Manfred Lenzen

The University of Sydney · Centre for Integrated Sustainability Analysis (ISA)

In 2019 the Australian Capital Territory (ACT) government stated an ambition to prioritise reduction of Scope 3 greenhouse gas emissions, the size of which had not been fully quantified previously. This study calculated the total carbon footprint of the ACT in 2018, including Scope 1, 2 and 3 emissions and modelled scenarios to reduce all emissions...

Non-technical summary Globalisation has narrowed the gap between producers and consumers. Nations are increasingly relying on commodities produced outside of their borders for satisfying their consumption. This is particularly the case for the European Union (EU). This study assesses spillover effects, i.e. impacts taking place outside of the EU bo...

Identifying local energy sources and devising a circular economy could improve self-sufficiency in many Pacific Islands. On the islands with significant agriculture, the residue from the cultivation of plants has promising energy potential. The waste stream is another potential source of energy that otherwise should undergo proper treatment. Additi...

Background: Dietary guidelines that form the basis for food and nutrition policies in most countries are focused mainly on the social dimensions of health. Efforts are needed to incorporate environmental and economic sustainability. As the dietary guidelines are formulated based on nutrition principles, understanding the sustainability of dietary...

Pesticides are well-recognised pollutants that threaten biodiversity and ecosystem functioning. Here we quantify the environmental footprints of pesticide use for 82 countries and territories and eight broad regions using top-down multi-region input-output analysis. Pesticide footprints are expressed as hazard loads that quantify the body weight (b...

Fixed capital stock functions as an embodied energy storage system that connects economic activities which do not happen simultaneously. This paper constructs a dynamic energy input-output model to analyze embodied energy flows and stocks along both temporal and spatial dimensions from 2000 to 2014. The results show that 2043 exajoule of embodied e...

Accounting for carbon should be undertaken at multiple scales to create awareness of the negative environmental impacts of consumption. We undertake a comprehensive consumption-based supply-chain assessment of a community's emissions for a selected council area in the Greater Sydney region of Australia using multi-regional input-output analysis, by...

Desertification threatens food security and human nutrition through its impacts on agricultural productivity. The damage caused by desertification includes both direct, on-site impacts and wide-ranging indirect, off-site effects. In this study, we applied a multi-region input-output framework to estimate the direct and indirect consequences of dese...

In the context of renewable energy (RE) generation, biomass resources are different to other renewable resources because they can be stored and transported. These characteristics make bioenergy a dispatchable renewable energy source. While this property is recognised as being very important in supporting the global energy transition, the potential...

Disasters resulting from climate change and extreme weather events adversely impact crop and livestock production. While the direct impacts of these events on productivity are generally well known, the indirect supply-chain repercussions (spillovers) are still unclear. Here, applying an integrated modelling framework that considers economic and phy...

The flows of people and material attributed to international tourism exert a major impact on the global environment. Tourism carbon emissions is the main indicator in this context. However, previous studies focused on estimating the emissions of destinations, ignoring the embodied emissions in tourists’ origins and other areas. This study provides...

Footprint indicators are used to evaluate chemical substance management. However, determining the impact of chemical restrictions on manufacturing processes and supply chains without a footprint analysis of the entire lifecycle is difficult. Here, we propose a new framework for estimating chemical toxicity footprints utilizing the risk-screening en...

Responding to the global crises - Covid19 and climate change - governments around the world are formulating green recovery plans to stimulate economic growth, boost clean energy technologies and cut emissions. Potential transition pathways for low carbon energy systems, however, remain as open questions. Generally, the simulation of biomass in the...

Degrowth can aid climate mitigation in the food system by integrating reduced animal protein demand, emissions pricing and wealth redistribution into a global food systems transformation.

The frequency of disasters has been increasing over the past decades, fuelled by natural phenomena and climate-related events. Policymakers require robust methodologies to assess supply-chain impacts of disasters. Input–output-based disaster approaches are able to assess such impacts; however, they rely on some assumptions, such as the fixed produc...

Background Increasing air conditioner use for cooling indoor spaces has the potential to be a primary driver of global greenhouse gas emissions. Moving indoor air with residential fans can raise the temperature threshold at which air conditioning needs to be turned on to maintain the thermal comfort of building occupants. We investigate whether fan...

The COVID-19 pandemic demonstrated the vulnerability of tourism workers, but no detailed job loss figures are available that links tourism vulnerability with income inequality. This study evaluates how reduced international tourism consumption affects tourism employment and their income loss potential for 132 countries. This analysis shows that hig...

Sustainable development depends on decoupling economic growth from resource use. The material footprint indicator accounts for environmental pressure related to a country’s final demand. It measures material use across global supply-chain networks linking production and consumption. For this reason, it has been used as an indicator for two Sustaina...

Over a million plastic bottles are bought around the world every minute, 20,000 every second. While there is agreement that single-use plastics should be phased out, records of plastic pollution point in the opposite direction. Until the phasing-out of single-use plastics materialises, there is an immediate opportunity to mitigate the environmental...

When deciding on a country’s future energy policy, it is essential to accurately estimate the future generation mix and technology costs, as well as future generation site locations in electricity power grids. This estimate needs to allow for changing levels of demand and increasing levels of renewable energy supply, with both having high fluctuati...

Nitrogen is crucial for sustaining life. However, excessive reactive nitrogen (Nr) in the form of ammonia, nitrates, nitrogen oxides or nitrous oxides affects the quality of water, air and soil, resulting in human health risks. This study aims to assess the drivers of Nr emissions by analysing six determinants: nitrogen efficiency (Nr emissions per...

Background Understanding the relationship between sustainability and nutrients is important in devising healthy and sustainable diets. However, there are no prevailing methodologies to assess sustainability at the nutrient level. Objectives To examine and demonstrate the potential of integrating input-output analysis with nutritional geometry to l...

The IPCC Special Report on Global Warming of 1.5 °C highlights the potential for dietary shifts to reduce greenhouse gas emissions from livestock. Reductions in the consumption of terrestrial animal protein require increases in the consumption of other food categories, to maintain food security, balanced dietary patterns, and protein intake. Aquacu...

We introduce a cross-entropy (CE) indicator to quantify the extent to which two input–output tables or two tables with results based on input–output analysis differ from each other. Our work deploys a unique feature of the CE indicator: it can be decomposed, allowing for matrix comparisons at various levels within one coherent framework. To illustr...

Informed environmental-economic policy decisions require a solid understanding of the economy's biophysical basis. Global physical input-output tables (gPIOTs) collate a vast array of information on the world economy's physical structure and its interdependence with the environment, which can help to monitor progress toward a sustainable circular e...

Current commitments in nationally determined contributions (NDCs) are insufficient to remain within the 2-degree climate change limit agreed to in the Paris Agreement. The Intergovernmental Panel on Climate Change (IPCC) states that lifestyle changes are now necessary to stay within the limit. We reviewed a range of NDCs and national climate change...

Worldwide exposure to ambient PM2.5 causes over 4 million premature deaths annually. As most of these deaths are in developing countries, without internationally coordinated efforts this polarized situation will continue. As yet, however, no studies have quantified nation-to-nation consumer responsibility for global mortality due to both primary an...

China is responsible for a large proportion of the global material footprint. Cities are thought to be associated with most of natural resources consumption and negative impacts on the environment, especially in China, where rapid urbanization and industrial transformation has been observed over the past two decades. Cities usually source a major p...

China's middle-class cultivation plan has been put on the agenda. The demographic transformation process is likely to be accompanied by environmental changes. Different income groups have their own characteristics, exerting different degrees of pressure on the environment. Based on a multiregional input-output model, we analyse the spillover-feedba...

With the development of interregional trade, a potential disaster that happens in one place could cause enormous economic losses in distant areas. Timely and comprehensive post-disaster assessments play a significant role in guiding disaster recovery, and for reconstruction and planning for future disaster risk reduction. In this study, we evaluate...

Successful implementation of the Sustainable Development Goals (SDGs) requires world countries to account for actions that inadvertently generate negative impacts on other countries. These actions/effects are called 'spill-overs', and can hinder a country's SDG progress. In this work, we analyse negative social spillover effects, focussing specific...

Established climate mitigation scenarios assume continued economic growth in all countries, and reconcile this with the Paris targets by betting on speculative technological change. Post-growth approaches may make it easier to achieve rapid mitigation while improving social outcomes, and should be explored by climate modellers.

Industrial Ecology Virtual Laboratories (IELabs) enable the construction of national‐to‐local‐scale multi‐regional input–output (MRIO) models. These IELabs have been proven to be especially important for analyzing research questions that warrant sub‐national spatial detail. The field of industrial ecology has clearly progressed from the time of nat...

Climate change is causing a range of impacts on communities such as more frequent extreme weather, air pollution, changing distribution of infectious diseases, mental health impacts and others. The 2018 report of the Lancet Countdown on health and climate change concluded that "…climate change is the biggest global health threat of the 21st century...

1.5 °C scenarios reported by the Intergovernmental Panel on Climate Change (IPCC) rely on combinations of controversial negative emissions and unprecedented technological change, while assuming continued growth in gross domestic product (GDP). Thus far, the integrated assessment modelling community and the IPCC have neglected to consider degrowth s...

Pesticides are widely used to protect food production and meet global food demand but are also ubiquitous environmental pollutants, causing adverse effects on water quality, biodiversity and human health. Here we use a global database of pesticide applications and a spatially explicit environmental model to estimate the world geography of environme...

It has been observed that market failure has hampered the development of sustainable forest ecosystem services such as CO2 absorption and fixation, water retention, and biodiversity. One of the reasons for this is that the link between forest land use and the beneficiaries of that use has not been widely recognized or clearly established. To addres...

This paper explores the potential of a practical sustainability accounting roadmap that might contribute to transforming organisational accounting approaches to sustainability. The paper develops and evaluates an approach to input-output analysis, which combines existing financial accounting with publicly available national input-output data for sc...

Controversy exists regarding the scale of the impacts caused by fast fashion. This article aims to provide a robust basis for discussion about the geography, the scale and the temporal trends in the impacts of fast fashion because the globalisation of the fashion industry means original, peer-reviewed, quantitative assessments of the total impacts...

We investigate the development of stationary energy policy for the national and sub-national ecological footprint. Three carbon emission mitigation scenarios relating to the electricity sector (two different fuel mix scenarios and the rate of technological uptake) are explored. We find that the effectiveness of sub-national policy varies with globa...

Objective: To estimate the impact of reduced consumption of free sugars in line with World Health Organization recommendations, on sugar farmers globally. Methods: Using multiregion input-output analysis, we estimated the proportional impact on production volumes of a 1% reduction in free sugars consumption by the public. We extracted data on su...

Informed environmental-economic policy decisions require a solid understanding of the economy's biophysical basis. Global physical input-output tables (gPIOTs) collate a vast array of information on the world economy's physical structure and its interdependence with the environment. However, building gPIOTs requires dealing with mismatched and inco...

The COVID-19 pandemic is the single largest event in contemporary history in terms of the global restriction of mobility, with the majority of the world population experiencing various forms of “lockdown”. This phenomenon incurred increased amounts of teleworking and time spent at home, fewer trips to shops, closure of retail outlets selling non-es...

Electrical energy storage (EES) has the potential to facilitate the transition to renewable energy supply in the future as it brings flexibility into the electricity network. Uncertainties exist around regulation, commercial models, technology and cost but EES is recognized among experts as being part of the solution. This study offers an economic...

Objective To estimate the impact on sugar farmers globally of reduced consumption of free sugars, in line with World Health Organization recommendations. Methods Using multiregion input-output analysis, we estimated the proportional impact on production volumes of a 1% reduction in free sugars consumption by the public. We extracted data on sugar p...

For many arid countries, desalination is considered as the final possible option to ensure water availability. Although seawater desalination offers the utilisation of almost infinite water resources, the technology is associated with high costs, high energy consumption and thus high carbon emissions when using electricity from fossil sources. In o...

Because of the variability of wind and solar resources, high shares of wind and solar PV in power supply systems can lead to supply gaps during occasional low-resource periods. Due to their ability to meet demand in a short term, dispatchable renewable energy (RE) resources – biomass, concentrating solar power (CSP) and hydropower – can assist in m...

A major challenge for cities taking action on climate change is assessing and managing the contribution of urban consumption which triggers greenhouse gas (GHG) emissions outside city boundaries. Using a novel method of creating city‐level input–output tables, we present the first consistent, large‐scale, and global assessment of three‐scope GHG in...

The link between global ecosystem decline, trade, and human consumption suggests that trade-based biodiversity footprints should be regarded as a critical indicator of planetary impacts. Here we integrate a global input-output economic framework that encompasses global trade between 15909 sectors, with range and impact data on 10518 terrestrial pla...

On 3 April 2020, the Director-General of the WHO stated: “[COVID-19] is much more than a health crisis. We are all aware of the profound social and economic consequences of the pandemic (WHO, 2020)”. Such consequences are the result of counter-measures such as lockdowns, and world-wide reductions in production and consumption, amplified by cascadin...

Input–output analysis currently treats capital investment as exogenous to the inter-industry system despite capital goods being used further in production processes. Previous studies have applied the Leontief calculus to include impacts of capital in footprint calculations. Here, we adopt a supply-use approach to incorporating capital into footprin...

Purpose Consumption- and production-based accounting approaches for national greenhouse gas (GHG) emissions provide different insights to support climate policymaking. However, no study has yet comprehensively assessed the consumption-based GHG emissions of the entire New Zealand’s economy. This research, for the first time, quantified New Zealand’...

Background Health-care services are necessary for sustaining and improving human wellbeing, yet they have an environmental footprint that contributes to environment-related threats to human health. Previous studies have quantified the carbon emissions resulting from health care at a global level. We aimed to provide a global assessment of the wide-...

Small Island Developing States such as the Cook Islands are faced with a myriad of challenges due to their size and physical isolation. One solution that we explore is the effect local sustainable businesses would have in the Cook Islands. In be this study we analyze three different case studies organized into transport, beverages and pork manufact...

Small Pacific islands are highly dependent on diesel fuel imports to run diesel generators for their electricity needs. Diesel generators are less than 40% efficient and at least 60% of energy is wasted in the form of heat. A significant share of the electricity is consumed for running electric reefer containers that are employed by islanders for t...

Our current food systems are hampering efforts to meet the Sustainable Development Goals. Reshaping our food systems could have enormous co-benefits for our populations and planet. However, decision makers and experts are questioning whether it is possible to meet environmental, social and economic goals simultaneously, or whether tradeoffs are nec...

For over half a century, worldwide growth in affluence has continuously increased resource use and pollutant emissions far more rapidly than these have been reduced through better technology. The affluent citizens of the world are responsible for most environmental impacts and are central to any future prospect of retreating to safer environmental...

Many studies have concluded that the current global economy can transition from fossil fuels to be powered entirely by renewable energy. While supporting such transition, we critique analysis purporting to conclusively demonstrate feasibility. Deep uncertainties remain about whether renewables can maintain, let alone grow, the range and scale of en...

Deforestation can increase the transmission of malaria. Here, we build upon the existing link between malaria risk and deforestation by investigating how the global demand for commodities that increase deforestation can also increase malaria risk. We use a database of trade relationships to link the consumption of deforestation-implicated commoditi...