Concerns about the impact of climate change are driving the need for stabilising the global temperature rise to below 2oC. In parallel to countries making commitments under the Paris Agreement, sector decarbonisation trajectories are being developed. Globally, collective action is required, and cities and companies are increasingly requested to voluntary set greenhouse gas (GHG) targets. Tracking progress is key to meeting the objectives of the Paris Agreement. In order to track progress against a GHG target or commitment, a credible GHG inventory, as well as the associated emissions reduction from GHG mitigation actions, are required. An analytical technique was developed the present GHG inventory, corrected if needed, together with the GHG mitigation actions to construct a counterfactual baseline. This counterfactual baseline is compared to the GHG target in one infographic. South Africa committed to a peak, plateau, and decline trajectory. However, the latest publicly available inventory is for 2010, but can be extrapolated based on trade statistics. The inventory is based on the default Tier 1 coal calorific values of the Intergovernmental Panel on Climate Change (IPCC) and could be over reported by 20%. A methodological approach is proposed, where the emissions from coal calorific value, together with trade statistics, are quantified and presented together with the GHG emission reduction estimates of implemented mitigation policies and measures. Companies in the mining sector of South Africa voluntary signed a 15% GHG reduction over a ten-year period from 2005, linked to the South African Energy Efficiency Accord. GHG emissions increase as mining companies transport ore over increased distances in opencast operations, or extract ore from deeper levels in underground operations. The GHG inventories of a gold and an iron ore mining company, together with the implemented projects, are analysed to evaluate progress. The decarbonisation trajectories of cities are linked to the implementation of national commitments and voluntary target setting commitments under the Global Covenant of Mayors. Within a developing country context, with rapid urbanisation and limited data, tracking the greenhouse gas inventory against the targets is challenging. This study looks at four cities in South Africa that made greenhouse gas reduction commitments and supplied inventory data into publicly available databases. The greenhouse gas data for each city is extrapolated based on official data from national census and socio-economic studies. The formal commitment to meeting the sustainable development goals was announced 2016, to providing basic drinking water, sanitation, electricity, as well as transport for citizens currently unemployed. This study provides insights into the trade-off between additional GHG emissions in meeting the sustainable development goals in fast-growing cities of a developing country, and the decarbonisation commitment of these cities. Tracking progress against absolute greenhouse gas reduction targets should take the uncertainties of the underlying data for GHG inventories, and mitigation outcomes, into account. Quantification of the emission reductions of implemented mitigation initiatives is critical in managing emissions against a GHG mitigation trajectory. The importance of this study is to enhance transparency in a data poor environment, while keeping the focus on mitigation action.