Forests, peat bogs, wetlands and other ecosystems remove carbon from the atmosphere via photosynthesis and store it in leaves, trunks and roots, and in the soil. But carbon storage in nature is likely temporary because it can be lost again due to either human activities or natural disturbances.
In contrast, the climate effect of carbon dioxide emissions from burning fossil fuels is effectively permanent. If these efforts to increase natural carbon stocks are short-lived, is there any climate benefit?
Our new research suggests that temporary nature-based carbon storage can help achieve our climate goals. However, the most tangible effect — a decrease in peak warming — would only occur if we also eliminate fossil fuel emissions.
But the carbon stored in nature is unlikely to be permanently removed from the atmosphere. Disturbances like wildfire would cause carbon to be lost back to the atmosphere. Conflicting human land-use priorities can also cause previously protected natural areas to be threatened by industrial activities.
If nature-based carbon storage is temporary, then its climate benefit would also be short-lived. We need to think about nature-based climate solutions in relation to other climate mitigation efforts to understand their true benefits.
In our study, we set out to explore what temporary removal would mean for future climate. We used a climate model to simulate the climate response to temporary removal alongside two different future emissions scenarios.
If emissions continue to increase until 2040, followed by gradual decline, global temperatures would rise throughout the century. In this scenario, nature-based carbon removal would only delay the occurrence of a particular warming level. In our highest removal scenario, sequestering a quarter of current annual emissions every year until 2050 only delays the time we reach 1.5 C by a year, and 2 C by eight years.
This might seem small, but it is an important and tangible climate benefit that will only occur if the world also succeeds in eliminating fossil fuel carbon dioxide emissions over the coming decades.
Both of these framings are problematic. If nature-based carbon storage is temporary, then its climate effect is not equivalent to avoiding fossil fuel carbon dioxide emission. This means that treating nature-based carbon storage as an alternative to other emissions reductions will, at best, delay crossing temperature thresholds. At worst, this could lead to more emissions and long-term warming.
On the other hand, if we take action to increase natural carbon storage in addition to ambitious emissions reductions, it could contribute to limiting peak warming. Even temporary nature-based carbon storage could have an important climate benefit.
If done in partnership with Indigenous and other local communities, nature-based solutions could also have positive social co-benefits such as supporting livelihoods and cultural values. Taking a holistic view of nature-based climate solutions would help to realize these multiple benefits.
It is critical that nature-based climate solutions are not presented as an alternative to other climate mitigation options. As a complementary action, however, they could play an important role in meeting both climate and other sustainability goals.
The Conversation Africa is an independent source of news and views from the academic and research community. Its aim is to promote better understanding of current affairs and complex issues, and allow for a better quality of public discourse and conversation.