Energy transitions or additions?

Is an energy transition currently in progress, where renewable energy sources are replacing fossil fuels? Previous changes in the proportion of energy produced by various sources – such as in the nineteenth century when coal surpassed biomass in providing the largest share of the global energy supply and in the twentieth century when petroleum overtook coal – could more accurately be characterized as energy additions rather than transitions. In both cases, the use of the older energy source continued to grow, despite rapid growth in the new source. Evidence from contemporary trends in energy production likewise suggest that as renewable energy sources compose a larger share of overall energy production, they are not replacing fossil fuels but are rather expanding the overall amount of energy that is produced. We argue that although it is reasonable to expect that renewables will come to provide a growing share of the global energy supply, it is misleading to characterize this growth in renewable energy as a “transition” and that doing so could inhibit the implementation of meaningful policies aimed at reducing fossil fuel use. Given the severity of the threat posed by anthropogenic climate change, which is in large part driven by fossil fuel combustion, it is becoming widely recognized that societies need a transition in how they produce and consume energy. Expressing a view common among energy analysts, Michelle Grayson [1: S133] asserts in the introduction to a special supplement to Nature focused on energy transitions, “The transition from fossil fuels is well underway. Each year sees an increase in the amount of electricity generated from renewable sources....” Some recent data on global energy consumption and carbon emissions appear to support the claim that we may be in the midst of an energy transition. Over the past decade, non-hydro renewable energy has been growing rapidly, averaging an annual rate of 16.2% [2]. Additionally, global carbon emissions, most of which come from fossil fuels, were approximately flat from 2014 to 2016 [2]. The primary reason for the leveling-off of carbon emissions is that the global consumption of coal (the most carbon intensive fossil fuel) declined by about 1% each year over this period [2]. However, belying the 2014–2016 decline in coal consumption, the historical pattern of changes in energy systems suggests that asserting a “transition from fossil fuels” [1: S133, our emphasis] at the global level is underway may be premature and potentially misleading. In fact, optimism based on the recent decline in coal consumption and stabilization of carbon emissions may be an example of “recency bias” [3], where overly focusing on the most recent data and failing to take into account longer-term patterns biases the assessment of the likelihood of various potential future trajectories. A key point we highlight here is that there is a fundamental difference between (1) developing the infrastructure for and expanding the production of a new energy source (what we call an energy addition) and (2) a transition away from (i.e., a genuine decline in the use of) more established energy sources. The phrase “energy transition” typically implies that both of these processes are taking place, such that established energy sources are being replaced by new ones, not just supplemented by them. So as to avoid confusion and sharpen analytic acuity, we argue that “energy transition” should be used only when there is an actual move away from one source to another, not just when https://doi.org/10.1016/j.erss.2019.01.008 Received 16 November 2018; Received in revised form 9 January 2019; Accepted 10 January 2019 ⁎ Corresponding author. E-mail addresses: rfyork@uoregon.edu (R. York), sbell33@vt.edu (S.E. Bell). Energy Research & Social Science 51 (2019) 40–43 Available online 16 January 2019 2214-6296/ © 2019 Elsevier Ltd. All rights reserved. T a new source expands (which is simply an “energy addition”). The addition of new energy sources (e.g., wind farms, solar installations) to the global system is clearly underway. However, it is not yet clear that societies are decisively moving away from fossil fuels; therefore, it may not be the case that we are in the midst of a transition, at least in the full sense of the word. History shows us that although new energy sources have been successfully added to the global energy system and have grown to provide a large share of the overall energy supply, it is entirely unprecedented for these additions to cause a sustained decline in the use of established energy sources. Thus, calling the addition of renewables to the energy supply an “energy transition” may not only be misleading, but also potentially counter-productive, as such claims may provide the false impression of imminent reductions in carbon emissions and thereby suppress efforts to bring about a genuine transition away from fossil fuels. In fact, despite widespread optimism about the decline in coal consumption and the leveling of carbon emissions between 2014 and 2016, the pattern reverted to its historical norm in 2017, when carbon emissions grew by 1.6% and coal consumption by 1% [2]. Why, then, is the claim of an “energy transition” so prevalent? Indeed, there is a growing body of research focused on studying energy transitions both historical and contemporary, which accepts that a number of transitions have occurred in the past [e.g., 4–9]. However, a common mistake made in analyses documenting so-called energy transitions is centering the argument on the proportion of the energy supply that is generated from various sources. In Fig. 1, we present the percentage of global energy consumption from various sources from 1800 to 2017 based on data provided by Smil [6: 155], which we supplemented with data from BP [2] to calculate the 2017 values . An important note is that in these data, biofuel is a broader category than is used in many data sources in that it includes estimated use of wood, agricultural waste, and other biomass that is not used for electricity generation and that does not enter the market. In addition, we do not show energy from solar or wind, since these are so low they would hardly register on the graph – e.g., despite rapid growth in recent years, wind and solar combined provided only about 2% of the global energy supply in 2017 [2]. Graphics very similar to Fig. 1 (although only ranging from the years 1800 to 2000) are presented by others to illustrate previous changes in global energy production [e.g., [8]: 206; [10]: 396]. These authors characterize some of these historical changes as transitions. At a first glance, our Fig. 1 also seems to suggest, as Smil [10: 395–396] explains, that a “transition” from biofuels (mostly wood) to coal occurred during the nineteenth century, a “transition” from coal to oil occurred in the mid-twentieth century, and, now, a “transition” to natural gas is currently in progress. But are these shifts actually transitions in the sense of moving away from one energy source to another? If we examine the absolute quantity, instead of the proportion, of total energy from various sources, we get a different impression from that given by Fig. 1. Fig. 2 presents total global energy consumption in exajoules from various sources from 1800 to 2017 (based on the same data sources used to make Fig. 1). Note that Sovacool [8] and Smil [6,10], while presenting the proportional composition of the global energy supply (like in Fig. 1), do not focus their discussions on or graphically present the absolute quantity of energy (like Fig. 2) in their assessments of purported energy transitions. As can be seen clearly in Fig. 2, historically, no established energy source has undergone a sustained decline with the addition of a new energy source. Rather, consumption of all energy sources has typically grown, a trend that has been maintained for over two centuries. Of course, there have been some periods of slight decline in the consumption of some sources, such as with coal between 1990 and 2000 (due largely to the collapse of the economies of former Soviet Republics and other Eastern Bloc nations) and with biofuels toward the end of the nineteenth century. However, in all cases, growth has returned, dominating the historical trajectory of each energy source. Although Fig. 1 appears to demonstrate there was a decline in biofuels and coal once new energy sources were introduced, Fig. 2 corrects this inaccurate impression. As Fig. 2 makes clear, biofuel consumption is currently more than double what it was in 1800, and coal use is likewise more than double what it was when oil became the dominant energy source in the 1950s. The historical pattern presented in Fig. 2 suggests that past energy “transitions” could be more accurately described as energy additions. There were not transitions away from established energy sources, but rather additions of new energy sources on top of established ones. In each of the major historical shifts in energy-source proportions illustrated in Fig. 1 (biofuels to coal, coal to oil, and oil to natural gas), even as consumption of the newly introduced energy source grew explosively, consumption of the older energy source continued to grow as well (as Fig. 2 shows). In effect, the addition of newer energy sources has simply allowed for further growth in overall energy consumption, rather than serving as a replacement for older sources. A growing body of cross-national research examining how the addition of new energy sources affects established sources further supports our argument. For example, in an analysis of data for most nations of the world from 1960 to 2009, York [11] found that, controlling for a variety of economic and demographic factors, growth in non-fossil fuel energy only had a very modest effect on curbing fossil fuel use, where it took between four and thirteen units of non-fossil energy to displace one unit of fossil en