| 英文摘要: | Energy use is not only crucial for economic development, but is also the main driver of greenhouse-gas emissions. Developing countries can reduce emissions and thrive only if economic growth is disentangled from energy-related emissions. Although possible in theory, the required energy-system transformation would impose considerable costs on developing nations. Developed countries could bear those costs fully, but policy design should avoid a possible 'climate rent curse', that is, a negative impact of financial inflows on recipients' economies. Mitigation measures could meet further resistance because of adverse distributional impacts as well as political economy reasons. Hence, drastically re-orienting development paths towards low-carbon growth in developing countries is not very realistic. Efforts should rather focus on 'feasible mitigation actions' such as fossil-fuel subsidy reform, decentralized modern energy and fuel switching in the power sector.
Today's developed countries account for the largest share of global greenhouse-gas (GHG) emissions accumulated in the atmosphere. However, recent years have witnessed a rapid increase in developing countries' emissions, most prominently in China, which became the world's largest emitter in 2006. China's energy-related CO2 emissions per capita (7.1 t), even though still below the Organisation for Economic Co-operation and Development (OECD) average, almost reached the European Union (EU-27) average of 7.4 t in 20121. If other developing countries follow China's carbon-intensive growth pattern, ambitious climate stabilization targets — such as the target to limit warming to 2°C above pre-industrial levels, agreed by the world community — are likely to become infeasible, even if industrialized countries were to drastically reduce their emissions2. Analyses with large-scale integrated assessment models often conclude that mitigation costs for developing countries are relatively moderate3. Some recent studies have highlighted the potential positive effects of climate measures on economic growth4, 5, 6 and the associated promise to create new economic dynamism by means of a 'green industrial revolution'7. Despite these optimistic assessments of the possibility to re-orient growth paths towards 'low-carbon development'8, this Perspective argues that — although possible in theory — it is fraught with considerable obstacles in practice due to the central role that fossil fuels have played and continue to play for economic development. The remainder of this Perspective is organized as follows. First, we discuss the historic relationship between economic growth, energy use and CO2 emissions in detail. The second part highlights major challenges to low-carbon transitions in developing countries, concluding that we need to be cautious in what can be expected with regard to low-carbon development there. Third, we discuss feasible mitigation actions, focusing on subsidy reform, decentralized modern energy access for rural areas and fuel switching in the power sector.
Socioeconomic development in the past has been closely correlated to energy use9, 10. As fossil fuels have traditionally constituted the major source of energy, there is also a close correlation between human development and GHG emissions11. No country has managed to achieve high levels of economic development without having crossed a threshold in final energy consumption of approximately 40 GJ per capita12, 13. Only one-quarter of these energy needs can be explained by subsistence needs such as cooking or heating14; an important part of the threshold can be explained by the energy needed to build up physical capital stocks, for example, infrastructure13, 15. Even though per capita emissions in developing countries generally remain below the OECD average, they have been catching up fast, in particular in China. Not only for China, but also for other newly industrializing countries, economic growth is clearly identified as the main driver of rising CO2 emissions, especially for the 2000s16. A significant share of these emissions is released for the production of goods and services that are finally consumed in developed countries17, 18. However, observed flows of emissions embodied in trade cannot be interpreted as a sign of 'outsourcing' of emissions, and it seems likely that developing countries' emissions would have experienced a sharp increase even without trade with industrialized countries19. This trend of rising emissions in developing countries is reinforced by a global 'renaissance of coal' that has led to an increasing carbonization of the global energy system16. This implies that the historical relationship between economic growth and energy use, which is dominated by fossil fuels, also seems to apply to countries that have only recently started to industrialize and which seem to replicate the patterns of energy use and emissions observed in the past in today's developed countries — albeit at an accelerated pace20. This is illustrated in Fig. 1, which shows per capita CO2 emissions against the log of per capita gross domestic product (GDP) (the log is chosen to make dynamics at low-income levels visible). It is remarkable that this relationship is very similar for most countries. For instance, China's income–emissions trajectory very closely tracks the historical emissions of Korea, Japan and France at the same income levels. The heavy reliance on fossil fuels is, of course, related to their low cost (if we ignore their negative climate and environmental externalities, such as emissions and air pollution), wide availability and versatility to supply different energy needs in different sectors21, 22.
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