**1. Introduction**

Renewable energy remains the most dominant energy source in Africa with wood sources accounting for a large share of biomass energy. Although wood energy accounts for only 10% of global primary energy, about 2.8 million people depend on wood fuel for cooking and heating [1, 2]. The extraction and use of wood for energy is prominent in developing countries with more than 70% of households in Sub-Saharan Africa depending on wood energy. Access to modern energy remains a major problem in developing countries; however, poorer countries suffer more from energy access problems [3]. Poor access to modern energy rates in less developed countries (LDCs) and Sub-Saharan (SSA) countries remain high at 91

and 83%, respectively. In SSA, the access to electricity and modern energy remains a major constraint with 560 and 625 peopled deprived, respectively. Poor access to modern energy equally varies between urban and rural areas in Africa; in SSA, 66% of the population use solid fuels for heating and cooking, 13% use charcoal while kerosene, electricity and LPG follow with 7, 6, and 5%, respectively [4].

The global use of wood fuel for cooking and heating has devastating negative health effects with 2 million deaths annually from pneumonia, cancer and chronic lung diseases due to exposure to pollution from biomass combustion. Women and children are most affected by these diseases with about 44% of these deaths being children and 60% of adult death being women [3]. More than 50% of deaths from pneumonia, cancer and chronic lung diseases in LDCs and SSA is due to combustion of solid fuels, while only 38% for developing countries in general [3]. Household air pollution (HAP) is a major driver of global health emergencies with about 4.3 million premature deaths; non-communicable diseases (NCDs) account for 3.8 million deaths (WHO, 2016). HAP accounts for more than 33% deaths related to chronic obstructive pulmonary in both low- and middle-income countries, 17% of deaths related to cancer, 15% of ischaemic heart disease and 25% stroke-related deaths (WHO, 2016). This chapter seeks to review the different diseases caused by incomplete combustion of biomass for energy and how bioenergy from tree commodities can be a sustainable remedy.
