Mitigation of greenhouse gases in the
land sector is complex and has a unique set of challenges.
The most significant challenges arise from the
geographically diffuse nature of the emissions sources
(compared to, for example, point-based energy sources of
emissions), the vast array of potential management
responses, the ongoing effects of past actions, the
interaction of human and natural processes, and the strong
influences of policy and markets. These factors result in a
large number and diversity of actors involved, temporal
variability in emissions sources and volumes, and higher
uncertainty associated with the processes generating the
emission reductions. Because of this, achieving large-scale
mitigation in the land sector requires collective action
involving multiple stakeholders undertaking different
activities. This paper synthesizes several lessons learned
in efforts to develop systems that integrate incentive
mechanisms at multiple scales. It illustrates many lessons
through examples and the appendix presents individual case
studies from a variety of geographies, Acre (state in
Brazil), Australia, Brazil (Amazon), the Democratic Republic
of Congo (DRC), Guatemala, and Zambia. The hope is that the
experiences of emerging ‘nested’ systems can provide
inspiration to countries developing REDD systems,
particularly those which seek to catalyze across a landscape
local actions that contribute to national mitigation. The
objective of this paper is to share a few lessons from
nested systems. While there are many positive benefits to
nesting, experience suggests that countries struggle with
development of nested systems. Very few have been
operationalized (with exception to a few developed
countries, such as Australia and New Zealand), although
several REDD nested systems are now emerging. Section two
explores four high-level ‘typologies’ that countries may
consider when developing a nested system. Section three
summarizes three key technical challenges that countries
face: alignment of measurement systems, reference levels,
and double counting. Both sections illustrate options using
real-world examples from countries pioneering nested
approaches and explain why certain choices were made. The
paper concludes with thoughts on overall lessons learned,
recognizing that the journey is still young.