Fossil energy released when coal, oil and natural gas are transformed into their oxidised state—carbon dioxide (CO2)—has driven mobility, electrification, industry and innovation—the bricks of the modern economy. Two centuries of scientific discovery have revealed the potency of certain gases, including CO2, to enhance the atmosphere’s natural “greenhouse effect”, which maintains elevated surface temperatures relative to a planet without an atmosphere. Since the British Industrial Revolution, there has been significant increase in the abundance of carbon dioxide (from fossil fuel use), methane (from livestock production) and nitrous oxide (from agricultural intensification) released to the atmosphere. These so-called greenhouse gases (GHGs) have resulted in a rise in global temperatures at a rate unseen in past geological eras.
As temperature influences natural forces (winds, ocean currents, precipitation patterns, etc.), global warming has led to climate change. Scientific literature has repeatedly suggested that climate change will result in more frequent extreme weather events (floods, droughts, heat waves, etc.), melting of polar ice caps and changes in crop yields and productivity, some of which are already evident today, and all of which will disrupt the current socioeconomic order. The fossil fuels that have spurred global economic growth for centuries now threaten to be its inhibitor.
Increasing mainstream acceptance of climate change and its devastating consequences, should unmitigated greenhouse gas emissions continue, has galvanised political action. Most recently, there has been a global treaty—the Paris Agreement—to limit temperature rise to “well below 2°C relative to pre-industrial levels” by the end of the century. A debate on the path to Paris and the feasibility/usefulness of the agreement itself has since ensued. It is now widely accepted that mitigation and adaptation measures are necessary to address climate change effects.
Adaptation is the adjustment of the natural and built environment, and human behaviour to reduce their vulnerability to climate change impacts e.g. flood defences against sea level rise, reduced meat consumption to curb agricultural emissions. Mitigation is the prevention of further climate change by reducing the sources or enhancing the sinks of greenhouse gas emissions e.g. switching from using fossil fuels to renewable energy; this process is often referred to as decarbonization.
To achieve the Paris accord target, net emissions must fall to zero (i.e. complete decarbonization) by 2070; this requires an unprecedented transition of the global energy system so as to decouple economic growth and rising GHG emissions from fossil fuel use. Studies have consistently concluded that the least-cost pathway to achieving this requires the extensive deployment of a range of clean energy technologies including renewable energy (solar, wind, nuclear and hydro power), energy storage (large-scale batteries) and carbon capture and storage (CCS)[1]; CCS is a technology that prevents emissions from fossil fuel combustion from being released to the atmosphere by capturing them in a fluid and storing them in geological formations underground. Improved energy efficiency across all sectors of the economy, reduced energy demand growth and divestment from fossil fuels are also critical. Whilst these decarbonization measures can, and are being pursued, at some cost, in industrialised economies, they will prove difficult in emerging economies—the centres of future population and economic growth—where near-term industrialization objectives will compete with long-term mitigation strategies for investment.
Nigeria is projected to contribute 10 per cent of the 2.2 billion increase in global population expected by 2050.[2] Nigeria’s burgeoning population and tropical climate—where temperature is expected to increase faster than the global average—leave its local ecosystems vulnerable to climate change. These ecosystems provide direct and indirect services to the population, including nutrient cycling to maintain the fertility of soils, waste decomposition, and pest and disease control. The dependence on oil rents for 90 per cent of export revenues also leave the economy vulnerable to climate policies that seek to wean the world off fossil fuels. The policies that the government implements in the coming years will determine Nigeria’s competitiveness in an increasingly carbon-constrained world.
The most recent estimates show that Nigeria is responsible for 490 metric tonnes of GHG emissions (CO2 equivalent) annually, just over 1 per cent of global production. 39 per cent of this arises from land-use change and forestry; 33 per cent from energy production (oil and gas extraction, and the power sector); 14 per cent from waste (incineration of municipal waste); 13 per cent from agriculture; and 2 per cent from industry. As a party to the Paris Agreement, Nigeria has committed to reducing its GHG emissions by 20 per cent relative to a business-as-usual scenario of economic and emissions growth by 2030, and to pursuing a 45 per cent reduction if sufficient international support is received.[3] It intends to achieve this by ending gas flaring (burning of excess gas from oil and gas production), increasing the use of renewable energy, implementing climate-smart agriculture and championing reforestation efforts.
Whilst these are positive objectives, there is little evidence to suggest that they are being pursued with enough momentum to meet these targets. Encouraging the intensification of agriculture, increased industrialization and rising oil production, instead, appear to be the focus of government efforts. Each of these sectors—agriculture, industry and energy—is vulnerable to climate change and/or climate policy, so it is important to assess how global trends in each are likely to manifest locally and how the emerging challenges can be mitigated against in the long-term.
Fossil Fuels in a Carbon-constrained World
In 2016, Nigeria experienced its first recession in a decade due to low oil prices. With 70 per cent of government revenues generated from oil and gas exports, the plummeting of oil prices from 100 to 30 dollars per barrel resulted in a scarcity of foreign exchange, and the country could not satisfy its hefty import bill. The plummeting of crude oil prices began in June 2014 due to a number of factors: weak economic activity in the biggest oil-consuming nation led to weak demand growth; rising production from Iran and the US due to the lifting of economic sanctions and an emerging shale industry, respectively, led to oversupply; and a refusal by a stubborn OPEC (read “Saudi Arabia”) to cut production to avoid losing market share and lifting prices, both of which would have benefited emerging producers (read “enemies”)—Iran and US shale companies.
The strategy failed due to a characteristic American resilience that saw the shale industry survive many bankruptcies (that occurred as a result of low oil prices) by harnessing technological innovation in fracking. Fracking is the horizontal drilling method used to release oil and gas in shale rock formations, and enabled US shale companies to reduce production costs and increase production volumes. OPEC has since ceded and, with Russia, has agreed a prolonged period of production cuts to recover oil prices to the levels we observe today (~$70/barrel). How long this pact will last is anyone’s guess, however the tumultuous period preceding it has ushered in a new era for the oil industry that may prove detrimental to the Nigerian economy.
The shale revolution is set to make the US the largest oil producer by the end of 2018, surpassing Russia and Saudi Arabia, a prospect that will affect global oil markets and geopolitics. Increasing climate change concerns are pushing governments to encourage improved energy efficiency and switching from internal combustion engines to electric vehicles (EVs) so as to reduce fossil fuel use; several countries including the UK and France have now imposed a ban on fossil fuel car sales from 2040. Several forecasts suggest that the effect of EVs on oil demand will be minimal because other crude oil-reliant sectors including marine transport, heavy goods vehicles (HGVs), aviation and petrochemicals, which are driving demand growth are yet to have alternative fuel sources.
Electrification of HGVs and even shipping is, however, being developed. The resulting downward pressures on oil demand (from alternative energy sources) and prices (from US shale) may be signalling that a period of peak demand is approaching. This was the subject of a paper by Bassam Fattouh (Director, Oxford Institute of Energy Studies) and Spencer Dale (Chief Economist, BP). They highlighted that a paradigm shift is occurring in the oil markets “from an age of scarcity (or, more accurately, ‘perceived’ scarcity) to an age of abundance, with potentially profound implications for global oil markets as they become increasingly competitive”.[4] This predicted long-term decline of oil prices is fuelling the pursuit of ambitious economic diversification reform by oil-dependent economies in the Gulf (UAE Vision 2021, Saudi Arabia Vision 2030, Aramco IPO, etc.). The success of these reforms will signal when the oil price no longer dictates the ability of these countries to balance their budgets and fund government operations. The rationing of production that maintains an artificially high price will likely stop and prices will fall. Even before that, OPEC could lose its ability to exercise market power as a result of increasing production from outside of the cartel. Should Nigeria lag in diversifying its revenue base, it will again have to contend with low oil prices but this time without the prospect of price recovery to ease economic decline.
Power and Industry
History suggests that industrialization is essential for economic development. Industry is also a means to economic diversification that can boost employment opportunities for relatively unskilled labour, however this approach is yet to be constructively pursued in Nigeria. The GHG emissions inventory serves as a good indicator of the lack of industrial activity, with the sector producing just 10 MtCO2 annually. By comparison, Africa’s other leading economies—South Africa, Egypt and Algeria—produce 22, 16, and 28 MtCO2, respectively.
A lack of reliable and affordable electricity supply has been a hindrance to industrialization, albeit one of many.[5] Businesses often rely on private diesel generators for expensive power, which cuts into competitiveness. A rehabilitation of Nigeria’s ailing power sector will improve energy access while reducing costs for consumers. It also presents an opportunity to alleviate climate change and health risks due from toxic emissions from diesel use, as they can be potent GHGs (e.g. NOx) and/or carcinogenic. Government has sought to improve the efficiency of the energy sector through privatization of power generation and distribution assets, which began in 2008. The resulting independent power producers (IPPs) often invest in natural gas-fired generation due to the domestic abundance of the resource and relatively low capital costs of gas power plants.
About 11 gigawatts (GW) of gas capacity currently provide 82 per cent of power supply (with hydro providing the rest) and comprise 79 per cent of the 23 GW of planned power projects (African Energy Live Data, 2018).[6] Note that not all of online gas capacity is operational due to transmission, gas or water availability constraints. This approach has positive and negative impacts on climate change. Increased gas generation allows for currently flared gas, which has the potential to produce up to 2.5 GW (Fidelis, 2018), to be utilised, consequently reducing emissions from oil and gas extraction. However, it is often overlooked that per capita income and per capita energy demand are positively correlated, so economic growth will bring an exponential rise in energy demand. A gas-centric power generation expansion will nullify and surpass avoided flaring emissions by shifting them to the power sector. This will also centralise air pollution, previously from diesel, in gas generation sites predominantly in the southern parts of the country.
The above is not suggesting that natural gas use should be avoided; it is an attractive near-term option for improved energy supply and produces significant less air contamination than electricity production from coal or diesel. However, short-termism in planning risks locking Nigeria into a scenario where significant emissions from gas cannot be mitigated until the decades-long lifetimes of these plants are reached. This will leave Nigeria vulnerable to stricter climate policies, which are likely if the world is not able to decarbonise quickly enough to meet the Paris target. Furthermore, in a world where stranded assets—investments that are unable to earn a return as a result of changes associated with the transition to a low-carbon economy—are becoming a reality, it will be economically unwise to invest heavily in gas when the rapidly declining costs of renewable energy technologies are making them increasingly competitive. When the negative externalities of prolonged fossil fuel extraction and use—spillage, air pollution, climate change etc.—are considered, renewables prove cheaper and thus should be the focus of future power system expansion.
The Rise of Renewables
The renewable energy industry has enjoyed significant government support in the form of favourable policies or subsidies (feed-in tariffs, curtailment payments, contracts-for-difference schemes etc.) in many countries due to the government’s efforts to decarbonise the economy. These incentives have spurred technological innovation and made cheaper financing accessible for developers; both of which are responsible for the rapidly declining costs of wind turbines and solar panels. A study by Bloomberg New Energy Finance showed that solar power is now the cheapest form of new electricity in 58 countries, including Nigeria.[7] By the mid-2020s, unsubsidised utility-scale renewable electricity is expected to be competitive with fossil fuel-derived electricity. The changing economics of renewable energy present an opportunity to develop a low-carbon energy supply, which can power homes and industry without ballooning GHG emissions and stifling climate change mitigation efforts.
This potential has been recognised in Nigeria, and government and multilateral organizations are funding an increasing number of renewable energy projects, mostly off-grid generation. Off-grids (sometimes called mini-grids) are small-scale power generation and distribution systems that can supply isolated settlements. Using off-grids powered by solar or hydro power has three major limitations for sustainable climate change mitigation. First, they can typically only provide kilowatt-scale power, which is sufficient to power household appliances such as televisions and lighting. For the rural communities that these systems often serve, this limits their ability to operate large energy-consuming appliances e.g. industrial equipment; hence, economic pursuits are restricted.
Secondly, although some GHG emissions are avoided by off-grids, the energy demand centres (densely-populated urban or industrial towns) are often grid-connected and greater mitigation can be achieved by decarbonising their power supply. Lastly, off-grids’ potential to improve energy access is less than that of on-grid renewables, as the latter benefit from existing transmission infrastructure and economies of scale. Research by CrossBoundary has shown that while off-grids are the cheapest option to provide 99 million Africans with energy due to sparsely distributed population, grid extension is the cheapest option for 212 million people. Therefore, even though they have a role to play in achieving rural electrification, solutions proposing off-grids as a panacea for all energy-related climate change mitigation should be viewed with caution.
Despite the vast potential of on-grid renewables for decarbonization, investment is lacking due to the high upfront costs of the technologies and the difficulty to access cheap financing in Nigeria. 14 utility-scale solar IPPs that would have contributed 1/13 GW of our renewable capacity target by 2030 have recently been rejected by the Ministry of Power on cost grounds, citing lower costs in East Africa and urging developers to scale-down projects. Risk premiums however will remain high until such projects are successfully demonstrated; pursuing smaller scale on- or off-grid solutions will delay this and deter GHG emissions reductions. The near-term focus should be on driving down costs of projects through favourable legislation.
The 2016 feed-in tariff that obliges distribution companies to source 50 per cent of their electricity from renewable sources is a positive development, but the recent 5-10 per cent import duty imposed on solar panels threaten on- and off-grids projects alike. Policies that prioritise the dispatch of renewable electricity to the grid, redirect current fossil fuel subsidies to renewables, and/or compensate for incidences when variables renewables are curtailed will help to ensure that operators generate stable revenues and therefore encourage investment. Curtailment occurs when a reduction of output from solar and wind power is mandated (often by the grid operator) due to low demand or transmission issues. As subsidies are only being channelled from fossil fuels to renewables, the additional cost incurred by government will be minimised, so budgetary constraints are not exacerbated. The political expediency of such reforms, however, remain a key barrier that must be addressed. Consistency in energy, climate and trade policy is needed to allow for the establishment of a renewable energy industry that can be the foundation of a low-carbon economy, which will help Nigeria meet its commitments to the Paris Agreement.
It is worth noting that the intermittency of solar and wind power is often highlighted as a limitation to their widespread adoption. However, Nigeria enjoys some of the highest capacity factors for solar photovoltaics in the world, so intermittency issues are minimal. Furthermore, gas generation can provide flexible back-up capacity and pumped hydroelectric power, which is abundant, can provide energy storage services during periods of low solar insolation. Battery costs are prohibitive, but they are falling; this makes them an attractive long-term option for energy storage that compensates for the variability of supply that renewables suffer.
Agriculture and Forestry
Land-use change (LUC) and agriculture are responsible for 25 per cent of global GHG emissions: 11 per cent from land-use change and 14 per cent from livestock. LUC emissions arise from changing carbon (plant matter) stocks above and below ground when land is converted from one purpose to another e.g. forestland to agricultural land, or a switch from corn production to soybean production. Agricultural emissions are contributed by methane released from the guts of ruminants (cattle, sheep and goats), nitrous oxide gases from fertiliser use, and carbon dioxide from fuel use in heavy agricultural machinery. Although methane and nitrous oxide are emitted in smaller quantities than carbon dioxide from fossil fuel use, they have global warming potentials that 25 and 300 times greater, respectively.
In Nigeria, land-use emissions account for 52 per cent of our GHG production. This is largely contributed by the clearing of forestland for firewood and wood charcoal, agriculture and commercial logging. Satellite data has revealed that between 1987 and 2011, lowland, mangrove and freshwater forest area in the Niger Delta has decreased by 15-40 per cent due to human activity.[8] The GHG emissions that resulted have been accompanied by significant loss in biodiversity and the ecosystem services they offer, both of which exacerbate global warming.
The associated health risks of wood use are equally devastating. Burning wood in open fires in enclosed spaces, as is common practice in rural areas in Nigeria, produces carbon monoxide and soot, which are air contaminants; long-term exposure to these pollutants has been linked to a range of respiratory diseases including bronchitis. Nigeria experiences the greatest number of air pollution-related deaths in Africa. Addressing our land-use derived emissions will help to alleviate climate change and imminent health challenges. Domestic wood demand can be drastically reduced by the electrification of firewood-dependent communities with clean energy so electric stoves can be used for cooking. This will prove unfeasible in the short-term due to the large investment in energy infrastructure needed to satisfy sparsely distributed rural communities. A switch to stoves using liquefied petroleum gas (LPG), which produces less harmful emissions, is a viable alternative in the meantime; efforts should be directed at making the fuel affordable for low-income households.
Most importantly, government must follow-up its reforestation commitments with action, especially in coastal regions that are expected to experience sea-level rises and increasing incidences of erosion. Forest cover will add resilience to the surrounding environment by reducing run-off effects; they will also enhance carbon sinks, as trees absorb significant quantities of carbon dioxide during their growth. In the north, tree cover can deter the encroachment of the Sahara. From 2005-2015, state governments provided virtually no patronage to forestry services (Akpan-Ebe, 2017).[9] Re-establishing forestry reserve quotas for states will oblige them to channel resources and improve conservation practices.
Recent governments have repeatedly stated their commitment to reclaiming Nigeria’s historical status as an agricultural powerhouse. There are several pitfalls of advancing “big ag” without understanding the positive feedback between climate change impacts and altering local ecosystems. The intensification of agriculture, particularly livestock production, has contributed significantly to the global warming experienced to date. Successful mitigation of emissions from this sector would require a major change in diet choices; adopting a plant-based diet is considered critical to reducing the demand for meat and hence the associated GHG emissions from its production. As meat is a fixture of indigenous cuisines and making a cultural change will prove difficult, if at all possible. Furthermore, an increasing population requires the continued commercialization of agriculture. Adapting agricultural practices to climate change impacts should therefore be the focus of efforts.
Climate change is increasing the frequency of droughts and changed precipitation patterns, both of which have exacerbated heat and water stresses, especially in the arid north of the country. The shrinking of the Lake Chad basin is indicative of climate change’s footprint in the Sahel. A nature study has shown that the rainforests, savannahs and woodlands of sub-Saharan Africa have lost around 2.6bn tonnes of CO2 over the past seven years due to droughts, wildfires and deforestation, with Nigeria experiencing some of the greatest losses.[10] Aridification is pushing the North’s nomadic herders southwards into the fertile middle Belt to find suitable pastures for their livestock. Clashes between cattle rearers and farmers whose lands have been encroached on have resulted and created a security crisis that has led to extensive loss of lives and property.
However, in the future, climate-driven migration will not be limited to livestock farmers. Already, people in the parts of Borno and Yobe states at the fringes of the Sahel have to travel kilometres at a time to find water. As these areas become increasingly arid and inhabitable, communities will migrate for survival and create new planning, health and security challenges in the settlements to which they move. The expected reduction in precipitation around coastal areas will lower yields of cash crops such as cocoa and coffee that require lengthy rainy seasons. Declining yields of cereals are also expected. With the exception of rice, all main crops—sorghum, maize, cassava, millet and soybeans—are projected to experience yield decreases of 5-40 per cent by 2050 if no technological innovation in farming methods is implemented.[11]’[12]
Crop productivity is also expected to fall, so more water and fertiliser inputs will be needed to achieve a given output. Consequently, the costs of crop production will rise and affect competitiveness of local agricultural products in international markets. With 70 per cent of Nigeria’s population engaged in agriculture, the socioeconomic repercussions cannot be overstated.
Challenges faced by farmers require a shift from the current practices. Farmers’ reliance on rain-fed agriculture has meant that irrigation methods are poorly established, and there are no methods to counter the poor harvests resulting from decreasing precipitation. Small-scale irrigation schemes must be implemented to allow for sustainable crop production. These schemes are not infrastructure-intensive but are challenging, as they require dissemination of knowledge about climate change and its impact on local agro-ecological systems to small-scale farmers (80 per cent of farmers) who are autonomous.
The Food and Agricultural Organization (FAO) of the UN have, nonetheless, piloted such awareness campaigns in neighbouring Sahelian countries. It is for government to establish knowledge-sharing partnerships that will allow local farmers to benefit from the existing expertise on climate-smart agriculture. The relevant fields of study that can be leveraged to solve climate change issues should be emphasised in curricula so local expertise can be nurtured. With regards to desertification and drought, funding must be channelled into the research of genomes that can enhance drought-resistance in cereals and improve the affordability of bioengineered cereals that allow for sustained crop yields in harsher climes.
Such genome engineering is also possible for livestock, although it is not without ethical concerns. CRISPR and other gene-editing technologies can be used to identify genes responsible for enhanced traits in animals e.g. better milk production in cattle. These can then be implanted in less productive breeds, which are prevalent in arid regions. The heat tolerance of cattle from more temperate climes can also be improved, thereby allowing them to be bred in hotter regions. Partnering with leading research institutions in bioengineering will be necessary to develop local expertise to global standards. More broadly, agricultural and climate policies must be reconciled if growth of the sector is to be sustained, and research can play a key role in identifying major barriers and determining how resources should be allocated.
Waste
Piles of waste, often aflame, are not uncommon sights in Nigeria and these are responsible for over a tenth of our GHG emissions. In landfill sites, this arises from microbial action that breakdown organic waste to release a mix of gases, predominantly methane and carbon dioxide, into the atmosphere. The incineration of municipal waste, especially plastics and volatile organic compounds (contained in petrol, cleaning agents, paint, building material) releases toxic gases that are potent carcinogens and GHGs. Several measures can be taken to mitigate these emissions sources.
Controlled composting of organic waste can produce fertilisers for crop production, which can displace GHG-emitting synthetic fertilisers used today; methane is also no longer produced as aeration techniques are used. Decomposing organic waste in the absence of air can however produce bio-methane for heat or power generation. This has significantly lower associated GHG emissions than natural gas for the same purpose. Improved sorting and recycling of plastics will be crucial. For these to be possible, however, local and state governments must educate communities on the dangers of uncontrolled combustion or dumping of their waste. Then waste collection/sorting, recycling and processing facilities must be set-up. As there are opportunities to generate revenues from products (fertiliser, biogas, plastic), there is a role for the private sector.
Regardless, the government must provide conducive business and regulatory environments that allow the private sector to thrive. A standardised “code”, for instance, is needed to coordinate waste collection efforts and establish best practices for processing of different waste types. Facilities will need to be engineered to the material they process. Whilst the relevant technologies to achieve this are mature and readily deployable, generating awareness and policy solutions will need to be local efforts. The conversations to kick-start these are virtually non-existent in most states, with the notable exception of Lagos.
Where to Begin
Climate action has suffered from the myopia of political leadership globally, and Nigeria is no exception. Security, health and governance challenges are viewed as more imminent and having more potential for devastation. However, the above has outlined that while climate change effects are gradual, the impacts of climate change will be more widespread and will have detrimental socioeconomic and health consequences.
Underpinning the effective implementation of the solutions discussed is the collection and use of good quality data. Accurate population data and reliable forecasts are critical to understanding how the energy infrastructure should be developed. Developing a sector-by-sector inventory of the GHG emitters is necessary for reliable carbon accounting. A better understanding of site-specific solar insolation and winds speeds will aid the selection of optimal sites for renewable energy projects. Field trials on crop production in local ecosystems will highlight the crops that are most vulnerable to the changing climate and identify areas of research focus.
Together, these developments can be the foundation of technological and policy innovation that can realise low-carbon growth in Nigeria. The sectors that will be developed as a result (renewable energy, waste management, and research) will help to alleviate unemployment and economic stagnation; low-carbon sectors have been shown to grow faster than the wider economy. Financing these efforts will be a challenge but there are many climate funds dedicated to pursuing mitigation and adaptation in developing countries that were established under the Kyoto Protocol and Paris Agreement. Designing policies and projects that satisfy the eligibility criteria for these funds will provide access to much-needed financing⎈
[1] IPCC. (2014). Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, USA: Cambridge University Press.
[2] United Nations, Department of Economic and Social Affairs, Population Division. (2017). World Population Prospects: The 2017 Revision, Key Findings and Advance Tables. New York: Working Paper No. ESA/P/WP/248. United Nations.
[3] Ministry of Environment, Federal Republic of Nigeria. (2015). Nigeria’s Intended Nationally Determined Contribution. Abuja.
[4] Fattouh, B., & Dale, S. (2017). Peak oil demand and long-run oil prices. Oxford: Oxford Institute of Energy Studies.
[5] Otoghile, A., & Ebomoyi, I. (2016). Crisis of Industrialization in Nigeria. Developing Country Studies, 6 (8).
[6] African Energy Live Data. (2018). Nigerian capacity set to increase amid conflicting signs for troubled industry. London: African Energy.
[7] Randall, T. (2016). World Energy Hits a Turning Point: Solar That’s Cheaper Than Wind. London: Bloomberg New Energy Finance.
[8] Ayanlade, A., & Drake, N. (2016). Forest loss in different ecological zones of the Niger Delta, Nigeria: evidence from remote sensing. GeoJournal , 81, 717-735.
[9] Akpan-Ebe, I. N. (2017). Reforestation in Nigeria: History, current practice and future perspectives. Reforesta , 3, 105-115.
[10] Brandt, M., Wigneron, J.-P., Chave, J., Tagesson, T., Penuelas, J., Ciais, P., et al. (2018). Satellite passive microwaves reveal recent climate-induced carbon losses in African drylands. Nature ecology & evolution , 2, 827-835.
[11] Zougmoré, R., Partey, S., Ouédraogo, M., Omitoyin, B., Thomas, T., Ayantunde, A., et al. (2016). Toward climate-smart agriculture in West Africa: a review of climate change impacts, adaptation strategies and policy developments for the livestock, fishery and crop production sectors. Agriculture & Food Security , 5 (26).
[12] Tack, J., Lingenfelser, J., & Jagadish, S. V. (2017). Disaggregating sorghum yield reductions under warming scenarios exposes narrow genetic diversity in US breeding programs. Proceedings of the National Academy of Sciences of the United States of America , 114 (35), 9296-9301.