Stefan Pauliuk

Moving Toward the Circular Economy: The Role of Stocks in the Chinese Steel Cycle

As the worlds largest CO(2) emitter and steel producer, China has set the ambitious goal of establishing a circular economy which aims at reconciling economic development with environmental protection and sustainable resource use. This work applies dynamic material flow analysis to forecast production, recycling, and iron ore consumption in the Chinese steel cycle until 2100 by using steel services in terms of in-use stock per capita as driver of future development. The whole cycle is modeled to determine possible responses of the steel industry in light of the circular economy concept. If per-capita stock saturates at 8-12 tons as evidence from industrialized countries suggests, consumption may peak between 2015 and 2020, whereupon it is likely to drop by up to 40% until 2050. A slower growing in-use stock could mitigate this peak and hence reduce overcapacity in primary production. Old scrap supply will increase substantially and it could replace up to 80% of iron ore as resource for steel making by 2050. This would require advanced recycling technologies as manufacturers of machinery and transportation equipment would have to shift to secondary steel as well as new capacities in secondary production which could, however, make redundant already existing integrated steel plants.

The Roles of Energy and Material Efficiency in Meeting Steel Industry CO2 Targets

Identifying strategies for reducing greenhouse gas emissions from steel production requires a comprehensive model of the sector but previous work has either failed to consider the whole supply chain or considered only a subset of possible abatement options. In this work, a global mass flow analysis is combined with process emissions intensities to allow forecasts of future steel sector emissions under all abatement options. Scenario analysis shows that global capacity for primary steel production is already near to a peak and that if sectoral emissions are to be reduced by 50% by 2050, the last required blast furnace will be built by 2020. Emissions reduction targets cannot be met by energy and emissions efficiency alone, but deploying material efficiency provides sufficient extra abatement potential.

Carbon emissions of infrastructure development.

Identifying strategies for reconciling human development and climate change mitigation requires an adequate understanding of how infrastructures contribute to well-being and greenhouse gas emissions. While direct emissions from infrastructure use are well-known, information about indirect emissions from their construction is highly fragmented. Here, we estimated the carbon footprint of the existing global infrastructure stock in 2008, assuming current technologies, to be 122 (-20/+15) Gt CO2. The average per-capita carbon footprint of infrastructures in industrialized countries (53 (± 6) t CO2) was approximately 5 times larger that that of developing countries (10 (± 1) t CO2). A globalization of Western infrastructure stocks using current technologies would cause approximately 350 Gt CO2 from materials production, which corresponds to about 35-60% of the remaining carbon budget available until 2050 if the average temperature increase is to be limited to 2 °C, and could thus compromise the 2 °C target. A promising but poorly explored mitigation option is to build new settlements using less emissions-intensive materials, for example by urban design; however, this strategy is constrained by a lack of bottom-up data on material stocks in infrastructures. Infrastructure development must be considered in post-Kyoto climate change agreements if developing countries are to participate on a fair basis.

The Steel Scrap Age

Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

Dynamic Models of Fixed Capital Stocks and Their Application in Industrial Ecology

This is the pre-peer reviewed version of the following article: [FULL CITE], which has been published in final form at DOI: 10.1111/jiec.12149. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

Reconciling Sectoral Abatement Strategies with Global Climate Targets : The Case of the Chinese Passenger Vehicle Fleet

The IPCC Forth Assessment Report postulates that global warming can be limited to 2 °C by deploying technologies that are currently available or expected to be commercialized in the coming decades. However, neither specific technological pathways nor internationally binding reduction targets for different sectors or countries have been established yet. Using the passenger car stock in China as example we compute direct CO(2) emissions until 2050 depending on population, car utilization, and fuel efficiency and compare them to benchmarks derived by assuming even contribution of all sectors and a unitary global per capita emission quota. Compared to present car utilization in industrialized countries, massive deployment of prototypes of fuel efficient cars could reduce emissions by about 45%, and moderately lower car use could contribute with another 33%. Still, emissions remain about five times higher than the benchmark for the 2 °C global warming target. Therefore an extended analysis, including in particular low-carbon fuels and the impact of urban and transport planning on annual distance traveled and car ownership, should be considered. A cross-sectoral comparison could reveal whether other sectors could bear an overproportional reduction quota instead. The proposed model offers direct interfaces to material industries, fuel production, and scrap vehicle supply.

Solid Waste and the Circular Economy: A Global Analysis of Waste Treatment and Waste Footprints

Summary Detailed and comprehensive accounts of waste generation and treatment form the quantitative basis of designing and assessing policy instruments for a circular economy (CE). We present a harmonized multiregional solid waste account, covering 48 world regions, 11 types of solid waste, and 12 waste treatment processes for the year 2007. The account is part of the physical layer of EXIOBASE v2, a multiregional supply and use table. EXIOBASE v2 was used to build a waste-input-output model of the world economy to quantify the solid waste footprint of national consumption. The global amount of recorded solid waste generated in 2007 was approximately 3.2 Gt (gigatonnes1), of which 1 Gt was recycled or reused, 0.7 Gt was incinerated, gasified, composted, or used as aggregates, and 1.5 Gt was landfilled. Patterns of waste generation differ across countries, but a significant potential for closing material cycles exists in both high- and low-income countries. The European Union (EU), for example, needs to increase recycling by approximately 100 megatonnes per year (Mt/yr) and reduce landfilling by approximately 35 Mt/yr by 2030 to meet the targets set by the Action Plan for the Circular Economy. Solid waste footprints are strongly coupled with affluence, with income elasticities of around 1.3 for recycled waste, 2.2 for recovery waste, and 1.5 for landfilled waste, respectively. The EXIOBASE v2 solid waste account is based on statistics of recorded waste flows and therefore likely to underestimate actual waste flows.

Regional distribution and losses of end-of-life steel throughout multiple product life cycles—Insights from the global multiregional MaTrace model

Graphical abstract

Lifting Industrial Ecology Modeling to a New Level of Quality and Transparency: A Call for More Transparent Publications and a Collaborative Open Source Software Framework

Industrial ecology (IE) is a maturing scientific discipline. The field is becoming more data and computation intensive, which requires IE researchers to develop scientific software to tackle novel research questions. We review the current state of software programming and use in our field and find challenges regarding transparency, reproducibility, reusability, and ease of collaboration. Our response to that problem is fourfold: First, we propose how existing general principles for the development of good scientific software could be implemented in IE and related fields. Second, we argue that collaborating on open source software could make IE research more productive and increase its quality, and we present guidelines for the development and distribution of such software. Third, we call for stricter requirements regarding general access to the source code used to produce research results and scientific claims published in the IE literature. Fourth, we describe a set of open source modules for standard IE modeling tasks that represent our first attempt at turning our recommendations into practice. We introduce a Python toolbox for IE that includes the life cycle assessment (LCA) framework Brightway2, the ecospold2matrix module that parses unallocated data in ecospold format, the pySUT and pymrio modules for building and analyzing multiregion input‐output models and supply and use tables, and the dynamic_stock_model class for dynamic stock modeling. Widespread use of open access software can, at the same time, increase quality, transparency, and reproducibility of IE research.

Prospective Models of Society’s Future Metabolism: What Industrial Ecology Has to Contribute

Scientific assessment of sustainable development strategies provides decision-makers with quantitative information about the strategies’ potential effect. This assessment is often done by forward-looking or prospective computer models of society’s metabolism and the natural environment. Computer models in industrial ecology (IE) have advanced rapidly over the recent years, and now, a new family of prospective models is available to study the potential effect of sustainable development strategies at full scale.