A CRITICAL ANALYSIS OF CLIMATE CHANGE FACTORS AND ITS PROJECTED FUTURE VALUES IN DELTA STATE, NIGERIA Publisher: Asian Economic and Social Society ISSN (P): 2304-1455, ISSN (E): 2224-4433 Volume 2 No. 2 June 2012. A Critical Analysis of Climate Change Factors and its Projected Future Values in Delta State, Nigeria Emaziye, P. O., R. N. Okoh and P. C. Ike (Department of Agricultural Economics and Extension, Delta State University, Asaba Campus, Asaba, Nigeria) Citation: Emaziye, P. O., R. N. Okoh and P. C. Ike (2012): “A Critical Analysis of Climate Change Factors and its Projected Future Values in Delta State, Nigeria”, Asian Journal of Agriculture and Rural Development, Vol. 2, No. 2, pp. 206-212. Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 206 Author(s) Emaziye, P. O. Department of Agricultural Economics and Extension Delta State University, Asaba Campus, Asaba, Nigeria Email: pemaziye@yahoo.com R. N. Okoh and P. C. Ike Department of Agricultural Economics and Extension Delta State University, Asaba Campus, Asaba, Nigeria A Critical Analysis of Climate Change Factors and its Projected Future Values in Delta State, Nigeria Abstract The study focused on the critical analysis of climate change factors (temperature and rainfall) and its projected future values in the state. The main objective was to determine the trends of climate change factors (temperature and rainfall). And the specific objective was to determine the projected future trends of climate change factors in the state. Multistage sampling procedure was used in the random selection of states, local government, communities and rural households for the research study. Annual mean time series data of temperature and rainfall were collected from Nigerian Meteorological Agency (NIMET). Data were also obtained from structure questionnaire survey. The collected data were analyzed using descriptive statistics, trend analysis and growth model. The study reveals that there were increasing trends of temperature values and decreasing rainfall values in the state. But their projected future values witnessed an increasing trend. The increasing trends in temperature values may lead to a situation were crops will be smothered by excessive heat thereby reducing food production in the state. The study therefore recommends that meteorological station units should be established in the rural farming households in the state where accessibility is extremely difficult. This will make available meteorological data (information) to the reach of the poor rural farming household for the attainment of food production. Keywords: Climate Change, Trend, Climatic Change Factors, Delta State, Nigeria Introduction Climate change has become more threatening to the sustainable development globally. The “mean global temperatures have been increasing in line with precipitation increases since 1850, mainly due to the accumulation of greenhouse gases in the atmosphere” (FAO, 2007). Exposure to climate change, most particularly flooding poses substantial risks to food production in the rural household resulting in food insecurity. Greater rainfall variability and more severe droughts in semi-arid Africa will hinder efforts to enhance food security and combat malnourishment (Schmidhuber and Tubiello, 2007). Given the pronouncement of climatologist on the evidence of global warming, there is concern that climatic impacts on food crop production will be exacerbated in developing countries (Molua and Lambi, 2007). This is in line with the report of Adejuwon, (2004) that Nigerian Agriculture depend highly on climate because temperature, sunlight, water, relative humidity are the main drivers of crop growth and yield. A variety of crops such as maize, yam and cassava produced in Delta state depend on rainfall for their optimum performance. But in line with IPCC (2007a) reported that precipitation levels are on the downward trend. The decrease and irregular rainfall pattern pose a problem that need to be addressed to avoid food shortage in the state. Hence this study will provide an insight to the trends of climate change factors (temperature and rainfall) in the state. The study also addressed the following research questions: 1) What is the trend of temperature values in the state? 2) What is the trend of rainfall values in the state? 3) What are the projected future values of climate change factors in the state? Methodology The Study Area Delta state, located in the South - South geopolitical region of Nigeria was created on the 27 th of August 1991 out of the former Bendel state. At inception, Delta state was made up of twelve political divisions called Local Government areas (LGA’s), later increased to 19 in 1996. Presently there are 25 local government areas in Delta State.(Delta state govt., N.D). The state occupy a land mass of about 17,163 square kilometer with a population of about 4,098,398 persons (NPC, 2006). Geographically located within Longitudes 5 ◦ and 6.4 ◦ E and 5 ◦ 00 and 6.30’, the state is bounded Northwards by Edo state, on the East by Anambra State, on the South East by mailto:pemaziye@yahoo.com Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 207 Bayelsa state and on the South west by the Bight of Benin which covers approximately 160km of the states coastline, (Delta state govt. N.D). Southern parts of the state which is transverse by numerous flat floored rivers that drain into the Atlantic ocean is generally low lying without remarkable hills, consisting of unconsolidated sediments of quaternary age. Some hills can be found northwards within the LGA’s of Ika and Aniocha. The major rivers include the Niger River, Ethiope, Warri, kiagbodo (Aweto, 2002). Drainage is done in the eastern flank by the Niger River via its several distributaries such as the forcados, escravos, and the Warri Rivers and creeks such as the Bomadi creek. Rivers Jamieson and Ethiope rise from the north and northeast respectively subsequently join and form the Benin River which eventually drains into the sea in the west (Online Nigeria, 2003). Delta state shares similar climatic features with other states in the Niger-delta. The general climate is characterized by a long rainy season from March/April through October. The climate in Delta state shows latitudinal fluctuation in humidity ranging from the humid tropical in the south to the sub- humid in the north east. Lessening humidity towards the north is accompanied by an increasingly marked dry season (online Nigeria, 2003) Method of Sampling / Sampling Size Multistage sampling procedure was used in random selection of local government areas, communities and rural households for the research study. Firstly, three local government areas each were selected from each of the three agricultural zones in the state making up to nine (9) local government areas from the twenty-five (25) local government areas. Secondly, two communities from each of the local government areas were selected, making it up to 18 communities. Finally, twenty five rural households were randomly selected from each of the sampled communities making it up to four hundred and fifty (450) rural households. Only four hundred and ten (410) respondents were utilized for this research study. Method of Data Collection Annual mean time series data from Nigerian Meteorological Agency that include the following; temperature, and rainfall from January, 1971 to December, 2009 were collected for the study. Data for this study were also obtained using personal interview and structured questionnaire survey Method of Data Analysis Descriptive Statistics Descriptive statistic was used to summarize the respondents’ socio-economic characteristics of rural farming households in the state. Trend Analysis Line graph was used to determine the trend of the climatic change factors (temperature, and rainfall) in Delta state. Growth Model Growth model was used to predict the future values of climate change factors (temperature, and rainfall). This model was specified as linear, quadratic and cubic equations. The equations are as follows: CHf = a(1+i) t +e (Linear) ………. i CHf = a(1+i) t +b (1+i) 2t +e (Quadratic)….….ii CHf = a(1+i) t +b (1+i) 2t + c(1+i) 3t +e (Cubic)…………iii Where CHf = climate change factors (Temperature and Rainfall) i = Rate of growth t = Time horizon (integer values starting from 1 to 38 years) e = Error term a, b, c and d = Coefficients of the model The cubic functional form that fits the data best fitted was selected. Results and Discussion Socio-economic Characteristics of Respondents in Delta State, Nigeria Primary school level of education dominated the state with large household size of 9 persons. The mean age of respondents in the state is 48 years engaging in farming activities and dominated by male headed households. Most rural farming households were married confirming that they were matured and conscious on the level of climate change factors (temperature and rainfall) in the state. The mean annual income of the rural farming households in the state was N54,702 ($353) revealing a low annual income level due to impacts of climate change in the state. Socio- economics characteristics is shown in Table 1 Trend Analysis of Temperature in Delta State, Nigeria Temperature data from Delta State, Nigeria between 1971 and 2009 shows an increasing trend with a trend coefficient of 0.57 0 C per year (Table 2) and is statistically significant. The minimum value of temperature (30.09 0 C) was recorded in 1976 while the maximum value of temperature (32.60 0 C) was recorded in the year 1976. The standard deviation and mean values of temperature over the period (1971 – 2009) are 0.53 0 C and 31.49 0 C respectively. The trend line had a positive slope of 0.56 indicating that over the time period 1971 to 2009 annual mean temperature in Delta state rose by 0.56 0 C per unit change in time (figure 1). The trend analysis results revealed an increasing trend in mean annual temperature in the state. The increasing trend may lead to a situation were crops will be smothered by excessive heat thereby reducing food production in the state. Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 208 Trend Analysis of Rainfall in Delta State, Nigeria Rainfall record from the Delta State, Nigeria between 1971 – 2009 shows a decreasing trend with the minimum value for the period (189.02mm) recorded in 1977 and maximum value for the period (283.05mm) recorded in 1999 (Table 3). The mean and standard deviation values of rainfall from 1971 – 2009 are 231.41mm and 27.31mm respectively. The trend line had a negatives slope of – 0.38 indicating that over the time period 1971 to 2009 annual mean rainfall in Delta state fell by - 0.38mm per unit change in time (figure 2). This reveals a decreasing trend with the negative value of the trend coefficient of rainfall in the state. Crops needs water for optimum development but with the decreasing nature of rainfall in the state will lead to crop failure thereby resulting in hunger and food insecurity situation in the state if prompt action is not taking. Predicted Future Values of Climate Change Factors in Delta State, Nigeria The future projected values of temperature are; 32.25 0 C, 32.40 0 C, 32.56 0 C, 32.71 0 C, 32.87 0 C, 33.03 0 C, 33.18 0 C and 33.34 0 C for the year 2015, 2020, 2025, 2030, 2035, 2040, 2045 and 2050 respectively (Table 4). There was an increasing trend in temperature in the state. Rainfall projected future values also witnessed an increasing trend. The values of the projected future values of rainfall in the State are: 234.38mm, 246.19mm, 249.02mm, 251.89mm, 254.79mm, 257.72mm, 260.69mm and 263.69mm for the year 2015, 2020, 2025, 2030, 2035, 2040, 2045 and 2050 respectively. Figure 3and 4 shows the projected future upward trend. Conclusion and Recommendation Primary school level of education dominated the state with large household size of 9 persons and a mean age of 48 years. Most respondents were married with a low annual income of N54,702 ($353). The trend line had a positive slope of 0.56 indicating that over the time period 1971 to 2009 annual mean temperature in Delta state rose by 0.56 0 C per unit change in time. The trend line had a negatives slope of – 0.38 indicating that over the time period 1971 to 2009 annual mean rainfall in Delta state fell by - 0.38mm per unit change in time. The trend analysis results revealed an increasing trend in mean annual temperature and a decreasing trend in mean annual rainfall in the state. There were increasing trend in projected future values of temperature and rainfall in the state. The increasing trend may lead to a situation were crops will be smothered by excessive heat thereby reducing food production in the state. The study therefore recommends that meteorological station units should be established in the rural farming households in the state where accessibility is extremely difficult. This will make available meteorological data (information) to the reach of the poor rural farming household for the attainment of food production. Reference Adejuwon, S. A. (2004) “Impacts of Climate Variability and Climate Change on Crop yield in Nigeria”, Lead paper Presented at the Stakeholders workshop on Assessment of Impacts and Adaptation to climate change, conference center, Obafemi Awolowo University, Ile-Ife 20-21 September, 2004. Aweto, A. (2002) “Outline Geography of Urhoboland”, Retrieved from http://www.waado.org/Geography/UrhoboGeography- Aweto.htm Delta state government (N. D) About Delta State, Retrieved from www.deltastate.gov.ng FAO (2007) “National Programmes for Food Security: FAO’s vision of a World without hunger. Rome IPCC (2007a) “Summary for Policymakers in: Climate Change 2007: Impacts and Adaptation and Vulnerability”, Contribution of Working group 11 to the forth Assessment Report of the Intergovernmental Panel on Climate Change: M.L. Parry et al (eds) Cambridge University Press, Cambridge, U.K. and New York, U.S.A. pp 7 – 22. Molua, E. L. and C. M. Lambi (2007) “The Economic Impact of Climate change on Agriculture in Cameroon”, World Bank development Research group (Sustainable Rural and Urban Development Team) Policy Research Working paper 4364 Washington D. C. National Population Census (NPC) (2006) Federal Republic of Nigeria, Federal Ministry of Women and Social Development, 2006. Online Nigeria (2003) Physical setting, Retrieved from http://www.onlinenigeria.com/links/Bayelsaadv.asp Schmidhuber J. and F. N. Tubiello (2007) “Global food security under climate change”, Proceedings of the National Academy of Science, Vol. 104(50), pp. 19703 – 08. http://www.onlinenigeria.com/links/Bayelsaadv.asp Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 209 Table 1: Socio-economic characteristics of Respondents Source: Field survey data, 2011 Table 2: Analysis of temperature record from 1971 – 2009 in Delta State Variable Coefficient Std. error t-statistic Prob. C 13.72317 4.721015 2.906826 0.0062 DT (-1) 0.564891 0.150065 3.764305 0.0006 Temperature Value Mean (0C) 31.49 Standard deviation (0C) 0.53 Maximum temperature (0C) 32.60 Minimum temperature (0C) 30.09 Trend coefficient (0C/year) 0.57 Coefficient of Variability (CV) 1.68 Source: NIMET and Author computed result, 2011 Variables Delta (n=410) Percentages (%) Age (Years) 30 – 39 91 22.2 40 – 49 163 39.8 50 – 59 132 32.2 60 – 69 24 5.8 70 – 79 0 Mean 48 years Gender Female 195 47.6 Male 215 52.4 Mode Male Marital Status Single 29 7.1 Married 267 65.1 Widow 60 14.6 Widower 6 13.2 Divorced 48 Educational Level Informal 126 30.7 Primary 157 38.3 Secondary 87 21.2 Tertiary 40 9.8 Mode Primary Household size 2 – 4 17 4.1 5 – 7 85 20.7 8 – 10 155 37.8 11 – 13 97 23.6 14 – 16 56 13.8 Mean (persons) 9 Annual Income(N) 21,000-60,000 304 74.1 61,000-100,000 100 24.4 101,000-140,000 6 1.5 141,000-180,000 0 181,000-220,000 0 221,000-260,000 0 Mean (N) 54,702 ($353) Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 210 Table 3: Analysis of Rainfall Data from 1971 – 2009 in Delta State Variable Coefficient Std. error t-statistic Prob. C 37.41685 8.522643 0.0000 DR (-1) - 0.376412 0.159985 - 2.352793 0.0242 Rainfall Value Mean (mm) 231.41 Standard deviation (mm) 27.31 Maximum rainfall (mm) 283.05 Minimum rainfall (mm) 189.02 Trend coefficient (mm/ year) - 0.38 Coefficient of Variability (CV) 11.80 Sources: NIMET and Author computed result, 2011 Table 4: Predicted future values of climate Change Factors in Delta State Year 2015 2020 2025 2030 2035 2040 2045 2050 Temperature (0C) 32.25 32.40 32.56 32.71 32.87 32.03 33.18 33.34 Rainfall (mm) 243.38 246.19 249.02 257.89 254.79 257.72 260.69 263.69 Source: Author computed projected values, 2011 30.0 30.5 31.0 31.5 32.0 32.5 33.0 1975 1980 1985 1990 1995 2000 2005 DT Figure 1: Trend of Temperature Data for Delta State (1971 – 2009) Figure 1 reveals an increasing trend of temperature in Delta State DT = 13.72 + 0.56T Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 211 180 200 220 240 260 280 300 1975 1980 1985 1990 1995 2000 2005 DR Figure 2: Trend of Rainfall Data for Delta State (1971 – 2009) Actual Fits Forecasts Actual Fits Forecasts 205020402030202020102000199019801971 33 32 31 30 T e m p e ra tu re ( 0 F ) Year Yt = 30.8847*(1.00096**t) MSD: MAD: MAPE: 0.154162 0.272218 0.868231 Delta Temperature Growth Curve Model Figure 3: Predicted Future Values of Temperature (Delta State) DR = 318.89 – 0.376412T Asian Journal of Agriculture and Rural Development, 2(2), pp. 206-212 212 Actual Fits Forecasts Actual Fits Forecasts 205020402030202020102000199019801971 280 260 240 220 200 (m m ) R a in fa ll Year Yt = 219.552*(1.00229**t) MSD: MAD: MAPE: 668.403 21.939 9.595 Delta Rainfall Growth Curve Model Figure 4: Predicted Future Values of Rainfall in Delta State