This project uses open source remote sensing and GIS data to provide quantitative information on different types of carbon sources across the Gauteng City-Region (GCR). These include green carbon (terrestrial trees, shrubs and grasses), blue carbon (aquatic sources and sediment), teal carbon (wetlands reed beds, sedges and macrophytes), brown carbon (organic, biomass combustion) and black carbon (inorganic, incomplete combustion of fossil fuels and soot).

The quantification of these five components of carbon is crucial for carbon accounting and natural capital accounting (SANBI) exercises within the regional South African context, while also addressing international policy imperatives, which are of particular importance as monetary compensation is given to the countries that can accurately quantify their carbon sources and sinks. International policies on carbon accounting include the Kyoto Protocol and UNFCCC REDD+. REDD+, which stands for “Reducing emissions from deforestation and forest degradation, and foster conservation, sustainable management of forests and enhancement of forest carbon stocks”.

Carbon sinks, such as blue and teal carbon are severely under-represented both in the national and international context due to the difficulty of quantifying, accessing them for field data collection and remote sensing. While quantifying carbon sources, such as brown and black carbon, has the potential to help monitor the environmental compliance of the industrial and energy sectors within the GCR (e.g. ESKOM has been well known to operate outside acceptable emissions levels).

The GCR can serve as a pilot study in which all of these five carbon types can be spatially mapped in an interactive data viewer. This project will rely on collaborations with scientists from the CSIR, Wits, UP and governmental bodies (e.g. South African Weather Services and Gauteng Department of Agriculture and Rural Development) for ground data and possible advice on modelling approaches. The overall modelling approach will rely on the utilisation of regional scale models derived from field plot collections and airborne image datasets.

The project is expected to run for 3 years with the following outputs being envisioned:

1) A multi-authored book on Establishing a Carbon Atlas for the Gauteng City-Region

2) A scientific journal article - “Mapping the green carbon sinks of the Gauteng City-Region”

3) An interactive GIS data viewer on the established Gauteng City-Region Carbon Atlas

Outputs

July 2022 Map of the Month: Distribution of Green Carbon across the GCR

Laven Naidoo and Cher Petersen (March 2023). 'Spatial Distribution of Green Carbon across the Gauteng City Region (GCR): the first step towards a Carbon Atlas for Gauteng'. Presentation. Climate Change Research Conference by City of Tshwane and Tshwane University of Technology, 9 March 2023.

Laven Naidoo (April 2023). 'Current work on estimating green carbon and comparison to existing blue carbon estimates'. Presentation. NMMU and DFFE workshop on prioritisation of blue carbon ecosystems for implementation of restoration measures (online), 18 April 2023.

Laven Naidoo (September 2024). ‘Estimating green and teal carbon stocks across Gauteng using a multi-sensor remote sensing approach’. Presentation. 2024 ForestSAT Conference, Rotorua, New Zealand, 9-13 September 2024

Laven Naidoo (October 2025). 'Measuring the invisible'. ITWeb Brainstorm Magazine Feature Article and Interview, October 2025 Issue.

Laven Naidoo (November 2025). ‘Estimating the major terrestrial carbon stocks across Gauteng using a multi-source remote sensing approach’. Presentation. DFFE GIS Day 2025 – Geospatial Solutions Supporting a Changing World, Webinar, 19 November 2025.

Last updated: 12 December 2025