Thomas Wiedmann

UNSW Sydney | UNSW · School of Civil and Environmental Engineering

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...

There is an urgent need to accelerate progress on the Sustainable Development Goals (SDGs) and recent research has identified six critical transformations. However, studies are yet to demonstrate how these transformations could be practically accelerated in a national context and what their combined effects would be. Here we deploy integrated syste...

The penetration rates of both electric vehicles (EVs) and distributed energy resources (DERs) have been increasing rapidly as appealing options to address the global problems of carbon emissions and fuel supply issues. However, uncoordinated EV charging activities and DER generation result in operational challenges for power distribution systems. T...

Transitioning to net-zero greenhouse gas (GHG) emissions by 2050 is becoming increasingly urgent, requiring accelerated efforts to decarbonise all economic sectors, including transport, a growing emissions source. A transition to battery electric vehicles (BEV) would accelerate the decarbonisation of road transport and provide other benefits. But i...

Transitioning to passenger battery electric vehicles (BEV) can mitigate climate change impacts of road transportation. We develop a novel BEV policy model, nesting it within a national-scale macroeconomic system dynamics model (iSDG-Australia) to simulate a suite of policy pathways. We model combinations of infrastructure support and subsidies, whi...

Today, more than 700 cities worldwide have made net-zero pledges. Managing these bold targets, however, is not easy given the complexity of urban systems. Although holistic mitigation efforts are vital, individual sectors are likely to face their own challenges and require tailor-made solutions. This Voices asks: what are the challenges and opportu...

City-level CO2 emissions inventories are foundational for supporting the EU's decarbonization goals. Inventories are essential for priority setting and for estimating impacts from the decarbonization transition. Here we present a new CO2 emissions inventory for all 116572 municipal and local-government units in Europe, containing 108000 cities at t...

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...

Seeking to meet sustainability targets, cities are promoting a number of circular economy initiatives. Whether or not these actions help cities to approach sustainable resource management is often unclear. To identify, prioritize and monitor resource-efficient strategies, cities can look for targets and indicators among the Sustainable Development...

Achieving net zero operational and embodied greenhouse gas (GHG) emissions in the built environment is recognised in Australia and globally as a key strategy to address climate change and achieve the United Nations Sustainable Development Goals (SDGs). However, gaps in the knowledge remain regarding potential national pathways to achieve this outco...

Decoupling economic growth from resource use and emissions is a precondition to stay within planetary boundaries. Some countries have achieved a reduction in their production-based emissions in the past decade. However, the decline in PBE has often been achieved via outsourcing of emissions to other countries, which may lead to higher emissions glo...

Passenger motor vehicle transport is a significant and growing emissions source contributing to climate change. Switching from internal combustion engines to electric vehicles (EV) would significantly reduce most countries’ emissions, but for many consumers perceived barriers deter EV adoption. Consequently, government policies designed to incentiv...

City-level CO2 emissions inventories are foundational for supporting the EU’s decarbonization goals. Inventories are essential for priority setting and for estimating impacts from the decarbonization transition. Here we present a new CO2 emissions inventory for 116,572 municipal and local government units in Europe. The inventory spatially disaggre...

Communicating the finiteness of the Earth system at sub-global scales is necessary to guide human activities within a safe operating space. Despite the numerous efforts committed to downscaling planetary boundaries (PBs) at multiple scales, neither top-down nor bottom-up approaches adequately account for the spatial heterogeneity and integrity of l...

This study focused on understanding what sector-region combinations could be targeted to reduce the total city water footprint? We used multi-regional input-output analysis of direct and virtual water, across major Australian cities and their supporting regions. The key novelty of this study is the high spatial resolution policy-relevant sub-sector...

Global greenhouse gas emissions can be traced to five economic sectors: energy, industry, buildings, transport and AFOLU (agriculture, forestry and other land uses). In this topical review we synthesize the literature to explain recent trends in global and regional emissions in each of these sectors. To contextualise our review, we present estimate...

The idea of revisiting the biophysical limits of human life on planet Earth has gained renewed momentum in the Anthropocene. The planetary boundaries (PBs) framework has emerged as a strong guardrail concept, even though its capacity to inform the development of absolute sustainability assessments and realistic policies remains unclear. In this pap...

Slavery is more prevalent today than at any point in human history. Society's heightened scrutiny and new government policy is forcing businesses and nations to act in lieu of reputational, financial, and legal repercussions. However, slavery hides within complex supply chains, making it difficult to identify instances of human exploitation. This s...

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...

Cities are recognised as central to determining the sustainability of human development. However, assessment concepts that are able to ascertain whether or not a city is sustainable are only just emerging. Here we review literature since the Sustainable Development Goals (SDGs) were agreed in 2015 and identify three strands of scientific inquiry an...

Cities are a key target in the global quest for sustainability and are increasingly acting independently to take the lead in sustainability initiatives. To truly achieve sustainability, cities need to ensure that their consumption is compatible with absolute sustainability and validate achievements from a perspective that includes transboundary imp...

Actions to reduce greenhouse gas emissions are required from all actors. Adopting plug-in electric vehicles (EV) would reduce light motor vehicle travel emissions, a significant and rising emissions source. To encourage EV uptake, many governments have implemented policies which may be less effective than desired. Using New Zealand as a case study,...

Non-technical summary The Sustainable Development Goals (SDGs) provide an integrated and ambitious roadmap for sustainable development by 2030. National implementation will be crucial and there is an urgent need to understand the scale and pace of transformations to achieve the goals. There is also concern that achieving socio-economic objectives w...

The sustainable development goals (SDGs) provide a framework of goals, targets, and indicators designed to guide national implementation of sustainable development to 2030. Several aspects of the framework are challenging, including its complex and integrated scope and transformational character. A range of approaches developed in the sustainabilit...

Modelling frameworks that aim to support policymakers in deriving effective measures to reduce environmental impacts should provide both: quantitative information on locally occurring consumption patterns and production systems as well as assessment of policy scenario outcomes. Regionalised models that can deliver on these aims are emerging, but ar...

Recent papers argue that the energy return on energy invested (EROI) for renewable electricity technologies and systems may be so low that the transition from fossil fuelled to renewable electricity may displace investment in other important economic sectors. For the case of large-scale electricity supply, we draw upon insights from Net Energy Anal...

Given the key role of households in driving global emissions and resource use, a change in their consumption behaviours towards more sustainable levels is essential to reduce worldwide adverse environmental impacts. Thereby, focusing on cities is especially important because of today's large share of the global population living in cities and becau...

The former consensus on a link between energy consumption and improved well-being of a country has been scrutinized by scholars for decades and is, succinctly, for the time being a contested thesis. Until the 1970s the relation of energy to well-being was defined as linearly proportional, and in a later period still as an increasing logarithmic fun...

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...

This study reviewed nexus researches to synthesize and discuss the insights, methodological practices, and future outlook of water-related energy assessment of the food system. For the first time, the study assessed: (i) the trends and drivers of water-related energy research in different countries, (ii) how water-related energy in the food system...

As the critical link between individual building and city, precinct represents an important scale for urban planning, at which low-carbon strategies for urban built environment can be tested and measured. However, previous studies often failed to assess the life cycle greenhouse gas (GHG) emissions from the urban precincts comprehensively and relia...

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...

Despite calls for large-scale reductions in material use and efforts to initiate a “circular economy” that promotes recycling and reuse, a limited decoupling between overall resource extraction and economic growth has been historically found. This is particularly true if resource use is measured with the life-cycle or consumption-based material foo...

The water planetary boundary (PB) has attracted wide academic attention but empirical water footprint research that accommodates local biophysical boundaries remains scarce. Here we develop two novel quantitative footprint indicators, the water exceedance footprint and the surplus water footprint. The first measures the amount of excessive water wi...

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...

Consumption-based carbon footprint (CBCF) assessments have become increasingly important in studying the drivers of climate change from a consumer perspective. A wide range of studies and approaches for CBCF have been presented, yet a systematic and interpretative synopsis of the literature is missing. We present a comprehensive review of more than...

Transforming China’s economic growth pattern from investment-driven to consumption-driven can significantly change global CO2 emissions. This study is the first to analyse the impacts of changes in China’s saving rates on global CO2 emissions both theoretically and empirically. Here, we show that the increase in the saving rates of Chinese regions...

A peer-to-peer sharing approach for the accommodation sector such as Airbnb has been suggested as a more environmental sustainable alternative to conventional forms of accommodation services. This study evaluates the carbon footprint of Airbnb hosts in Sydney. The Airbnb platform and its hosts, together generate direct and indirect carbon footprint...

There is building consensus that non-state actors have the potential to drive more ambitious action towards climate targets than governments, thus driving the necessary transition to ensure that humanity remains within a safe operating space. These bottom-up mitigation activities, however, require individual targets on both direct and indirect (ups...

The Sustainable Development Goals (SDGs) combine complex interlinkages, future uncertainty and transformational change. Recent studies highlight that trade-offs between SDG targets may undermine achievement of the goals. Significant gaps remain in scenario frameworks and modelling capabilities. We develop a novel approach nesting national SDG scena...

Cities play an important role in controlling climate change. Previous ‘city-scale studies’ have investigated consumption-based emission accounting for demand-side mitigation analysis. However, to date very few studies have presented income-based emissions accounting for supply-side mitigation strategies at the level of an urban agglomeration. To fi...

While traditional value engineering (VE) is primarily driven by cost saving, this study aims to comprehensively and reliably investigating the impact of traditional VE on the embodied greenhouse gas (GHG) emissions in the Australian built environment. An Australian-specific hybrid life cycle assessment (LCA) is developed and applied to a mixed-use...

A major challenge with ‘decarbonising’ urban development is how life-cycle carbon signatures of different urban forms can be methodically defined, quantitatively assessed, and effectively employed for low-carbon living. This chapter presents two CRC tools which interrogate the whole-of-life carbon emissions of all built forms, distributed energy te...

Background: Current climate change mitigation policies, including the Paris Agreement, are based on territorial greenhouse gas (GHG) accounting. This neglects the understanding of GHG emissions embodied in trade. As a solution, consumption-based accounting (CBA) that reveals the lifecycle emissions, including transboundary flows, is gaining support...

This chapter aims to increase awareness related to the assessment of embodied greenhouse gas emissions (GHGE) of the built environment in Australia—a critical step to achieve meaningful emissions reduction. A summary of existing methods, data, tools, guidance and gaps in quantifying embodied GHGE in the Australian built environment is provided. A q...

Carbon accounting results for the same city can differ due to differences in protocols, methods and data sources. A critical review of these differences and the connection among them can help to bridge our knowledge between university-based researchers and protocol practitioners in accounting and taking further mitigation actions. The purpose of th...

The Sustainable Development Goals (SDGs) provide an integrated, evidence-based framework of targets and indicators to support national planning and reporting. For countries to begin implementation of the SDGs, it is critical to build the evidence base for action. The integrated nature of the SDG targets means that progress towards one target is als...

Understanding carbon emissions embodied in trade is an important prerequisite for the effective formulation of climate mitigation policies. Based on input–output analysis and panel regression models, this study proposes a multi-step forecasting procedure to simulate carbon emissions embodied in bilateral trade. We calculate carbon emissions embodie...

The idea of measuring humanity's footprint against planetary boundaries has attracted wide academic attention but methods to implement the theory in sustainability accounting remain underexplored. To help nations take collective actions to stay within a safe operating space, footprinting approaches need to be revised to accommodate biophysical limi...

Hybrid life cycle assessment (LCA) has been developed for almost 40 years, but its applications are still limited to certain products/industries. This study endeavors to expand the accessibility of hybrid LCA from specialists to practitioners by developing a streamlined and semi-automated hybrid LCA data compilation routine in an input–output virtu...

Companies increasingly need detailed information on global impacts related to their products and services. This article describes a quantitative analytical approach that supports a better understanding of value-chain wide corporate sustainability performance. We use an extended multi-regional input-output model to analyse the global supply chains o...

Traditional consumption-based greenhouse gas emissions accounting attributed the gap between consumption-based and production-based emissions to international trade. Yet few attempts have analyzed the temporal deviation between current emissions and future consumption, which can be explained through changes in capital stock. Here we develop a dynam...

The global Sustainable Development Goals (SDGs) commenced in 2016 and provide an evidence-based framework for sustainable development planning and programming until 2030. There is emerging international practice and a growing catalogue of related reviews, assessments, guidelines and publications. While the expert community is clearly emphasising th...

This note presents a method to decompose life cycle inventories derived from integrated and mixed-unit hybrid life cycle assessment. The approach extends the decomposition method described by Wiedmann (Econ Struct 6:11, 2017. https://doi.org/10.1186/s40008-017-0072-0) by differentiating between impacts from industries, products and processes. The m...

The 28 states of the European Union are addressing considerable effort to reduce their current national energy consumption levels. A new environmental and socially low impact energy system, based on energy consumption reductions, an increase in energy efficiency and reductions of emissions shifting to renewable energy generation are established in...

The construction industry contributes around 18% of greenhouse gas emissions, 40% of depletion of natural resources, and 25% of wastes globally. To reduce these impacts, construction industries can adopt low-carbon alternatives for construction materials and waste minimisation strategies, including the recycling of construction and demolition waste...

Too much fertiliser in agriculture affects rivers and oceans at large scale. But it turns out that a surprising variety of non-food products is also to blame for impacts on water bodies worldwide.

The use of global, multiregional input‐output (MRIO) analysis for consumption‐based (footprint) accounting has expanded significantly over the last decade. Most of the global studies on environmental and social impacts associated with consumption or embodied in international trade would have been impossible without the rapid development of extended...

Globalization has led to an increasing geospatial separation of production and consumption, and, as a consequence, to an unprecedented displacement of environmental and social impacts through international trade. A large proportion of total global impacts can be associated with trade, and the trend is rising. Advances in global multi-region input-o...

Our submission to the Australian Senate Inquiry into the SDGs. We highlight areas where Australia is lagging behind, and strongly advocate for clear, measurable, realistic and time-bound national targets for Australia across all 17 goals.