CLIMATE CHANGE AND CROP VULNERABILITY IN NIGERIA

In Nigeria, food insecurity remains problematic due to dislocations in the agricultural productivity pathways. Food preferences and utilization patterns are skewed in favor of crop-based staples, which availability in quantity and quality, depend on the aggregate crop output. Unfavorable environmental conditions such as caused by climate change would c reate some level of vulnerability of the crops and thus have implication on food security. Two compone nts of the Agricultural Value Chain, production and storage, appear to be most responsive to change s in environments with production being the most vulnerable since all the activities involved in the process of production occur in the fields and are weather -dependent. Climate change – directed irreg ularities or deviation from the normal seasonal patterns such as onset and duration of wet and dry periods, short and prolonged dry spells clearly manifest in various levels of crop vulnerability. I t would therefore appear that a sustainable crop-ba sed agricultural system can only be achieved where crop vulnerability is considerably minimized. If clima te change effects can be incorporated in the design an d implementation of national development programs right away, it will help to reduce vulnerability, s tabilize food production and better secure liveliho ods. The ecosystem approach with crop rotations, bioorga nic fertilizers (e.g., from legumes) and biological pest controls, improves soil health and water reten tio , increases fertile top soil, reduces soil eros ion and maintains productivity over the long term.


Agriculture and the Value Chain.
Agriculture is understood as all the productive occupation of man that mobilize various forms of resources(natural human and material) to produce or provide food fiber and other forms of raw materials and their transformation into various utilizable or consumable forms. This may be explained in the context of the agricultural value chain which involves the components of production, processing, storage and marketing (  Fig.1). The separate or the sequences of combined activities involved in the components generate outputs of value. Production is a critical "take off" base or "kick starter" of the value chain especially in crop agriculture, as its quantum outputs and supplies per unit time determine the quantitative input requirements of the other components. Storage has its peculiar constraints as substantial supplies from the production components could be lost due to biodegradation or pest complexes while in storage before or after processing or marketing.
The two components-production and storage appear to be most responsive to changes in environments with production being the most vulnerable since all the activities involved in the process of production occur in the fields and are weather dependent. It would therefore appear that a sustainable crop-based agricultural system can only be achieved where crop vulnerability is considerably minimized.

Crop Vulnerability and Food Security.
In Nigeria, food insecurity remains problematic due to dislocations in the agricultural productivity pathways. Food preferences and utilization patterns are skewed in favor of crop-based staples, which availability in quantity and quality, depend on the aggregate crop output. Unfavorable environmental conditions such as caused by climate change would create some level of vulnerability of the crops and thus have implication on food security. Good knowledge and understanding of the crop as a system and its responses to the environmental history in relation to climate change would be of immense help in the development of strategic options for reducing crop vulnerability. The objective of this paper therefore seeks to provide that understanding .The paper specifically seeks to: • discuss climate change, its realities and predictions in Nigeria • discuss vulnerability of crop agriculture in Nigeria to climate change and its implications for food security • enumerate opportunities available for development of adaptive capacity of Nigerian crop agriculture to climate change to ensure food security.
• point out constraints to development of adaptive capacity/mitigation mechanisms of crop agriculture to climate change. • make recommendations.

METHODOLOGY:
The methodology adopted in this paper is extensive review of literature on climate change, its influences on crop agriculture, adaptive/mitigation mechanisms, the authors' experiences in the field and their reasoned guesses in this rather novel area of agricultural research in Nigeria.  Okigbo (1991) and modified from Goodland and Irwin (1975 The shrinking size and water-holding capacity of Lake Chad, ravaging floods in both north and south of the country occasioned by severe storms and erratic rainfall, desertification and prolonged dry season with high temperatures in most parts of Nigeria, may be warning signs of the reality of climate change. Agriculture is highly sensitive to climate variability and weather extremes, such as droughts, floods and severe storms. The forces that shape our climate are also critical to farm productivity. Changes in rainfall can affect soil erosion rates and soil moisture, both of which are important for crop yields. The IPCC (Intergovernmental Panel on Climate Change) predicts that precipitation will increase in high latitudes, and decrease in most subtropical land regions-some as much as about 20 per cent. While regional precipitation will vary, the number of extreme precipitation events is predicted to increase (IPCC, 2007).
At increasing atmospheric concentrations, greenhouse gases are projected to raise the average world temperature, lead to a rise in sea levels and change seasonal and geographic precipitation patterns. These changes are expected to severely impact agriculture, ecosystems, water resources, coastal areas and human health (Santhaye and Ravindranath, 1998). The IPCC's Fourth Assessment Report summary for Africa describes a trend of warming at a rate faster than the global average, and increasing aridity. Key attributes of the IPCC's Fourth Assessment Report for Africa, sourced from Christensen et al. (2007) highlighted, among other things, the following: Warming is very likely to be larger than the global annual mean warming throughout the continent of Africa and in all seasons, with drier subtropical regions warming more than the moist tropics It is unclear how rainfall in the Sahel, Guinea Coast and southern Sahara will evolve

Major contributory factors to climate change in Nigeria
The Tide Online Newspaper of 18 th January, 2011 noted that there was massive deforestation going on in Nigeria, and that deforestation was the next thing that came to mind after gas flaring whenever the issue of climate change is mentioned in Nigeria. Deforestation, poses a lot of danger in that, the forest acts as carbon sink so when the forest is destroyed, the carbon in there is released into the atmosphere. The report further stated that deforestation and gas flaring were the major contributors to carbon emission in Nigeria, and regrettably, the laws protecting the forests in Nigeria have weak mechanisms of enforcement.

Climate change: A Global Concern
Climate change is posing undisputed challenges in all sectors of human endeavor. The general consensus is that green house gas (G.H.G) emissions account for the highest percentage variability in climate change, with clearly devastating effect on water supply, agriculture (crops, animals, forestry, fisheries), transport and health with agriculture exhibiting the highest vulnerability. (Grain,2010;IPCC,2007;Margulls,20 10). Several countries of the world have peculiarities on the effects of climate change on their diverse sectors of national livelihoods. Most of these countries are developing adaptation and mitigation strategic plans on immediate to shortterm to long -term basis. (Agoumi,2003) Some have attempted to characterize the nature of the effects of climate change for the purpose of identifying the most vulnerable sectors and the patterns of vulnerability for determining the forms of adaptation and mitigation measures (Rudd,2010).

Climate Change: Some Forms and Consequences
The realities, forms and consequences of climate change remain undisputed. Some of the characteristics of climate change and the associated consequences are highlighted in Table  1.  (Margulls, 2010).
• Rise in sea levels; changes in seasonal and geographic precipitation patterns, characterized by more intensive rainfall, more frequent floods, droughts and heat waves.
2.Trends of warming in Africa likely at a rate faster than the global average (IPCC,2007) • Ecosystem dislocation with high vulnerability in crop agriculture and water resources (Santhaye and Ravindranath, 1998). High temperature may be beyond the range of tolerance for current crop varieties and cultivars (Adejuwon,2006). 3. Precipitation increases in high altitudes and decreases in most sub-tropical regions as much as 20% (IPCC, 2007).

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Flooding at low-lying areas become more vulnerable to inundation from sea level.

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Rapid rate of organic matter decomposition.

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Reduced crop growth (Agoumi,2003). 4. Changes in onset of rainy season and the variability of dry spells.
• Reduced crop growth and may lead to crop failures (Kalu, 2008;Odo, 1999). 5. Destruction of forest ecosystems through deforestation, burning and cultivation methods that reduce tree density (Rajasekaran and Warren, 1994 6.Combination of shifts in temperature, vegetation cover and species distribution as well as the associated alteration in the dynamics of drought, rainfall and heat waves (Ziervogel et al.,2008):the interplay of deforestation and burning (Fig.2).

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Multiple stresses on the biophysical, social and institutional environment underpin crop production.

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Weakening of economics livelihood s and food security (Smith and Barchiesi, 2009).

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Secondary stresses leading to pest and disease complexes • Increased competition for resources and degeneration of regional and ecotypic biodiversity.

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High vulnerability in crops Disastrous impacts on artesanal fishing, wildlife species and forest products.

Climate Change and Nigerian Agriculture Agro-ecological delineation.
Nigeria is delineated into distinct agroecological zones (Kowal and Knabe, 1972). The major zones are the Rain forest in the southern parts, the Guinea savanna in the central and northern parts, and the Sahel in the extreme northern parts. Each zone is characterized by distinct and often overlapping ecological features typified by patterns of vegetation, soil types and land formation, rainfall, temperature, relative humidity, solar radiation which interplay in various forms to determine crop adaptation, biodiversity forms, demographic features and consequently the farming system of the areas.

Seasons and crop vulnerability
Agricultural activities in Nigeria are governed by two distinct seasons of the year, namely the rainy (wet or growing) season and the dry season with ecological variation in the onset and cessation of each. The southern ecologies are generally characterized by long rainy periods of about eight months (March to end of October) and short dry period of about four months (November to February), while the northern ecologies are generally marked by short rainy periods of 5-6 (May/June to October) and longer dry periods of 6-7 months (October/November to April/May/June). Nigerian agriculture is known to be 90% rain-fed. Irrigated agriculture (with vast potential) is scanty and is mainly located in the northern parts of the country, producing mainly vegetable crops. Water supply therefore is a critical factor of the overall crop productivity. Annual crops (for example) must complete their life cycles within the period of the growing season. It would therefore be bad for a plant to flower so late in the season that the fruit and seed development could not be completed before the onset of the dry season. In the same way, biennial plants need to have sufficiently developed underground storage organs during the wet season to enable them endure the dry periods and continue growth and production in the succeeding year. Similarly, perennial plants possess some mechanisms for timing of their dormant periods and must flower at an appropriate time of the season of the year for fruit and seed development (Bidwell, 1974).Climate change -directed irregularities or deviation from the normal seasonal patterns such as onset and duration of wet and dry periods, short and prolonged dry spells clearly manifest in various levels of crop vulnerability. Rainfall appears to be the most critical factor that accounts for substantial percent of the variability in crop vulnerability. Rainfall moderates or determines the varying magnitudes of drought, flooding, erosion (Agounmi,2003) and pest and disease build ups or incidences when in interplay with associated temperature and relative humidity (Okigbo,1991;Ziervogel et al., 2008). The separate or combined effects of these determine the degree of vulnerability of the crop under an eco-typic environment.

Vulnerability Rating of Some Selected Crops
From the fore going, it would appear that the major contributors to crop vulnerability due to changing environment are drought, flooding, erosion, pests and diseases. The vulnerability rating of some selected crops based on these and the possible sources of the response patterns are presented in matrix (Table2)
-desiccation of pollen grains leading to poor/zero seed setting (most vulnerable at tasselling and silking. -Poor to zero grain filling (most vulnerable at grain filling stage) leading to physiologically immature seeds.
Overall rating = 4 due to: -ineffective pollen, poor fertilization, poor seed setting and grain filling leading to poor to zero grain production (most vulnerable from tasseling to grain filling)).
Overall rating = 5 due to: -submerging of root system. -physiological capacity of roots for water and nutrient absorption is blocked -discolouration, wilting and death of the aboveground parts -zero production where water logging is extended to occur frequently. More entomological research to identify and manage/control emerging insect pests and diseases.
-delayed establishment of transplants -reduction in weight and number of seeds per panicle -relatively high incidences of Overall rating = 2 due to: -high tolerance to heat and drought -Possesses low transpiration rate -most vulnerable at seedling stage Overall rating = 5 due to:submerging of root system. -physiological capacity of roots for water and nutrient absorption is blocked -discolouration, wilting and death of the aboveground parts -zero production where Overall rating = 3 due to: -complete washing away of stands -root exposure -lodging -Most vulnerable from Overall rating = 3 due to: -high susceptibility to Striga infestation -stemborer infestation for early planted crops. -Fungal infestation (moulds and smut) at  Building adaptive capacity enables communities and nations to mobilize the decisions and resources needed to reduce vulnerability and adapt to climate change (Nelson et al.,2007).Building adaptive capacity means strengthening attributes including the availability of information and skills, access to technologies, access to economic resources and the effectiveness of institutions (Munasinghe and Swart,2005). Coping with the impact of climate change on crop agriculture will require careful management of resources like soil, water and biodiversity (Sahai, 2010).Recommendations from National Conference on Climate Change and Food Security for India organized by Gene Campaign along with ActionAid as recorded by Sahai (2010) unveils opportunities for Nigeria.
Making agriculture sustainable is the key and this is possible only through production systems that make the most efficient use of environmental factors of production (soil, water, air, light, etc.) without damaging these assets. If climate change effects can be incorporated in the design and implementation of national development programs right away, it will help to reduce vulnerability, stabilize food production and better secure livelihoods. Developing sustainability in agricultural production systems rather than seeking to maximize crop, aquacultural and livestock outputs, will help farming communities to cope with the uncertainties of climate change. The ecosystem approach with crop rotations, bioorganic fertilizers (e.g., from legumes) and biological pest controls, improves soil health and water retention, increases fertile top soil, reduces soil erosion and maintains productivity over the long term. The more diverse the agro ecosystems, the more efficient the network of insects and microorganisms that control pests and disease. Building resilience in agro ecosystems and farming communities, improving adaptive capacity and mitigating green-house gas emissions are the ways to cope. This can be addressed at local, state, national, regional and global levels: Local: The real action for both mitigation and adaptation will have to be at the local level. The pursuit of sustainable agricultural development at the local level is integral to climate-change mitigation and combating climate change effects is vital for sustainable agriculture. Location specific technologies will need to be developed at the level of the agro-ecological unit, to make agriculture sustainable and minimize losses to food and nutrition. Universities of Agriculture and Universities with agriculture faculties may be mandated to generate these adaptive technologies with adequate back-up funds for the research programs.

State:
Conserving the genetic diversity of crops and its associated knowledge, in partnership with local communities must receive the highest priority in each state of the federation.
A scientific knowledgeintensive, rather than input-intensive approach should be adopted to develop adaptation strategies. Traditional knowledge about each community's coping strategies should be documented and used in training programs to help find solutions to address the uncertainties of climate change, build resilience, adapt crop agriculture and reduce emissions in each state.
National: Adaptation strategies have long duration and need to start NOW.
• Appropriate policy and budgetary support for mitigation and adaptation actions is needed.
• Multiple food and livelihood strategies are needed in rural areas to minimize risk. Food inflation must be contained at all costs. It will worsen with climate change as more frequent and unpredictable droughts and floods will result in shortfalls in food production. Just a few flash floods in Sokoto, Kebbi, Jigawa, Benue, Nasarawa States in 2010 may lead to a loss of thousands of tonnes of rice, maize, millet, sorghum and cowpea, causing prices to go through the roof.
• A carefully planned program for strategic research, along with dedicated funding, is needed to develop solutions to cope with the impact of global warming on crops, livestock, fish, soil etc. Renewable energy must be part of our mitigation and adaptation strategy and we should focus on bringing it to scale.
• Pro-poor climate change adaptation strategies should be emphasized as a policy at all levels of governance (local, state, or federal). This can be achieved through (i) Enhanced knowledge about agricultural development pathways that lead to better decisions for climate mitigation, poverty alleviation, food security, and environmental health, used by national agencies.(ii) Improved knowledge about incentives and institutional arrangements for mitigation practices by resource-poor smallholders used by farmers (including farmers' organizations),project developers and policy makers (CIAT,2010). Regional: Regional strategies for mitigation and adaptation across similar agro-ecologies will help all countries of the West African sub-region to protect their agriculture and food production. The glimpse of a potentially dire future, provided by scientific observations and predictions, affords African farmers the possibility of collectively responding to new conditions, using traditional knowledge and in-situ methods, supported by agricultural research and extension, to create the seeds and production systems necessary to cope with a rapidly changing environment (ACB, 2009).
Global: Nigeria must negotiate hard to ensure that the emission reduction pledges or commitments are sufficient to ensure at least 50 percent likelihood that the global temperatures rise is capped at 2 0 C. If this is not done, the impact on agriculture and food security in developing countries will be devastating. Rising temperatures will be beneficial for the agriculture of cold temperate regions since warmer conditions will allow their single crop zones to become two, even three crop zones. Given that agriculture is the lifeline of the developing world and will bear the worst brunt of climate change, Nigeria must insist that developed countries must reduce their own agriculture emissions while at the same time paying for adaptation, especially in the agriculture sector, consistent with the polluter pays principle. Nigeria should be able to tap from the Global Environment Facility (GEF) initiatives on Climate Change Adaptation and Clean Development Mechanism (CDM) of the Kyoto Protocol for carbon trading (UNDP/FME, 2008). It must also be noted that climate change holds many dangers-and water is at the centre of its impacts (Smith and Barchiesi,2009).There are numerous options for adapting to climate change impacts on water, and there are variety of enabling mechanisms which need to be developed and coordinated for adaptation to be effectively implemented. Coping with floods, drought, storms and sea-level rise will depend on water storage, flood control and coastal defense. However, providing these functions simply by building infrastructure-such as dams, reservoirs, dikes, and sea walls-will not be adequate. By itself such infrastructures can weaken resilience, especially in a changing climate where the historic hydrology is no longer a viable guide to the future, because of damage caused to livelihood and the environment (Palmer et al., 2008).The environment has a critical role to play. It must be kept intact as much as possible. The environment itself is infrastructure for adaptation-It is 'natural infrastructure'. According to Nelson et al. (2007), when based on principles of good governance, sound investment strategies and learning from integrated water resources management, integrating natural infrastructure into adaptation builds resilience.

Constraints to development of Adaptive capacity of Nigerian Crop Agriculture to Climate Change.
The constraints/barriers are numerous, but a few are listed here: 1. Although some level of awareness may exist in the urban areas of Nigeria on the effect of climate change on agriculture, there is a near-complete absence of the knowledge of this phenomenon at the local level where more than 90% of crop production takes place. This fact is corroborated by Ziervogel et al. (2008) who reported that while awareness of and reference to climate change are both increasing, much of these are based on media messages, or highly aggregated data from IPCC (DDC) and GCM models. The link between climate change information and adaptation practitioners on the ground remains largely non-existent and many adaptation practitioners in the agricultural sector still rely on generalized assumptions about how the climate change will change or derive very general information about climate change and its impacts from the IPCC reports. Adequate awareness of the negative effects of climate change at the local level could generate pressure on government to tackle climate issues more seriously. A large scale climate literacy program is necessary to prepare farmers, who are today bewildered by the rapid fluctuations in weather conditions that affect their agriculture. Their traditional knowledge does not help them to manage these recent anthropogenic changes.

2.
Finance is central to climate change adaptation/mitigation strategies. Nigeria is listed as one of the developing countries that has committed only $0.2 billion out of an estimated $15.93 billion on installing renewable and low-carbon electricity generating technological option to mitigate climate change (GCN,2010). Even at the international arena, finance is central to negotiations on climate change. The 1992 United Nations Framework Convention on Climate Change (UNFCCC) obliges industrialized countries to help the developing world meet the costs of reducing greenhouse gas emissions. However, no agreement has yet been reached concerning the overall sum of the developing country climate costs or how the finance should be raised and spent (GCN, 2010).
3. Deforestation. Around 80% of agricultural emissions, including deforestation, occur in developing countries (World Bank, 2007).The unabated excessive exploitation of timber from our forests without a commensurate afforestation programs is a great challenge to climate change mitigation strategy, with consequent effect on food security. Although some laws to guide against excessive timber exploitation exist in the country, implementation and prosecution of offenders is poor, mainly due to corruption. 4. Low-level research on climate change issues that relate to agriculture and food security. Absence of consistent relevant research to tackle identified problems that militate against climate change adaptations and also research to develop appropriate adaptive strategies to ward off the effects of climate change in Nigeria. This problem is also acknowledged by the international community. CIAT (2010) stated that AR4 recognises that, with only a decade of research on climate change adaptation, considerable knowledge gaps remain concerning adaptive capacity of agriculture. 5. Inadequate expertise on climate change adaptation in Nigeria. Although some expertise exists at the national level, located in the Special Climate Change Unit of the Federal Ministry of Environment and also at International Centre for Energy, Environment and Development (CEED), the scenario at the state and local government areas is the complete opposite. There is lack of capacity both in human resources and computational capacity to expand the available database. 6. Lack of reliable meteorological data. One of the main barriers to producing climate change information remains the lack of reliable meteorological data. This is especially true for complex environments where higher concentrations of station data are needed to capture the complexity of the terrain. 7. Ignorance of global weather conditions Most farmers base their decisions on short-term weather and seasonal climate variability, and stand to gain little from engaging with complex world of climate projections and its difficult-to-apply messages. 8. Poverty. The report of the First National Environment Summit organized by UNDP and the Federal Ministry of Environment, Housing and Urban Development in 2008 in Abuja indicated that poverty was one of the major constraints to the development of capacities to tackle climate change .The report also pointed out that Nigeria, like other African countries had limited capacity to cope with current global warming and its associated challenges.

CONCLUSIONS.
Crop agriculture is the major sector upon which the majority of Nigeria's rural poor depend. The shrinking size and water-holding capacity of Lake Chad, ravaging floods in both north and south of the country occasioned by severe storms and erratic rainfall, desertification and prolonged dry season with high temperatures in most parts of Nigeria, may be warning signs of the reality of climate change. Crop agriculture is highly sensitive to climate variability and weather extremes, such as droughts, floods and severe storms. The forces that shape our climate are also critical to farm productivity. A Nigerian study applied the EPIC crop model to give projections of crop yield in the 21 st century. The study modeled worst case climate change scenarios for maize, sorghum, rice, millet and cassava. Making agriculture sustainable is the key opportunity to climate change adaptation in Nigeria and this is possible only through production systems that make the most efficient use of environmental factors of production (soil ,water ,air, light, etc.) without damaging these assets. Pro-poor climate change adaptation strategies should be emphasized as a policy at all levels of governance (local, state, or federal).Although several constraints militate against climate change adaptation strategies to provide food security in Nigeria, research efforts should be intensified in this direction with appropriate government and private sector involvement.

RECOMMENDATIONS
National strategic plan for climate change: There is NOW a dear need to have a national strategic plan in place to tackle the ominous consequences of climate change on agriculture and to harness any possible inherent advantage .Such a plan would involve the critical and relevant stakeholders, namely,Interministerial agencies, National Agricultural Research Systems (NARS)-Agricultural Research Institutes, Universities of Agriculture, Faculties of Agriculture in the Universities, Colleges of Agriculture and relevant Polytechnics,Federal Ministry of information and the National Orientation Agency, with the Federal Ministry of Environment co-coordinating Characterization Study: It is needful to carry out an indepth characterization study on the impact of climate change on Nigerian agriculture with the aim to isolate specific areas of agriculture most prone to the devastating effects of the change and to evolve adaptive and mitigation strategies in the short and long term.

Human capacity building and computational capacity development to expand available database:
Greater expertise has to be developed in agricultural climatology and instrumentation to handle the highly sophisticated instruments for computation and accurate predictions of weather/climate and effects on agriculture and agric-related businesses in both the short and long term. .A carefully planned program for strategic research (breeding for resistance/tolerance to drought, new emerging pests and diseases, development of production systems necessary to cope with a rapidly changing environment,etc.) along with dedicated funding, is needed to develop solutions to cope with the impact of global warming on crops, livestock, fish, soil etc.

Conducting a capacity survey of National Agricultural Research Systems
This is for the purpose of identifying the institutions with relatively higher comparative advantage in handling specific components of climate change as they affect agriculture. We recommend that deforestation, reckless land clearing practices, unorthodox and careless use of agricultural chemicals must be curtailed to preserve the natural environment as an adaptive strategy to also halt the effects of climate change. Government at all levels (federal, state, local) must be deliberate about this. Political will on climate change should take cue from other countries that are infusing a substantial percentage of their annual budget to make for adaptation/mitigation of the adverse effects of climate change. Public enlightenment on climate change Intensification of public enlightenment on climate change at the local and state levels require urgency. National Action Committee on Climate Change (NACCC).Climate change could be as devastating as HIV/AIDS, if not more. There is therefore an urgent need for a National Action Committee on Climate Change to be set up to serve as the Technical Committee on climate in Nigeria.