Some aspects of the climate of north-western Nigeria were examined in this study, focusing more on rainfall, its inter-and intra-annual variability and patterns of distribution. Adopting the statistical distributions commonly used to describe climate states such as the mean, the standard deviation and the coefficient of variability, the climate of north-western Nigeria was analyzed for possible shifts in mean conditions and patterns. The study found that climatic conditions in north-western Nigeria have altered substantially as four drought episodes took place within the last three decades of the 20 th Century and, the 1984 drought-year rainfall was 58.8 percent lower than the long-term mean rainfall. The study further showed that the 1968 to 2008 mean rainfall shifted downwards by 8.8 percent from the long-term mean, although it cannot be said if the shift is permanent or temporary since recent rainfall trends tend to suggest a recovery. Possible options for stabilizing the regional climate are suggested.

This study examined the role of gas flaring in the rapid corrosion of zinc roofs in the Niger Delta Region of Nigeria. Four experimental sites were set up where samples of galvanized iron sheet (popularly called ''zinc roofs'') were exposed to the atmosphere. The corrosion behaviour of galvanized iron sheet through weight loss determination under different environmental conditions was monitored. A uniform angle of inclination of 22°( which represents the mean angle of inclination of house roofs in the study area) was chosen. The results showed that corrosion was more severe (average readings of 25.89, 34.30, and 21.27 mg) in the three experimental sites that were located near pollution sources such as gas flare station or sea aerosols, than at the controlled site (2.36 mg) that was located far away from pollution sources. It is recommended that government's policy of zero gas flaring for oil companies operating in the Niger Delta by 2010 be pursued with vigour, so as to realize the deadline and subsequently reduce the economic burden currently suffered by the inhabitants of the Niger Delta through frequent replacement of house roofs and incessant illnesses. In addition, individuals and companies operating in the region should avoid bush burning, reduce the rate of fossil fuel consumption by conserving energy, and install catalytic converters in cars and industrial chimneys, so as to reduce emissions.

This paper considered the phenomenon of climate change in relation to frequent and intensified flood problems in Uyo, the Capital City of Akwa Ibom State, Nigeria. Empirical evidence on the onset of climate change in Nigeria was presented. Flood problems worldwide were highlighted, together with their impacts in terms of deaths, economic losses and associated human sufferings. To this end, a detailed rainfall analysis was conducted for the study area, Uyo, using statistical distributions commonly deployed to describe climate states, such as the mean, the running mean, the standard deviation, coefficient of variability, skewness, and kurtosis, as well as, parametric statistics such as Kruskal-Wallis test and ANOVA. Results showed that recent rainfall amounts and patterns in Uyo were out of step with long-term mean conditions. For instance the 2005-2014 mean rainfall was 22% above the 30-year mean from 1985 to 2014. The rainfall Skewness and Kurtosis showed significant swings in the central tendency and confirmed the establishment of a new mean and a new standard deviation in the 2005-2014 decade. These trends were further confirmed to be statistically significant by Post Hoc Test at the 0.05 level. The implication of these findings is that rainfall is adding more water to surface runoff, leading to incessant, severe flood conditions. Although some effort has been made to reduce the incidence of flooding in Uyo through the provision of drains and storm sewers (pipe-jacking), a lot more needs to be done in terms of provision of infiltration surfaces (green areas) through sustainable urban renewal programme. Climate change mitigation options such as reducing gas flaring, bush burning, and fossil fuel combustion are recommended.

Irregular rainfall is the primary reason for severe crop yield reductions in the Sahel of West Africa, with sometimes very serious consequences for society and national economies. To that extent recent drought events in the Sahel have overprinted their rhythms, causing widespread dislocation to human beings and their economic activities. Accordingly, this study provides a procedure for predicting future crop yield trends using scenarios of climatic events. In the process, models which relate rainfall to agricultural yields were constructed for three sites in Northern Nigeria. The models were constructed for a 17-year period spanning 1969-1985, the severe drought years. In all cases, the model input variables were rainfall and crop yield data. All the models were tested for their predictive capabilities using crop yield data for 1986-2006. In order to assess the potential effects of drought on agricultural yields in the West African Sahel, the study created scenarios of future climatic changes based on arbitrary data and analogues of historical climatic data. The results indicated that a possible climatic change which involves up to 50% reduction in the mean rainfall for locations in the West African Sahel will reduce yields substantially and in many cases could lead to total crop failure. The study concludes that scenario experiments are useful tools in guiding farmers on adjustment options during drought events. Additionally, supplementary irrigation schemes must be pursued vigorously by all stakeholders if farming is to remain lucrative in the region.

The impact of climatic variations on crop yields and the adaptation by farmers in north-western Nigeria are examined using the modeling approach and farm surveys. Accordingly, regression models which relate climate data to crop yields were constructed. The results showed that rainfall has a positive relationship with crop yields in the region and explained over 70 percent of the variations in the yields of sorghum, millet and maize, all of which were significant at the 0.05 level. Evaporation also had a significant but inverse relationship with crop yields. Other climatic elements in the experiment provided minimal levels of explanation. The farm surveys found that rural farmers in north-western Nigeria were quite innovative when it comes to adapting to drought. The study concluded that the impact of climatic variations on crop yields in north-western Nigeria can be substantial especially under drought conditions. The need to update farmers' adaptive strategies is emphasized. Keywords: Northern Nigeria, Climate change, Drought, Crop-climate models, Farm surveys, Adaptation strategies 1. Introduction Farming in northern Nigeria is predominantly rural, with over 80 percent of the farmers practicing rain-fed, subsistence agriculture. These peasant farmers produce for subsistence rather than for sale. Thus the aim of food crop production is not to maximize profit but to feed one's family. In the process of meeting family nutritional needs, surplus agricultural products are however disposed in the local markets for money. Climate plays an important role in the agricultural productivity of many parts of northern Nigeria and, with very low level of technology and rigid adherence to traditional ways of farming, recent variations in the weather and climate of the region have taken severe toll on crop production. Indeed, crop production in many parts of northern Nigeria is frequently seen as a matter of lottery since rainfall varies substantially both in time and space, and the variability largely determines the yields and productivity of crops in the area. Since the early 1970's, drought has affected many parts of northern Nigeria with agricultural outputs varying widely from year to year and from one location to the other. The constraints posed by climate change on agriculture in this region range from pronounced seasonality of rainfall (which confines cultivation to short periods of three to five months) to severe and recurrent droughts (which disrupt the usual pattern of seasonal water availability). Most of the droughts also exhibit such characteristics as false onset of the rains, late onset of the rains, pronounced breaks during the rainy season, and early cessation of the rains; leading to drastic alterations in the pattern of seasonal rainfall distribution (Adefolalu, 1986;Anyadike, 1993;Aondover et al., 1998; Ekpoh, 1999a;Dai et al., 2004; Anyanwole, 2007). These are very important climatic limitations placed on crop production in the region because it makes the correct timing of farm operations (which i...