for human societies [1]. Based on the nine PBs, a safe operating space for humanity
was determined [1, 2]. Here, the safe operating space refers to a relatively stable
state called the Holocene epoch, in which human societies can continue to develop
and thrive [2]. Today, both the scientific and political communities have agreed
upon the notion that there are global limits for the Earth system and they should be
respected. Consequently, studies adopting the PBs have started proliferating, and
they can be classified into works that (i) define or refine the control variables and
the associated thresholds [e.g. 1, 2], (ii) downscale the global PBs to sub-global
levels [e.g. 3, 4], (iii) set impact reduction targets [e.g. 3, 4], and (iv) devise policies
and strategies [e.g. 3, 5].
While the PBs concept sets global limits for environmental impacts to benchmark a system’s performance globally, environmental sustainability assessment
methods (ESAMs) such as Life Cycle Assessment (LCA) and environmental
footprints evaluate the environmental performance of a so-called product system
(which is usually defined in terms of supplying a specified quantity of an economic
product or service). Generally, the outcomes of an LCA or environmental footprint
study guide decision makers to improve the eco-efficiency of the chosen product
system through identifying the environmental hotspots along its life cycle [6]. As a
result, use of LCA and other related life cycle thinking approaches to support
decision-making has become common within the business and academic communities [6]. However, although the outcomes of these studies guide eco-efficiency
improvements, the overall progress achieved in mitigating environmental problems
still remains slow and insignificant [7–9]. One contributing factor is that conventional ESAMs like LCA do not benchmark the environmental sustainability performance of a system against a set of environmental boundaries (or standards).
Instead, they rank a particular system in relative terms, by comparing it with a
reference system that is relevant to the nature or the function of the system under
investigation, and thus, the variations in the consumption and production patterns of
the examined products and services are overlooked [7–9]. For example, Product A
may be superior (or more sustainable) than Product B in terms of eco-efficiency, but
neither could be sustainable on an absolute scale due to the predicted growth in
global production and consumption volumes of the product [7, p. 325].
Therefore, recently, the scientific community began to focus on the so-called
concept of absolute sustainability. Absolute sustainability is focused on how human
societies can operate within the carrying capacity of the Earth system [8, 9]. Here,
the term “carrying capacity” refers to “the maximum sustained environmental
interference a particular system can withstand without experiencing negative
changes in structure or functioning that are difficult or impossible to revert” [6,
p. 1007]. As a result of growing interest in absolute sustainability, scientists have
started developing absolute sustainability assessment methods (ASAMs) by supplementing the existing ESAMs with the Earth’s carrying capacity [6, 8, 9], for
instance, supplementing the ecological footprint with the Earth’s biocapacity
(available bio-productive area) [e.g. 10], LCA with PBs [e.g. 6, 8] and environmental footprints with PBs [e.g. 5].
414
C. Chandrakumar and S. J. McLaren
was determined [1, 2]. Here, the safe operating space refers to a relatively stable
state called the Holocene epoch, in which human societies can continue to develop
and thrive [2]. Today, both the scientific and political communities have agreed
upon the notion that there are global limits for the Earth system and they should be
respected. Consequently, studies adopting the PBs have started proliferating, and
they can be classified into works that (i) define or refine the control variables and
the associated thresholds [e.g. 1, 2], (ii) downscale the global PBs to sub-global
levels [e.g. 3, 4], (iii) set impact reduction targets [e.g. 3, 4], and (iv) devise policies
and strategies [e.g. 3, 5].
While the PBs concept sets global limits for environmental impacts to benchmark a system’s performance globally, environmental sustainability assessment
methods (ESAMs) such as Life Cycle Assessment (LCA) and environmental
footprints evaluate the environmental performance of a so-called product system
(which is usually defined in terms of supplying a specified quantity of an economic
product or service). Generally, the outcomes of an LCA or environmental footprint
study guide decision makers to improve the eco-efficiency of the chosen product
system through identifying the environmental hotspots along its life cycle [6]. As a
result, use of LCA and other related life cycle thinking approaches to support
decision-making has become common within the business and academic communities [6]. However, although the outcomes of these studies guide eco-efficiency
improvements, the overall progress achieved in mitigating environmental problems
still remains slow and insignificant [7–9]. One contributing factor is that conventional ESAMs like LCA do not benchmark the environmental sustainability performance of a system against a set of environmental boundaries (or standards).
Instead, they rank a particular system in relative terms, by comparing it with a
reference system that is relevant to the nature or the function of the system under
investigation, and thus, the variations in the consumption and production patterns of
the examined products and services are overlooked [7–9]. For example, Product A
may be superior (or more sustainable) than Product B in terms of eco-efficiency, but
neither could be sustainable on an absolute scale due to the predicted growth in
global production and consumption volumes of the product [7, p. 325].
Therefore, recently, the scientific community began to focus on the so-called
concept of absolute sustainability. Absolute sustainability is focused on how human
societies can operate within the carrying capacity of the Earth system [8, 9]. Here,
the term “carrying capacity” refers to “the maximum sustained environmental
interference a particular system can withstand without experiencing negative
changes in structure or functioning that are difficult or impossible to revert” [6,
p. 1007]. As a result of growing interest in absolute sustainability, scientists have
started developing absolute sustainability assessment methods (ASAMs) by supplementing the existing ESAMs with the Earth’s carrying capacity [6, 8, 9], for
instance, supplementing the ecological footprint with the Earth’s biocapacity
(available bio-productive area) [e.g. 10], LCA with PBs [e.g. 6, 8] and environmental footprints with PBs [e.g. 5].
414
C. Chandrakumar and S. J. McLaren