Measuring a country's capacity to achieve its NDC targets is crucial, because it provides the foundation for improving capacity development, enhancing knowledge and optimising financial flows.
Africa is no longer the carbon sink of the world and is now emitting as much of the product as it stores, a landmark study has revealed.
The groundbreaking research, led by the Future Ecosystems for Africa Programme based at the University of the Witwatersrand (Wits) found that between 2010 and 2019, the continent moved from being a net carbon sink — anything that absorbs more carbon from the atmosphere than it releases — to a net source.
This refers to releasing more carbon into the atmosphere than it absorbs, and means that the rate at which carbon is being released from the continent has increased.
Overall, it is estimated that Africa is a source of 4.5 petagrams, or 4.5 billion tonnes, of carbon dioxide equivalents per year. This is a measure used to compare the emissions from various greenhouse gases based on their global warming potential.
The researchers pointed out that until now, the continent has been producing about 4% of the human-caused greenhouse gases that lead to climate change, and globally, it has also been offering climate services to the globe. This is largely through the intact ecosystems in the tropics, which have been sequestering more greenhouse gases than were released through human-caused activities. Carbon sequestration is the process of capturing and storing atmospheric CO2.
And, while it still serves this purpose, in the last decade the rate at which carbon is being released from the continent increased.
“In terms of global numbers, this means Africa still hovers around 4% of fossil fuel emissions, but actually emits nearly 40% of the global emissions from land use, and is now contributing 3% to 5% of the growing amount of greenhouse gases in the atmosphere,” said Sally Archibald, principal investigator at the Future Ecosystems for Africa programme and a professor in the School of Animal, Plant and Environmental Sciences at Wits.
Surging population
Africa’s population sits at about 1.4 billion, but is set to exceed 2 billion by 2040 and the trend is likely to continue, noted Yolandi Ernst, a researcher at the Wits Global Change Institute and the study’s lead author.
“If we don’t change our ways, we are just going to release more and more carbon because the population is growing and climate change is exacerbating all the problems. We have increasing people, increasing food requirements and then you have climate change making all that worse,” Ernst said.
According to the researchers, key factors in the rise of greenhouse gases on the continent include fossil fuel burning, methane emissions from livestock, soil carbon losses and nitrous oxide emissions as land is converted for agricultural use.
“Anywhere where you uplift the soil — so when you plough your lands, even if it has had croplands and you plough it again — every time, you release the soil carbon. Basically whenever you disturb the soil, then you are going to take out the stored carbon,” said Ernst.
She added that nitrous oxide is one of the three major greenhouse gases (after CO2 and methane) and the emissions were, for example, from fertilisers used for farming.
While natural ecosystems continue to act as carbon sinks across the region and are taking up about 30% of what is being emitted to the atmosphere through human activities, Ernst said that greater swaths of land than ever before are being used for agriculture, and livestock numbers are increasing, with the “net result being that these changes in land use have affected Africa’s role in the global carbon cycle”.
Land use emissions
To make their estimates, the authors followed the budget assessment protocol laid out by the REgional Carbon Cycle Assessment and Processes.
They took a comprehensive look at all major potential carbon sources, including human sources such as agriculture and fossil fuel emissions and natural sources such as termites and wildfires. They also considered natural sinks — grasslands, savannas and forests — that still cover much of the continent.
“Our grasslands and savannas are really important to store carbon,” Ernst said. “I think afforestation plans — these huge tree-planting initiatives — have to be careful not to disturb the natural ecosystems because what we need to protect is the processes that make the system work.”
“If you just start randomly planting trees in a grassland, you are not necessarily going to get the benefit you would want. I’m not saying all of it is bad, but they have to think it through.”
Overall, the researchers estimated that Africa was a source of 4.5 petagrams, or 4.5 billion metric tons, of CO2 equivalents per year, with land use emissions still being higher than fossil fuel emissions. Both are growing rapidly, they said.
Over the past year, the total emissions resulting from human activity, including trade, livestock and fuel burning were estimated at 1.2 petagrams of carbon. Moderate climate conditions and high productivity of the tropical forests helped natural ecosystems to take up about 0.6 petagrams of carbon per year, leaving about 0.6 petagrams of carbon as the net flux, released into the atmosphere.
Their research on Africa’s carbon budget is key to identifying which aspects of the greenhouse gas cycle are most important to be managed in the quest to achieve net zero, and possibly restore the continent’s role as a carbon sink.
Novel ways to manage landscapes
According to Ernst, investing in carbon-neutral energy sources could reduce about 30% of Africa’s human-caused emissions, but novel ways to manage landscapes for livelihoods and carbon storage would be needed to slow the emissions from agriculture and land use.
“As demand for food production increases, we need a focus on climate-smart agricultural practices on the continent, as well as investments that address socio-economic challenges in nature-preserving ways across Africa,” she said.
Protecting, managing and restoring the landscapes helping to take up the excess CO2 is an important part of the solution, “but there are challenges with making carbon storage the main goal of conservation and it can conflict with biodiversity and water provision”.
Ernst added that the Future Ecosystems for Africa Programme is working with scientists, policymakers and carbon projects across the continent.
“It’s a consortium with scientists, policymakers and land owners so we get the information from the people that live on the land and not just from a science point of view.”
Getting their input ensures that the programme is linked with the “right science”, Ernst added.