Climate Change and Human Activities: Their Roles in Shaping Land Productivity in Northern Nigeria

The Northern Nigeria Region (NNR) has historically suffered from land productivity changes due to anthropogenic and climatic factors. The development of methodologies that can evaluate these changes at the pixel level and spatialize the effects of driving factors is a key requisite to provide targeted solutions for land degradation, in a country with population growth and desert advancement. In this study, we applied MODIS series data to assess land productivity changes in the NNR (2001–2021) using NDVI trend analysis. We also used correlation and RESTREND analyses to discriminate between climate and human factors and map their effects. The results indicated that approximately 30.7% of the NNR showed land degradation, whereas 27.1% showed an increase in land productivity. There was a clear spatial pattern, with increasing productivity closer to the northern Nigeria boundary with Niger, and decreasing productivity concentrated in the central and southern parts of the NNR. Anthropogenic factors had a greater impact on land degradation and improvement, compared with rainfall. The climate forcing contributed most to land productivity in the northeastern part of the NNR. Land degradation is mainly associated with overgrazing and unsustainable agricultural practices, which lead to decreasing productivity of grasslands and crops. On the other hand, human influence on improvements involves land abandonment and recovery programs. These results can be used to planning initiatives to better integrate food production with environmental protection in the NNR, contributing to policies to Nigeria achieving land degradation neutrality as soon as possible.