The process of capturing and long-term storage of atmospheric carbon dioxide is known as carbon sequestration. It is helpful in mitigating global warming. Sequestration of atmospheric CO2 can be achieved by reducing fossil fuel consumption and identification of sinks for long term storage of carbon dioxide. Terrestrial sink includes plants and soil. Both of them are known as main storage house of carbon dioxide.
Agriculture is central to economic growth and development of Pakistan. No doubt its share in GDP is 21.4 percent and it employs 45 per cent of the total countrys labour force. But, agriculture also contributes in emission of Greenhouse Gases (GHGs). Major Greenhouse Gases CO2, CH4, and N2O are also added by agricultural activities. These gases capture long wave energy and cause increase in temperature within the atmosphere. According to 5th assessment of intergovernmental panel on climate change (IPCC) 0.74 0C increase in average global temperature was observed during the last century. Further increase by 1.8-4.0 0C in global temperature and 0.18 to 0.59 m in global sea level is projected by the end of current century. Carbon sequestration in agricultural soils, through the use of proper management practices, can mitigate this trend. Agricultural soils are sunk or source of carbon depend on the actual organic matter contents in the soil. Pakistan soils are deficient in organic matter contents. So, we need sequestration of atmospheric CO2 and make it the part of Soil Organic Carbon (SOC). An increase in SOC will improve soil structure, aggregation, porosity and biodiversity vis-a-vis less vulnerable to climate change.
The Carbon Foot Printing (CFP) is the process of measuring the exclusive total amount of Greenhouse Gases that are directly and indirectly added by an activity or are accumulated over the life stages of a product. There are two types of carbon foot printing i.e. primary and secondary footprint. In primary foot printing direct emissions of CO2 from the burning of fossil fuels is measured while secondary footprint involves measures of indirect CO2 emissions from the whole life cycle of products. In Pakistan, no work on greenhouse gases emission monitoring at farm level has been done yet. A farmer can estimate emission of GHGs at his farm by using Cool Farm Tool (CFT). This tool can provide estimation of GHGs emission across entire supply chain of a product. Carbon Foot Printing at farm level or even at site scale will provide opportunities to test alternate management practices. The potential of soil to sequester atmospheric CO2 and dynamics of soil organic carbon transformation can be quantified by measuring of GHGs emission from soil using models and remote sensing approach. Cool Farm Tool and Models (EPIC or EPEX) can help us in identification of the best agricultural management option to boost sequestration of atmospheric carbon dioxide.
Clean Development Mechanism (CDM) was developed under Kyoto protocol of the United Nation Framework Convention on Climate Change (UNFCCC) to explore options to mitigate the impacts of climate change. CDM assists the developing countries to implement project activities that reduce Greenhouse Gases emission in return for generating Carbon Credits/ Certified Emission Reduction (CERs). Ministry of Climate Change, Pakistan, has deposited instrument of accession to the Kyoto protocol and has become eligible to benefits from CDM. For this purpose the Climate Change Division has been declared as Designated National Authority (DNA). The CDM cell has been established in Pakistan in order to create awareness among masses, implementation of CDM strategies and promote CDM projects development in the country. In Pakistan different organizations are developing CDM projects in various sectors and are getting carbon credits. Still no project in agriculture field has been registered under CDM. Nevertheless, agriculture is also GHGs contributor in Pakistan. By using above mentioned tools, we can take step to get carbon credits with introduction of best management practice in agriculture field especially shifting the anaerobic to aerobic rice cultivation and can claim Carbon Credits by observing in Clean Development System.
The writers are associated with the Agro-Climatology Lab. Department of Agronomy, University of Agriculture, Faisalabad, Pakistan.