Sulphur Dioxide SO₂ Ozone O₃ Aerosols Urban Climate Change Anthropogenic Activities Thermal Environment Air Pollution Spatial Analysis

The rapid urbanization of the 21st century significantly alters local climates, manifesting in phenomena like the Urban Heat Island (UHI) effect and elevated concentrations of greenhouse gases (GHGs). The COVID-19 lockdown offered a rare natural experiment to evaluate the extent to which human activities influence urban thermal environments and atmospheric conditions. This study employed remote sensing and Geographic Information System (GIS) techniques to analyse the effects of the COVID-19 lockdown on Urban Heat Islands (UHIs), Land Surface Temperatures (LST), and Greenhouse Gases (GHGs) in Abuja, Nigeria. Landsat 8 satellite imagery was used to derive UHI and LST data, while Sentinel-5P provided atmospheric measurements for key GHGs including sulphur dioxide (SO2), aerosols, and ozone (O3). The analysis covered three temporal phases which are the pre-lockdown (2017–2018), lockdown (2019–2020), and post-lockdown (2021–2024) and data were processed using Google Earth Engine and ArcGIS environments to classify spatial variations and identify thermal patterns across the study area. The results revealed a significant decline in both UHI and LST intensity during the lockdown period, with mean UHI values dropping from 6.00°C in 2017– 2018 to 4.93°C in 2019–2020, before rising again to 6.72°C post-lockdown. LST followed a similar trend, decreasing from 6.96°C to 5.14°C during lockdown and increasing thereafter. A corresponding reduction was also observed in atmospheric pollutants, with sulphur dioxide, aerosols, and ozone concentrations all declining during the lockdown. Pearson correlation analysis showed a strong positive relationship between UHI and LST (r = 0.786–0.877), confirming their interdependence and direct link to anthropogenic activity. These findings underscore the dominant role of human activities in shaping urban climatic and atmospheric conditions. The temporary cooling and emission reduction during the lockdown illustrate the potential environmental benefits of reduced fossil fuel consumption and improved urban planning. The study highlights the critical importance of integrating green infrastructure, energy-efficient systems, and climate-responsive policies into Abuja’s urban development framework. It further demonstrates the value of remote sensing and GIS as essential tools for continuous environmental monitoring and policy formulation toward achieving Sustainable Development Goals 11 (Sustainable Cities and Communities) and 13 (Climate Action)