Evaluation of New Zealand's absolute environmental sustainability performance : development and application of a method to assess the climate change performance of New Zealand's economic sectors : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Science in Environmental Life Cycle Management, School of Agriculture and Environment, Massey University, Manawatu, New Zealand
Existing environmental sustainability assessment methods such as Life Cycle Assessment
and environmental footprints quantify the environmental impacts of a system and compare
it to a system that is similar to the nature or the function of the examined system. Hence,
they are referred to as relative environmental sustainability assessment (RESA) methods.
Although they provide useful information to improve the eco-efficiency of the system at a
particular economic level, they generally fail to inform the environmental sustainability
performance of a system against the so-called absolute environmental boundaries. Therefore,
the significance of the contribution of an examined system to the overall environmental
impacts of human activities is mostly overlooked. To address the limitations associated with
RESA methods, researchers have suggested the development of absolute environmental
sustainability assessment (AESA) methods, which guide how human societies can operate and
develop within absolute environmental boundaries.
In this context, this research investigated the development of an innovative AESA
framework called ‘Absolute Sustainability-based Life Cycle Assessment’ (ASLCA) based on
the environmental indicators and absolute environmental boundaries proposed in three
popular frameworks: Planetary Boundaries, Sustainable Development Goals and Life Cycle
Assessment. The proposed framework was applied to assess the production-based climate
change performance of New Zealand agrifood sector, particularly in terms of the two-degree
Celsius (2°C) climate target. The results showed that the production-based greenhouse gas
(GHG) emissions of New Zealand agri-food sector and its products exceeded the assigned
shares of the 2°C global carbon budget. Similar results were observed when the consumptionbased
climate change performance of a typical New Zealand detached house was evaluated
against the 2°C climate target.
The framework was then applied to address the consumption-based climate change
performance of an economic system using environmentally-extended multi-regional inputoutput
analysis. This framework was used to evaluate the consumption-based climate
change performance of New Zealand’s total economy (covering 16 sectors) in 2011 against
the 2°C climate target, and the outcomes were compared with the production-based climate
change performance in the given year. The consumption-based analysis showed that New Zealand exceeded the assigned share of the 2°C global carbon budget; the consumptionbased
GHG emissions were 26% more than the assigned carbon budget share. However,
the sector-level analysis indicated that three of the 16 sectors (financial and trade services,
other services and miscellaneous) were within their assigned carbon budget shares. When
the consumption-based GHG emissions were compared with the production-based GHG
emissions, New Zealand was a net exporter of GHG emissions in 2011, and the dominating
sectors were quite different. The results clearly imply that a significant reduction in GHG
emissions associated with New Zealand’s consumption and production activities are
necessary to stay within the assigned shares of the 2°C global carbon budget.
Given that AESA methods (including ASLCA) are built upon multiple value and
modelling choices, the outcomes of these studies may vary depending upon these choices.
Therefore, the influence of different value and modelling choices on the outcomes of the
ASLCA was investigated, particularly regarding the choice of GHG accounting method,
the choice of climate threshold, the choice of approach to calculate the global carbon
budget, and the choice of sharing principle to assign a share of the global carbon budget.
The analysis showed that, for each GHG accounting method the largest uncertainty was
associated with the choice of climate threshold, followed by the choice of sharing principle,
and then the choice of calculation method for the global carbon budget.
Overall, the proposed ASLCA framework aims to address the question, “Are the
environmental impacts of a system within the assigned share of the Earth’s carrying
capacity, and if not, what is the required reduction?” The outcomes of this research are
useful to support policymakers in understanding the climate impacts of different economic
sectors, goods and services, relative to global climate targets. The approach provides a basis
for developing a range of environmental impact reduction targets that can potentially
catalyse innovation and investment in the environmentally-transformative activities and
technologies that are needed to enable human societies to operate and develop within the
Earth’s “safe operating space”.