Adaptive Networks of Socio-metabolic Flows

The goal of this flagship initiative is to study the flows of energy and raw materials that support human societies (denoted as social metabolism) across scales from global to urban.

Speaker: Helga Weisz

Team members: Peter-Paul Pichler, Idil Ires, Kira Vinke, Ingram Jaccard, Camille Belmin

Background

Social metabolism, the exchange of energy and materials across social and environmental systems, constitutes the physical basis of societies. The magnitude and composition of the social metabolism varies significantly in time and between societies. The industrial metabolism, the specific socio-metabolic regime of industrial societies, has a pertinent role in providing human welfare but also negatively impacts the Earth’s climate and ecosystems. The added value of a socio-metabolic perspective lies in its ability to link, both conceptually and in quantitative empirical ways, the analysis of human history and modern society to global environmental change research, including climate mitigation, impact and adaptation analysis.

The social metabolism describes the exchange of energy and materials across social and environmental systems.

The social metabolism describes the exchange of energy and materials across social and environmental systems.

Methods

We use a wide variety of methods to study the energy and material use of socities across time and space. Statistical modeling and advanced tools like environmentally extended multi-regional input-output modeling are equally part of our research as are complex and adaptive network analysis, agent-based modeling and machine learning. To date these latter methods are rarely applied to socio-metabolic research, although they are particularly well suited to unravel fundamental and relevant aspects of the structure, evolution and vulnerability of the physical supply chains in current socio-metabolic systems In addition, the application of agent based techniques bears a high potential to address the as yet severely under-researched question of how the physical metabolic dimension of human societies is structurally coupled to socio-economic dynamics on various scales.

Research Topics

Urban Metabolism: Reducing Urban Greenhouse Gas Footprints

Cities are economically open systems that depend on goods and services imported from national and global markets to satisfy their material and energy requirements. Greenhouse Gas (GHG) footprints are thus a highly relevant metric for urban climate change mitigation since they not only include direct emissions from urban consumption activities, but also upstream emissions, i.e. emissions that occur along the global production chain of the goods and services purchased by local consumers. This complementary approach to territorially-focused emission accounting has added critical nuance to the debate on climate change mitigation by highlighting the responsibility of consumers in a globalized economy. Yet, city officials are largely either unaware of their upstream emissions or doubtful about their ability to count and control them.

Conceptual comparison between territorial GHG emission accounting (a) and the GHG footprint (b). Territorial emissions include the entirety of emissions that occur within the city boundary. These are direct emissions from production (goods & services, transport) and final consumption (households, government, gross fixed capital formation). Because they also include urban production for exports, territorial emissions are often indicative of the economic structure of a city (e.g. in the presence of heavy industry). The GHG footprint, instead, puts the focus on consumption within the city boundary. In this study it includes direct and upstream GHG emissions from household consumption. The former occur within the city boundary (e.g. heating and private transport), the latter may occur anywhere in the world (including within the city) and require analysing the entire supply chain of urban consumption. The GHG footprint is indicative of the consumption pattern of urban households (source).

Conceptual comparison between territorial GHG emission accounting (a) and the GHG footprint (b). Territorial emissions include the entirety of emissions that occur within the city boundary. These are direct emissions from production (goods & services, transport) and final consumption (households, government, gross fixed capital formation). Because they also include urban production for exports, territorial emissions are often indicative of the economic structure of a city (e.g. in the presence of heavy industry). The GHG footprint, instead, puts the focus on consumption within the city boundary. In this study it includes direct and upstream GHG emissions from household consumption. The former occur within the city boundary (e.g. heating and private transport), the latter may occur anywhere in the world (including within the city) and require analysing the entire supply chain of urban consumption. The GHG footprint is indicative of the consumption pattern of urban households (source).

The study provides the first internationally comparable GHG footprints for four cities (Berlin, Delhi NCT, Mexico City, and New York metropolitan area) applying a consistent method that can be extended to other global cities using available data. We show that upstream emissions from urban household consumption are in the same order of magnitude as cities’ overall territorial emissions and that local policy leverage to reduce upstream emissions is larger than typically assumed.

The global reach of urban GHG footprints. The four maps show the spatial distribution of the cities’ non-domestic upstream household GHG emissions. (source).

The global reach of urban GHG footprints. The four maps show the spatial distribution of the cities’ non-domestic upstream household GHG emissions. (source).

Revolutions in energy input and material cycling in Earth history and human history

Major revolutions in energy capture have occurred in both Earth and human history, with each transition resulting in higher energy input, altered material cycles and major consequences for the internal organization of the respective systems. In Earth history, we identify the origin of anoxygenic photosynthesis, the origin of oxygenic photosynthesis, and land colonization by eukaryotic photosynthesizers as step changes in free energy input to the biosphere. In human history we focus on the Palaeolithic use of fire, the Neolithic revolution to farming, and the Industrial revolution as step changes in free energy input to human societies. In each case we try to quantify the resulting increase in energy input, and discuss the consequences for material cycling and for biological and social organization. For most of human history, energy use by humans was but a tiny fraction of the overall energy input to the biosphere, as would be expected for any heterotrophic species. However, the industrial revolution gave humans the capacity to push energy inputs towards planetary scales and by the end of the 20th century human energy use had reached a magnitude comparable to the biosphere.

Energy capture in the biosphere and human society. Dates indicate beginning of the respective revolution, energy estimates are given for dates where energy regimes had matured (source).

Energy capture in the biosphere and human society. Dates indicate beginning of the respective revolution, energy estimates are given for dates where energy regimes had matured (source).

By distinguishing world regions and income brackets we show the unequal distribution in energy and material use among contemporary humans. Looking ahead, a prospective sustainability revolution will require scaling up new renewable and decarbonized energy technologies and the development of much more efficient material recycling systems – thus creating a more autotrophic social metabolism. Such a transition must also anticipate a level of social organization that can implement the changes in energy input and material cycling without losing the large achievements in standard of living and individual liberation associated with industrial societies.

Year 2000 (a) material and (b) energy use per capita, and (c) total population by World Bank income groups (source).

Year 2000 (a) material and (b) energy use per capita, and (c) total population by World Bank income groups (source).

Global Trade and Material Flows

Global production sharing, the rise of emerging economies, and the great trade collapse following the global financial crisis have deeply altered the structure of North-South trade. We analyze the deep reorganization of North-South commodity flows over the two decades between 1995 and 2014 in monetary volume and physical quantity. We find that the traditional narrative of the South providing cheap raw materials to the North while the North exports high value-added manufactures to the South is no longer valid. In fact, South-North trade surpasses North-South trade in unit-price, and the majority of raw materials are imported by the South. The trends leading to this current structure of North-South trade have existed prior to the global financial crisis but were substantially accelerated in the great trade collapse of 2008-2009. The slow growth of trade volume after 2011 stands in stark contrast to uninhibited growth in global trade quantity chiefly due to growing raw material imports of the South. We suggest that more emphasis on quantity data to complement purely monetary analyses of trade are increasingly indispensable to understanding the economic and non-economic effects of trade in areas such as climate change, public health and biodiversity loss.

Global trade network 1995-2014 (volume in current USD). Hierarchical clustering of countries by income levels and into North and South. Arc size is proportional to total trade volume (imports and exports) and arc color indicates trade balance (red = monetary trade deficit; blue = monetary trade surplus). Lines between countries represent trade flows from blue (exporter) to red (importer) and are proportional to trade volume.

Global trade network 1995-2014 (Quantity in kg). Hierarchical clustering of countries by income levels and into North and South. Arc size is proportional to total trade quantity (imports and exports) and arc color indicates trade balance (red = monetary trade surplus; blue = monetary trade deficit). Lines between countries represent trade flows from blue (exporter) to red (importer) and are proportional to trade quantity.

Ongoing third party funded projects

ClimBHealth April 2015 – March 2016 Contact: Helga Weisz

Carbon Footprints April 2017 – March 2019 Contact: Helga Weisz

IIASA Verein Verein zur Förderung des internationalen Instituts für angewandte Systemanalyse e.V. April 2015 – December 2017, Funded by: BMBF, PT DLR Contact: Helga Weisz

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