A. Grubler

Dynamics of energy technologies and global change

Technological choices largely determine the long-term characteristics of industrial society, including impacts on the natural environment. However, the treatment of technology in existing models that are used to project economic and environmental futures remains highly stylized. Based on work over two decades at IIASA, we present a useful typology for technology analysis and discuss methods that can be used to analyze the impact of technological changes on the global environment, especially global warming. Our focus is energy technologies, the main source of many atmospheric environmental problems. We show that much improved treatment of technology is possible with a combination of historical analysis and new modeling techniques. In the historical record, we identify characteristic &l such network e!ects yield high barriers to entry even for superior competitors. These simple observations allow three improvements to modeling of technological change and its consequences for global environmental change. One is that the replacement of long-lived infrastructures over time has also replaced the fuels that power the economy to yield progressively more energy per unit of carbon pollution } from coal to oil to gas. Such replacement has &d they also include endogenous generation of &s we show that doing so can yield projections with lessened environmental impacts without necessarily incurring negative e!ect on the economy. Arriving on that path by the year 2100 depends on intervening actions, such as incentives to promote greater diversity in technology and lower barriers to entry for new infrastructures that could accelerate historical trends of decarbonization. ( 1999 Elsevier Science Ltd. All rights reserved.

Identifying dangers in an uncertain climate

We need to research all the potential outcomes, not try to guess which is likeliest to occur.

Energy Pathways for Sustainable Development

Chapter 17 explores possible transformational pathways of the future global energy system with the overarching aim of assessing the technological feasibility as well as the economic implications of meeting a range of sustainability objectives simultaneously. As such, it aims at the integration across objectives, and thus goes beyond earlier assessments of the future energy system that have mostly focused on either specific topics or single objectives.

Long-term strategies for mitigating global warming

This special issue reviews technological options for mitigating carbon dioxide (CO2) emissions. The options analyzed include efficiency improvements, renewable energies, clean fossil and zero-carbon energy technologies, carbon sequestration and disposal, enhancement of natural carbon sinks (halting deforestation, afforestation, and other sink enhancement options), and geo-engineering measures to compensate for increases in CO2 concentrations. Reduction potentials, costs, and the relative contribution of individual options, as well as their limiting factors and possible timing of introduction and diffusion, are discussed. The study concludes with a discussion of methodological issues and of trade-offs and constraints for implementation strategies to mitigate anthropogenic sources of change in the global carbon cycle.

Future capacity growth of energy technologies: are scenarios consistent with historical evidence?

Future scenarios of the energy system under greenhouse gas emission constraints depict dramatic growth in a range of energy technologies. Technological growth dynamics observed historically provide a useful comparator for these future trajectories. We find that historical time series data reveal a consistent relationship between how much a technology’s cumulative installed capacity grows, and how long this growth takes. This relationship between extent (how much) and duration (for how long) is consistent across both energy supply and end-use technologies, and both established and emerging technologies. We then develop and test an approach for using this historical relationship to assess technological trajectories in future scenarios. Our approach for “learning from the past” contributes to the assessment and verification of integrated assessment and energy-economic models used to generate quantitative scenarios. Using data on power generation technologies from two such models, we also find a consistent extent - duration relationship across both technologies and scenarios. This relationship describes future low carbon technological growth in the power sector which appears to be conservative relative to what has been evidenced historically. Specifically, future extents of capacity growth are comparatively low given the lengthy time duration of that growth. We treat this finding with caution due to the low number of data points. Yet it remains counter-intuitive given the extremely rapid growth rates of certain low carbon technologies under stringent emission constraints. We explore possible reasons for the apparent scenario conservatism, and find parametric or structural conservatism in the underlying models to be one possible explanation.

Diffusion: Long-term patterns and discontinuities

The characteristic S-shaped diffusion pattern and the resulting rates of diffusion are a macroaggregate of an underlying complexity of adoption causes. Diffusion is therefore not a unary process. Instead, diffusion phenomena are probably best conceptualized as proceeding through various stages of a diffusion life cycle. In each of these stages the process is characterized by different market niches, different determinants of diffusion, and different relationships to other diffusion processes — both of a competitive and interdependent nature. Diffusion processes should therefore be analyzed based on multivariate (i.e., considering an innovation diffusion case not in isolation) and multiattribute (i.e., using a number of measures to describe diffusion trajectories and developing comprehensive vectors of driving variables) approaches.

Transitions in Energy Use

Patterns of energy use have changed dramatically since the onset of the industrial revolution in terms of both energy quantities and energy quality. These changing patterns of energy use, where energy quantities and quality interact in numerous important ways, are referred to in this article as energy transitions and are described from a historical perspective as well as through future scenarios. Far from being completed, many of these transitions are continuing to unfold in industrial and developing countries alike. Energy transitions are described here in terms of three major interdependent characteristics: quantities (growths in amounts of energy harnessed and used), structure (which types of energy forms are harnessed, processed, and delivered to the final consumers as well as where these activities take place), and quality (the energetic and environmental characteristics of the various forms of energy used).

Decarbonizing the global energy system

Abstract The study analyzes the long-term decarbonization of the global energy system, i.e., the decrease of the carbon emissions per unit of primary energy. Decarbonization appears as a continuous and persistent trend throughout the world, albeit occurring at very slow rates of approximately 0.3% per year. The study also discusses driving forces of the associated structural changes in energy systems such as technological change. Decarbonization also occurs at the level of energy end use and trends for final energy are shown. The quest for higher flexibility, convenience, and cleanliness of energy services demanded by consumers leads to decarbonization trends in final energy that are more pronounced that those of the upstream energy sector. The study concludes with a discussion of the implications for long-term scenarios of energy-environment interactions suggesting that decarbonization and its driving forces may still be insufficiently captured by most models and scenarios of the long-term evolution of the energy system.

Diffusion of Technologies and Social Behavior

The diffusion of innovations is at the core of the dynamic processes that underlie social, economic, and technological change. Diffusion phenomena are not limited to the spread of new process technologies and the market penetration of new products but extend also to changes in the forms of social organization and transformations in the social fabric and cultural traits. This book is the outcome of the diffusion of the concept of diffusion as a fundamental process in society. Originating from biology, diffusion research is now carried out in many disciplines including economics, geography, history, technological change, sociology, and management science. The book illustrates the progress that has been made in understanding the nature of diffusion processes and their underlying driving forces. The contributions by leading scholars provide a novel interdisciplinary perspective and span a wide range of modeling and empirical research backgrounds.

Urban Energy Systems

Executive Summary More than 50% of the global population already lives in urban settlements and urban areas are projected to absorb almost all the global population growth to 2050, amounting to some additional three billion people. Over the next decades the increase in rural population in many developing countries will be overshadowed by population flows to cities. Rural populations globally are expected to peak at a level of 3.5 billion people by around 2020 and decline thereafter, albeit with heterogeneous regional trends. This adds urgency in addressing rural energy access, but our common future will be predominantly urban. Most of urban growth will continue to occur in small-to medium-sized urban centers. Growth in these smaller cities poses serious policy challenges, especially in the developing world. In small cities, data and information to guide policy are largely absent, local resources to tackle development challenges are limited, and governance and institutional capacities are weak, requiring serious efforts in capacity building, novel applications of remote sensing, information, and decision support techniques, and new institutional partnerships. While ‘megacities’ with more than 10 million inhabitants have distinctive challenges, their contribution to global urban growth will remain comparatively small. Energy-wise, the world is already predominantly urban. This assessment estimates that between 60–80% of final energy use globally is urban, with a central estimate of 75%. Applying national energy (or GHG inventory) reporting formats to the urban scale and to urban administrative boundaries is often referred to as a ‘production’ accounting approach and underlies the above GEA estimate.