Assessing sub-Saharan Africa's GHG emissions from croplands: environmental impacts and sustainable mitigation strategies.

Abstract

Globally, agricultural lands are among the top emitters of greenhouse gases (GHGs), responsible for over 20% of total greenhouse gas (GHG) emissions. Climatic conditions, an acute challenge in sub-Saharan Africa (SSA), where access to mitigation technologies remains limited, have heavily influenced these lands. This study explores GHG contributions from crop production and their devastating and deteriorating impacts on the economy and environment and proposes a sustainable solution. The research design includes the application of various measuring metrics to examine the intensities of climate variabilities using panel data and real-time data from remote sensing (RS). Both sources of data were verified via a blinded comparison of CO₂eqKg emitting capacity from leading cropland emitters in SSA, as a method to eliminate flawed data. Estimate stochastic frontier analysis (SFA) was used to compute the recorded data from 1988 to 2022, in combination with QGIS and Google Earth SFA proved to be the most effective model for assessing the impacts of climate change on production since it was invented and introduced by Aigner, Lovell, and Schmidt in 1977. The deployment of the Sentinel-2 satellite has facilitated the capture of real-time images of land use and land cover (LULC), which revealed an annual average crop yield loss of 58% rendering only 0-40% of the cropland effective for potential crop growth. The investigation further showed that among six closely monitored countries, South Africa had the highest CO₂ equivalent emissions (kg), peaking at 64 kg CO₂eq/kg in 1990 and declining to 58 kg CO₂eq/kg in 2017. Ethiopia, the second-largest emitter, had a 2007 emission rate of 24 kg CO₂eqKg. Nigeria is next, contributing a mean value of 21 kg CO₂eq/kg. It was established that in each of the three (3) nations (South Africa, Ethiopia, and Nigeria) defined as heavy emitters in SSA, the annual contribution quota to global GHG emission is far above what is emitted in industrialized nation. The study revealed that an estimated total cropland of 10,881,657.5 square hectares in North Central Tier (NCT) 2 (Nigeria, Niger) and North Central Tier 3 (Sudan, Ethiopia) is considered the hotspot of the GHG emission index in SSA. The primary causes of emissions were anthropogenic activities and long-standing unsustainable agricultural practices. The implications of the above findings were recorded from 2013 to 2022 as the most diminutive years in the region, with an estimated 21% ecological resource (aquatic species) declined. The economic implications include food insecurity and agricultural job loss, while the environmental effects include climate change, agricultural land loss, and ecological natural resource diminishing in Nigeria, South Africa, Kenya, Mali, Ghana, Burundi, and Zambia due to high GHG annual emission. The study recommends improving crop breeds with significant GHG absorption rates and introducing eco-friendly crop production and land management measures to enhance carbon sequestration from cropland.