Alex Rose-Innes
Research shows that garbage decomposition across sub-Saharan Africa (SSA) dumpsites can cause billions of dollars damage to the environment, or, if harnessed as clean energy, can generate an income of US$6.7 billion by 2060.
African sustainability scientist and author of the research, Nkweauseh Reginald Longfor from Cameroon is a PhD candidate at Sophia University in Bulgaria. During his research, he has established that 95% of waste dumps across 44 SSA countries are unregulated. These landfill sites continue taking in new garbage even when filled to capacity, with the decomposing waste releasing tremendous amounts of harmful greenhouse gases.
Globally, about 70% of municipal solid waste ends up in landfills or unregulated dumpsites. Across SSA, only 24% reaches landfills while the rest is disposed of in open dumps, streets, rivers and other unsuitable locations.
Health and Economic Damage
“We live in a society where waste is disposed of without considering the cost to either consumer or producer. Waste decomposing in landfills releases greenhouse gases and these gases, (carbon dioxide, nitrates and hydrogen sulphides), can harm people’s health, either by polluting the air we breathe or contaminating nearby water sources,” Longfor said.
His research argues that this causes economic damage. To determine this economic damage, Longfor and colleagues compared the ongoing costs of poor waste management in the 44 SSA countries between now and 2060 with the costs of better waste management practices such as sanitary landfills and anaerobic digestion.
Anaerobic digestion is a natural process using a sealed container in which micro-organisms such as bacteria convert organic waste into biogas. The most energy-rich component of biogas is methane, makes up 50–75% of its content, depending on waste type and operating conditions.
Anaerobic digestion also converts organic waste into digestate, organic fertiliser useful for gardening or farming. Cities in Europe have used anaerobic digestion to convert organic matter found in municipal solid waste into electricity, cooking gas and heat for the past 20 years.
Sanitary landfills are municipal dumps where wells and pipes collect landfill gas, about 50% methane and 50% carbon dioxide, with a few other compounds. This gas can be used to generate electricity, to fuel boilers or processed for use in vehicles. Sanitary landfills are also designed to prevent pollutants from escaping into the air, soil, or groundwater. To be effective, they need to be properly located, built, maintained and operated.
Illustration courtesy of Resources, Conservation & Recycling Advances journal, 20 (2023)
How Landfill Gas can be Converted
By capturing methane, a highly harmful greenhouse gas and converting it into energy, its release into the atmosphere is decreased, lessening the effects of climate change. This in turn, reduces the economic costs of problems such as habitat loss, property damage, disease spread and soil and water contamination. Also, the long terms deadly effects of methane are lessened. According to Longfor, the research showed that the cost of installing sanitary landfill and anaerobic digestion technologies to convert waste into energy is but fraction of the economic damage caused by methane emissions. These green technologies are cost-effective solutions for tackling the high health and economic costs of climate damage.
Secondly, methane contained in organic waste can be a renewable energy source, helping to decrease the reliance on fossil fuels. This would mean lower energy costs, more energy security and less environmental and economic damage from fossil fuel use.
According to this latest research, by 2060, SSA countries could generate between 20 and 58 million MWh of electricity just from waste. This could provide each African with an extra 100–230 kWh of electricity. From 2035 to 2060, the top twenty countries could produce between 0.2 and 3.3 million MWh to 0.4 and 8.5 million MWh of electricity from waste.
The damage caused by these emissions – one kilogram of methane emissions is costing, on average, US$1.943. If Africa continues to dispose of solid waste as the same way it is done now, the economic damage from methane emissions could reach billions of dollars. This cost seems to double every decade from 2025 to 2060.
While all SSA countries are likely to experience some damage, certain countries could face costs running into billions of dollars. For example, by 2060, Ethiopia, Nigeria, the Democratic Republic of Congo, South Africa and Tanzania could accumulate economic damages amounting to US$6.7 billion, US$4.5 billion, US$4.7 billion, US$2.7 billion and US$3.2 billion, respectively.
African countries most at risk
Angola, Mauritius and Cape Verde rely heavily on landfills for waste management. Their landfills are 70%, 90%, and 91% full respectively. These countries are most at risk. The estimated economic damage to Angola will rise from US$153 million in 2012 to a projected US$1.7 billion in 2060 because of their reliance on landfills.
Countries with growing populations and economies – Ethiopia, Nigeria, the Democratic Republic of Congo, South Africa, Tanzania, Madagascar, Mozambique and Uganda – could face economic losses exceeding US$2 billion each by 2060 if they do not clean up their landfill practices.
All African countries should introduce waste reduction, reuse, recycling and energy recovery, promoting public health, reducing greenhouse gases and supporting a green, circular economy. SSA countries should also adopt policies promoting private investment in the kind of clean waste management that leads to economic, social and environmental benefits, Longfor advises.