| 英文摘要: | Impetus to expand electricity access in developing nations is urgent1. Yet aspirations to provide universal access to electricity are often considered potentially conflicting with efforts to mitigate climate change2. How much newly electrified, largely poor, households raise emissions, however, remains uncertain. Results from a first retrospective analysis show that improvements in household electricity access contributed 3–4% of national emissions growth in India over the past three decades. Emissions from both the direct and indirect electricity use of more than 650 million people connected since 1981 accounted for 11–25% of Indian emissions growth or, on average, a rise of 0.008–0.018 tons of CO2 per person per year between 1981 and 2011. Although this is a marginal share of global emissions, it does not detract from the importance for developing countries to start reducing the carbon intensities of their electricity generation to ensure sustainable development and avoid future carbon lock-in3, 4. Significant ancillary benefits for air quality, health, energy security and efficiency may also make this attractive for reasons other than climate mitigation alone5, 6. Access to electricity services is fundamental to development, as it enables improvements in human quality of life. Recent empirical studies have quantified a range of benefits of better electricity access and reliability for income and employment generation, gender equity, health, entrepreneurship and education7, 8, 9. People without electricity are denied the most basic services, from street lighting that can improve safety at night, to mobile phone charging that is vital for communication. Tasks such as milling and grinding cereals that ordinarily require the push of a button can, for the unelectrified, take days of human labour and drudgery, trapping them in subsistence living. Despite general recognition of the critical importance of electricity, India today hosts the world’s largest population without access to it. According to the 2011 Census, a third of all households in the country, or almost 400 million people, live without this basic service10. More than 90% of the unelectrified live in rural areas, and for many that are connected electricity supply remains highly unreliable9. Providing universal and reliable access to affordable electricity is essential. Yet significant barriers exist to electrifying rural areas in most developing nations, including India11, 12. Overcoming these barriers requires strengthening policy and institutional frameworks and additional investments13. Providing a minimum amount of basic electricity access universally is an urgent short-term imperative. However, ultimately the objective is to extend the benefits of electricity services so as to sustain escape from poverty, and provide more equitable opportunities for livelihood creation and long-term economic development. Providing energy that enables this broader development, beyond meeting just basic household needs, could lead to larger increases in energy demand14. Finding sustainable pathways to meet this growing demand remains a pressing challenge for much of the developing world. Nations facing the biggest challenge in providing modern energy access have historically contributed the least to climate change15. However, this is unlikely to continue as, in many emerging nations, large populations without access to modern energy services already coexist with populations living affluent lifestyles and having large carbon footprints. This has given rise to growing concern about the emissions implications of better access to modern energy in the developing world. Understanding the contribution to historical emissions growth of changes in electricity access can provide insights for avoiding any potential future trade-offs between universal electrification and climate change mitigation goals. Existing evidence suggests that meeting the energy needs of the poor is unlikely to contribute significantly to global greenhouse gas emissions16, 17. Recent studies that have assessed the emissions implications of eradicating energy poverty globally or achieving universal modern energy access for cooking and electricity use in homes have done so prospectively. They conclude that these efforts would contribute only marginally to greenhouse gas emissions over the next decades. This work, for the first time, analyses the emissions implications of better access retrospectively, using historical data from India. India is an ideal case for such an analysis because of its large unelectrified population, the scale of electrification it has already achieved, and its growing energy demand and emissions. In 2011, India emitted 1,745 MtCO2 yr−1 according to the International Energy Agency (IEA; ref. 18). The electricity sector’s contribution to total national CO2 emissions rose from less than 30% in 1981 to more than 45% by 2011, increasing more than tenfold to 795 MtCO2 yr−1 in 2011. Over the past three decades, household electricity use has also contributed a growing share of total national CO2 emissions, accounting for 20% of electricity sector emissions in 2011. Between 1981 and 2011, household electricity access improved from 26% to 67% according to census sources10, or from 25% to 74% according to national surveys19. According to data for the same period from India’s Central Electricity Authority (CEA), the share of households connected increased from 19% to 71% (ref. 20). In other words, more than 650 million Indians gained access to electricity over these thirty years. Two-thirds of all households that were connected to electricity during this period were rural. Average annual electricity use among those connected remains very low, despite more than doubling from about 400 kWh per household in 1981 to more than 900 kWh per household in 2011 (Fig. 1). By comparison in 2011, the average household consumption of electricity in China was about 1,200 kWh, whereas in the USA it was more than 10,000 kWh.
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