensive economic damage and have impaired livelihoods. Agriculture, a key economic sector accounting for nearly 20 per cent of GDP and 65 per cent of the labour force, is greatly at risk. Climate change is predicted to reduce rice production, Bangladesh's main crop, and increase the country's reliance on other crops and imported food grains. Overall, agricultural GDP in Bangladesh is projected to be 3.1% lower each year as a result of climate change. These risks will not only affect those in the agriculture sector, but all the way up the food chain to household consumption.
It is clear that climate change has major impacts on global food security which is threatening for nutrition and hunger around the world. So to reduce the impact of climate change, food quality should be improved. Nitrogen fertilizer can be used to increase food quality.
But it may be too expensive, or not available, particularly in developing countries. Biofortification is a long term option for developing nutritionally improved crops (increased protein or micronutrient levels). Besides that we should also try to find new ways to improve food and nutrition sector and reduce malnutrition.