By Taylor Hinds
At the UN COP26 climate summit, over 100 world leaders pledged to end—and even reverse—deforestation by 2030.
But in 2014, a similar ‘landmark’ agreement was reached–and this didn’t slow deforestation at all. Part of the problem is that decision-makers are locked into trying to solve problems within the framework of the incumbent paradigm. But this paradigm is about to be dramatically transformed, opening up entirely new ways of thinking about forests. Far from focusing purely on ‘band aid’ solutions to slow existing rates of deforestation, what if we could rapidly drive system transformations? These would open up vast new opportunities to not only stop existing deforestation, but to drive unprecedented opportunities for reforestation that could help us solve not just climate change, but the biodiversity crisis?
In RethinkX's 2019, Rethinking Food and Agriculture, we found that the disruption of the food sector–in particular animal agriculture–by existing technologies, namely precision fermentation (PF) and cellular agriculture (CA), is imminent. This disruption will have profound implications for the world as a whole, but particularly for climate change and biodiversity.
The initial climate benefits of the disruption will come from the collapse of the existing animal agriculture industry. Not only do cattle and other livestock emit a massive amount of greenhouse gases (GHG) directly, but their production depends on an extensive, international supply chain powered by fossil fuels and enabled by deforestation. The UNFAO says that livestock are responsible for 14.5% of global emissions, so collapse of this industry will lead to a substantial slash of GHG emissions and a giant leap toward the net zero-emissions goal.
But achieving net-zero emissions is only the first step to solving climate change. We must also take action to remove carbon dioxide from the atmosphere to return concentrations to a safe level, otherwise past emissions will continue to drive global warming for centuries.
Livestock, on top of all the GHG emissions, also takes up a lot of space. Between grazing land and the cropland required to grow their food, the current animal agriculture industry covers about 3.3 billion hectares of land, about a third of the habitable land on earth.
This means that alongside decreasing emissions, the collapse of the inefficient, carbon-intensive food sector sets us up for an unprecedented reclamation of land. In fact, the part of the industry that will be wiped out by the food disruption is responsible for an ecological footprint the size of the United States, China and Australia combined.
The scale and implications of this reclamation–which we call The Great Land Liberation–are profound. Over the next two decades, some 2.7 billion hectares of former pasture and cropland will rapidly be freed up. It is critical that society is prepared to make the right choices to take advantage of this extraordinary opportunity and help correct course on climate change.
This blog is a summary of the RethinkX report Rethinking Climate Change (2021), by James Arbib, Adam Dorr and Tony Seba.
There is currently no clear scientific consensus on how much carbon withdrawal will be necessary to avoid the worst impacts of climate change. Therefore, the most sensible precautionary approach is to fully restore the atmosphere to its pre-industrial composition by aiming to remove hundreds of gigatons of carbon.
Reforestation is a very attractive solution because it is simple, natural and inexpensive. There are no unproven technologies, no questions about safety and no waste production. Restoring forests brings back animal habitat, stops extinctions and protects natural resources. Above all, trees are an effective method of carbon sequestration: a single mature tree absorbs 48 pounds of CO2 per year.
In Rethinking Climate Change, all three of our greenhouse gas emission scenarios take reforestation into account. The scenarios are based on the various choices societies can make now to either accelerate or slow down the three sector disruptions and how those disruptions will affect the climate in the future. If society makes the right choices and this is done correctly, going beyond net-zero emissions is achievable by 2035. This will eliminate the key drivers of deforestation and also open up massive opportunities for reforestation.
The most important choice, or rather set of choices, is to accelerate the food disruption. PF and CA exist and are ready to deploy and scale. Accelerating the disruption at this point means breaking down barriers to PF and CA adoption by letting market forces take the lead. That requires breaking up agricultural monopolies, removing prohibitive legislation, stopping the support of incumbents with subsidies and so on. The sooner the disruption proceeds, the sooner the animal agriculture industry collapses and the sooner land becomes liberated. As this happens, increasing opportunities for reforestation emerge. Forests take time to grow, and peak sequestration happens when the forests are mature. Time is of the essence here–we as a global society cannot afford delay.
As the disruption proceeds and livestock populations begin to drop, more and more land will rapidly become available. Without a plan or deliberate decision-making, this land is at risk of being misused. Given the size of the opportunity, there will certainly be competing interests for the use of this land.
So it is imperative that land freed up from livestock is used in a way that benefits the planet and helps address the ecological crisis. This land must be restored, not degraded. This opportunity is too big to waste.
The rate of carbon sequestration on a given piece of land can be greater if societies choose to implement active reforestation–i.e., the deliberate planting of trees and vegetation.
The other option is to leave the land to its own devices. This is called passive reforestation, which involves allowing plants to grow wherever and whenever they like with little to no interference.
Both methods are effective ways of reforesting land and each has its own advantages and disadvantages. Active reforestation requires capital investment, labour, machinery and energy–but in return, the forest regenerates faster and can be designed to sequester the maximum amount of carbon.
Passive reforestation is completely free, assuming the land does not need to be protected from degradation, but the forests will regenerate much slower than if they had been actively planted. The area may start off with much smaller vegetation like grasses or shrubs before the trees grow to create what we think of as a forest.
Source: Rethinking Climate Change, RethinkX (2021)
With our goal of sequestering the most carbon as quickly as possible, active reforestation seems like the better solution. But we are talking about an enormous amount of land. It would be nearly impossible to get a project the size of 2.7 billion hectares done within a reasonable amount of time. And despite the longer timeline, passive reforestation still results in substantial carbon sequestration in above-and below-ground biomass.
If the whole 2.7 billion hectares of land freed up from animal agriculture by the food disruption were left to passive reforestation, it would offset 9% of global emissions annually by 2030, and 20% by 2035 and thereafter.
But if we were to actively reforest 20% of this freed land while the remaining 80% undergoes passive reforestation, together this would offset 8% of emissions by 2030 and roughly 21%, or 10 gigatons CO2e carbon, per year, from 2035 onward. This would be at a total cost of $517 billion over a 25-year time frame or an average of $21 billion per year.
This suggests that it would be apt to prioritize active reforestation where possible, and allow for passive reforestation everywhere else.
Some ecosystems need intense land restoration before forests can regenerate, particularly if the land has been significantly degraded. Mangrove forests are one such example as coastlines often need to be restored before the mangroves will grow back. They also happen to be a superb carbon sink, so targeting niche ecosystems like this with active reforestation or restoration will be important.
In Rethinking Climate Change, we modeled reforestation by biome–i.e., the community of vegetation and wildlife adapted to a specific climate. This is key because the amount of carbon sequestered by a plant depends on the type of vegetation, which in turn depends on the local climate.
This is crucial for forecasting and analysis because a reforested patch of land in one country may have a dramatically different carbon sequestration than a patch of the same size in another. As one might expect, fully grown forests hold more carbon per hectare in their biomass than grasslands or deserts. But forests take a very long time to grow whereas grasslands reach their maximum sequestration level much sooner-not to mention the differences in the amount of soil carbon sequestration. Essentially, different biomes have different rates of sequestration which change over time so that each biome reaches its own storage capacity.
Source: Rethinking Climate Change, RethinkX (2021)
Paying attention to vegetation is perhaps even more crucial for active reforestation because planting the incorrect species, whether non-native, invasive or ill adapted, could have catastrophic consequences for the environment.
Reforested land is not guaranteed to become a successful carbon sink, so active reforestation needs to be done deliberately and with care.
The goal is to build an ecosystem and not a monoculture or a plantation. It is important to plant a diversity of species, even if some of those species are not the most effective sequesters of carbon. Monocultures are highly vulnerable to disease and logging and do not support biodiversity of wildlife in the same way a more complete ecosystem would.
Planted vegetation also needs to be cared for and monitored to ensure that it takes successfully to the landscape. If it does not, any carbon sequestration claimed by the project leaders is not actually being achieved.
High-quality reforestation must also consider the human aspect. If there are local or indigenous inhabitants in or around the land that is to be restored, it is crucial that those people approve of or are involved in the project. Without this, it leaves the forest susceptible to logging and degradation and leaves people open to exploitation and infringement of their rights. Forests and other healthy ecosystems bring ecosystem services to local populations. These restoration projects should be a net-positive contribution to the community.
While the food disruption is playing out over the course of the 2020s, two concurrent disruptions of the transportation and energy sectors will be simultaneously occurring. The set of technologies disrupting these sectors–including solar, wind and batteries (SWB) for energy and autonomous electric vehicles (A-EV) for transportation–will make other forms of carbon withdrawal technologically and economically feasible for the first time. Ocean alkalinity enhancement (OAE), direct air carbon capture and storage (DACCS), and other carbon withdrawal methods are all currently costly because of their energy, vehicle (machinery) and labor requirements.
Yet these technologies will become much more affordable thanks to SWB super power, electric vehicles and machinery that run on clean electricity, as well as automated vehicles and machinery that do not require human operators.
Active reforestation on 20% of freed land. Source: Rethinking Climate Change, RethinkX (2021)
We estimate that as a result of these disruptions, the cost of carbon withdrawal through both active reforestation and technology-based approaches can fall to under $10 per ton by 2040. This will make it affordable to go below zero emissions, restore carbon dioxide concentrations in the atmosphere to safe levels and achieve a full solution to climate change.
The pledges at COP26 are a welcome step forward–but simply fulfilling them within the existing system won’t work. The fastest and most effective way to stop deforestation and accelerate reforestation is therefore through the acceleration of the disruptions of the food sector, as well as the energy and transportation sectors.
