**1. Introduction**

Climate change is a real phenomenon worldwide [1] as observed in the increase in atmospheric and oceanic temperature, decreased amounts of snow and ice as well as a rise in sea level [2]. The earth's surface has been warmer in past three successive decades [2] resulting higher average temperature compared to the past centuries. The term "climate change" is defined differently among different stakeholders even though the contents are similar in context. IPCC [3] defines climate change as a change in the state of the climate that can be identified by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Based on the United Nations Framework Convention on Climate Change (UNFCCC), climate change refers to a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time periods [3].

Impacts of climate change vary depending on the state of development of a region. For example, IPCC [4] suggest that rising temperatures and changing precipitation rates will most likely hamper success of rain-fed agriculture in most developing countries. Africa is one of the continents that is projected to experience rising temperatures of at least 1 to 2°C and higher likelihood of extreme weather [5, 6]. Thus, the effects of climate change will more directly affect agriculture because about three-quarters of Africa's population depends on agriculture for a livelihood and Africa's agriculture is mainly rain-fed [7–11].

For sub-Saharan Africa (SSA), agriculture largely contributes to employment of the majority of the people in rural areas and significantly to the Gross Domestic Product (GDP) of most countries. Thus, a large number of people in SSA is employed in agriculture and increasing agricultural productivity is necessary to reducing poverty and food insecurity (AGRA [12]). However, the rise in temperatures and increased stochastic rainfall variations have both direct and indirect grave consequences on crop yields and agricultural productivity. While agriculture is so important to most developing economies in SSA, most agricultural sectors in SSA have performed poorly relative to other developing world regions [8]. Kotir [7] contends that over the past 50 years, agricultural productivity has been steadily declining in SSA and recorded the slowest increase across the world over and that this would only get worse with climate change. Taken together, this evidence suggests production of maize, a vital crop for many millions in SSA [13] may have its production in danger in the face of climate change.

Maize, a field crop that is one of the most cultivated crops in the world, is a staple crop for most countries in SSA [13]. While maize remains an important crop for many millions in SSA, its yields in developing countries (including SSA) are lower than in developed countries [14–16]. More importantly, maize production depends on water availability, and most of SSA's agriculture is rain-fed, which makes maize production an obvious candidate to be affected by weather shocks such as droughts—one of the negative consequences of climate change. Lobell et al. [17] suggest maize is sensitive to daytime high temperatures above 30°C and with climate change, the projected 2°C in temperatures for most parts of Africa would affect maize production, which would further lower maize productivity levels in SSA despite the increasing demand for maize.

Because climate change impacts are seemingly being felt, numerous studies have examined impacts of climate change on maize production and productivity resulting in several adaption strategies being promoted to negate the negative effects of climate change (e.g., [5, 14, 18–21]). To the best of our knowledge, there has not been any studies in literature that provide a comprehensive review of impacts of climate change on maize production and productivity in SSA. This chapter therefore provides a detailed review of climate change impacts on maize production and its productivity in SSA. We chose SSA because as mentioned earlier, most countries in SSA are underdeveloped and their agriculture is rain-fed—making them more vulnerable to climate change effects. This is important because this review will provide an easier access of such results for both scholars and policy makers that are in search of empirical impacts of climate change on maize production and productivity for relevant policy.

This rest of the chapter is organized as follows. The next section provides the main literature review of studies that have examined climate change impacts on maize production and productivity specifically in SSA. Adaptation to climate change as well as relative importance of temperature and rainfall are also discussed.
