By Jeremy Allouche and Detlef Müller-Mahn*
BONN, Germany | 22 January 2025 (IDN) — Carbon offsetting—the practise where businesses or individuals offset their carbon emissions by investing in environmental projects – is expanding from reforestation projects to tree planting in areas with no history of tree cover, such as semi-arid to arid lands, despite the serious doubts over how much carbon these new forests will capture.
The huge environmental project stretching across the Sahel region of Africa, known as the Great Green Wall (GGW), provides the biggest example yet of why the hype around carbon offsetting projects should not derail global leaders from pursuing more proven and strategic climate change mitigation measures.
Forestry is a key sector for climate change mitigation, given the capacity of trees to capture and store carbon. However, privileging forestry for carbon capture, means that less attention is given to fossil fuel. This is especially important given that there is a key difference between land carbon and fossil carbon. There are also numerous other limits, one being the difficulty in quantifying the amount of carbon sequestration from forestry. More accurate methods of estimating avoided deforestation are urgently needed.
The limits of carbon offsetting
The limits of carbon offsetting are now increasingly well known. In fact, a recent study evaluating more than 2,000 carbon offset projects concluded that only 12 percent of the total volume of existing credits constitute real emissions reductions. Despite these shortcomings, carbon offsetting is frequently seen as playing a significant role in combatting climate change.
The Great Green Wall Accelerator (GGWA), launched by French President Emmanuel Macron and other world leaders in 2021, is the most spectacular example of this positive view of carbon offsetting though tree planting – via reforestation and afforestation projects.
It aims to restore 100 million hectares of degraded land, create 10 million green jobs in rural areas and sequester 250 million tons of carbon by 2030.
However, at the African Climate Summit in 2023, despite the significant pledges to purchase carbon offsets from African countries, especially by Gulf states, the Great Green Wall was largely absent. There are no signs of carbon offsets driving action in Senegal and Ethiopia in the GGW areas, according to our own research on the ground.
The question arises as to why such a prestigious project that received so much international support so far has not been able to use its reforestation activities to access international carbon finance.
Three factors
Our research on the Great Green Wall highlights three factors that help to explain this failure.
- The potential for carbon sequestration in the GGW zone is limited, because it is situated in an arid and semi-arid area.
- The performance of reforestation activities in the GGW partner countries so far has lagged behind the original plans. Our research project, in line with other studies reveals that reforestation activities face serious problems, most notably the fact that the figures reported to the central agencies of the GGW at national and international levels are based on the planted areas, but they do not take into account the low survival rates of seedlings.
- A sufficiently capable institutional framework to promote the carbon market and provide guarantee is not in place. In July 2015, the Summit of Heads of State and Government of the Pan-African Agency of the Great Green Wall (PAGGW) decided to create the “GGW Carbon Bank”, which was an initiative from the Sudanese government dating from 2012 (Establishment Of Great Green Wall Carbon Bank).
The Bank was supposed to function on different financial mechanisms and sources: payment for ecosystem services; debt-for-nature swaps; green bonds and other bonds; and return on services offered. Ten years later, the Carbon Bank is yet to materialise, although it remains an important part of the GGW 2030 strategy.
In conclusion, semi-arid to arid lands areas should be treated differently in carbon debates. Project plans, including for the Great Green Wall, should acknowledge that afforestation and tree planting in these dry landscapes is largely ineffective in addressing climate change, as they only have limited potential to capture and store additional carbon.
*Jeremy Allouche is Professorial Fellow, Institute of Development Studies, UK; Detlef Müller-Mahn is Professor, University of Bonn, Germany. [IDN-InDepthNews]
Image source: The Global Environment Facility
