Introduction
Agriculture, together with agriculture-driven conversion
of land, contributes between 7.3 and 12.7 Gigatonnes of
carbon dioxide equivalent (CO2e) globally per year —
approximately 15–25% of total global anthropogenic
greenhouse gas emissions [1]. Agroforestry, a land-use
system that incorporates tree-growing on agricultural land,
offers an opportunity to remove CO2 from the atmosphere
by storing it in tree biomass and soil organic matter [2].
This, coupled with agroforestry’s potential to deliver a
range of benefits to some of the world’s poorest people,
including improved productivity, greater food security,
reduced poverty and increased resilience to climate
change, has garnered it increasing international attention
(e.g. [3–6]). Worldwide, agroforestry comprises approximately
1 billion hectares, with roughly 560 million people
in developing countriesrelying directly on the services and
products agroforestry provides [7,8]. One option for incentivizing
the adoption of agroforestry technologies in developing
countries is through biocarbon projects, in which
local land users receive payments through international
carbon markets in exchange for carbon sequestered on
their land. Despite rising interest in agroforestry, however,
the majority of biocarbon projects to date have focused on
Reducing Emissions from Deforestation and forest Degradation
(REDD) [9], where projects can generate carbon
creditsrelatively rapidly.Within the agriculturalsector, our
knowledge base is limited to a handful of projects (PetersStanley
et al. [9] report only six agricultural projects worldwide
that transacted creditsin 2011), the majority of which
have been implemented recently and whose long-term
viability is uncertain