Last month’s climate Conference of the Parties meeting in Egypt was a sobering reminder of the world’s ongoing inability to reduce greenhouse gas emissions to meet Paris Agreement targets. Given this failure, urgent discussions have begun regarding the need for negative emissions technologies (NETs) to remove existing CO2 from the atmosphere, ranging from direct air capture to afforestation and bioenergy with carbon capture and storage (BECCS).
Currently, integrated assessment models that are used to understand and develop the pathways needed to reach temperature targets show that 1.5° degrees can only be achieved through rapid deployment of NETs alongside aggressive mitigation measures. Yet there are many potential risks of using NETs, particularly for rural and poor people in the Global South, where climate change impacts are already burdening communities, even though options like tree planting or BECCS are often seen as more benign than other carbon dioxide removal strategies. The risks of NETs are ignored in many models, which often fail to include adequate attention to social factors in their analysis.
There are a range of possible NETs, but afforestation and BECCS tend to feature most prominently in the models. While models clearly show that the use of NETs will come with trade-offs such as rising food prices (as land is shifted from growing food to trees and energy crops instead), many potential social impacts can only be modelled in the most general of terms. Some risks of NETs, including gender inequity, farmer displacement, or labour migration, cannot currently be forecasted at all. I have argued in a recent paper that there are four key topics that will be essential to understanding the trade-offs involved in NETs: land, labour, capital and politics.
Who decides what land is ‘marginal’?
It is crucial to understand where and how NETs will create land use change, and the implications of land tenure, dispossession, or consolidation. Models usually assume that NETs will be produced on degraded and marginal lands not suitable for agriculture, thereby avoiding competition with food production, but there is no clear definition of what ‘marginal land’ means. In the real world, what gets called ‘marginal’ is highly subjective, and the term is sometimes used as a political calculation to expropriate existing land users. The worrisome land grabs that have resulted from expansion of biofuels in the past decade have been linked to rising food insecurity and poverty, particularly from large-scale land acquisitions.
Models do not say much about who will fund NETs and where this capital will come from: they simply use a set price on carbon. In reality, international accounting rules on carbon credits will shape how markets for NETs will develop, and experience from previous voluntary carbon markets shows that measurement, verification, and valuation are key roadblocks that few funding schemes have been able to overcome.
Numerous questionable carbon investments in the past point to the need for additional transparency and clarity. What types of investors will be involved, how they will be regulated, and – importantly – the distributional impacts of north-south investment flows for NETs are, as of now, completely unknown.
NETs require labour, such as for tree planting or biofuel harvesting, but we do not know how these activities will impact labour markets or migration patterns. Most models do not look at labour costs and instead assume that with high enough carbon prices, labour will simply be made available. Yet low-wage and unsteady labour has been common in many existing forest carbon projects, while, for biofuels, the employment generated has varied depending on the feedstock. The expansion of biofuels in Africa, for example, has resulted in a clear net loss of farming jobs, with an estimated four people displaced for every hectare of land acquired.
NETs may also drive local and regional labour migration; experience from previous tree planting projects shows migrants may be preferred because of their willingness to work hard for low pay. Gender inequities are a possible outcome: for example, women are often involved as labourers but not as owners or beneficiaries of tree-planting programs.
Fundamentally, NETs will need a social license to operate, and levels of community support will depend on existing local values, public awareness of the risks, and the way benefits are shared. Understandably, many rural communities have declined to participate in afforestation or other carbon projects that do not account for local conceptions of justice and equity, or where corporate interests outweigh those of local land users. Models simply cannot recognise or incorporate these political issues, leaving us with little understanding of where NETs will actually operate and where they will be greeted with fierce opposition.
To fix these problems, we need to address both models and real-world projects as NETs develop. The opaque nature of climate modelling has led to misunderstandings of the role of NETs in future projections. We need to recognise these models’ limitations: they cannot address many known challenges like ethics, governance, and other social issues, and so must be used with caution.
Some of these problems within models could potentially be fixed, including attention to issues like land tenure, conflicts or land grabs which could be included in spatially explicit models, while adding indicators related to employment and sources of capital could also improve forecasts.
In the real world, though, NETs will need to have mechanisms for transparency, accountability, responsiveness, and legitimacy to be accepted and to reduce their impacts on local populations. Rural communities need to be part of any discussions and alliances in sites of NET deployment. Specific rights for smallholder producers, or mandated benefits for local communities like clean electricity, could also contribute to acceptability. There may also need to be an explicit acknowledgement of uneven risks and perhaps prohibitions on NETs in some areas. Ultimately, though, the more that countries act now on climate mitigation, the less they must rely on uncertain NETs later on.
Pamela McElwee is Professor of Human Ecology at the School of Environmental and Biological Sciences at Rutgers University. She has served as a lead author for the Intergovernmental Panel on Climate Change (IPCC) and currently co-chairs the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) “nexus” assessment on the interlinkages between biodiversity, water, food, climate and health.