Towards global climate change mitigation: assessment of an afforestation option for Nigeria

This paper assesses the potential of an intensive afforestation program as a measure of reducing the atmospheric concentration of carbon in Nigeria. The results presented are based on the recently completed Nigerian Country Studies Program on Climate Change Mitigation. A comprehensive mitigation analysis process (COMAP) model was employed to carry out detailed cost/benefit evaluation of the mitigation option. The end-use based scenario adopted was considered the most appropriate strategy to sustainably implement the mitigation option in Nigeria.The analyses showed that the country could significantly reduce net carbon emission while at the same time meet all her essential domestic wood needs, if approximately 7.5×10⁶ ha of wasteland could be committed to an afforestation program over the 40 year period of projection. The initial cost of establishing such forest plantations, taking cognisance of the opportunity cost of land averaged at about US$500/ha, or in carbon terms, a unit cost of about $13 per tonne of carbon. In terms of carbon flow, if all the end-product based plantations considered (i.e. fuelwood, poles, pulpwood, sawlogs and veneer) were fully established and maintained, it was estimated that by the year 2030, the total carbon stored in the afforested land would be about 638.0×10⁶ t of carbon with an annual incremental rate of 16.0×10⁶ t of carbon. Other economic indicators (i.e. net present value of benefits, present value of costs and benefit for reduced atmospheric carbon) when evaluated showed that the afforestation option could be economically viable even when the investment capital was discounted at rates ranging from 9 to 33 percent for different wood products. It should be noted, however that implementation of such a program would require huge sums of money and a high degree of commitment on the part of Federal, State and Local governments if the associated financial, social and environmental benefits were to be derived.