Reduced carbon emission estimates from fossil fuel combustion and cement production in China

Journal name:
Nature
Volume:
524,
Pages:
335–338
Date published:
DOI:
doi:10.1038/nature14677
Received
Accepted
Published online

Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China1, 2. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China’s total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent1, 3, 4, 5. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China’s carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000–2012 than the value reported by China’s national statistics6, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change7, and that emissions from China’s cement production are 45 per cent less than recent estimates1, 4. Altogether, our revised estimate of China’s CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories1, 4, 8. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China’s cumulative carbon emissions1, 4. Our findings suggest that overestimation of China’s emissions in 2000–2013 may be larger than China’s estimated total forest sink in 1990–2007 (2.66 gigatonnes of carbon)9 or China’s land carbon sink in 2000–2009 (2.6 gigatonnes of carbon)10.

At a glance

Figures

  1. Total carbon content and production of coal mines.
    Figure 1: Total carbon content and production of coal mines.

    The inset shows the comparison between carbon content from 602 coal samples and 4,243 coal mines (R=0.59, P<0.001, n=104). Each dot in the inset indicates the average of carbon content from 602 coal samples and 4,243 coal mines in the same 1° by 1° grid. The nearly onetoone correlation indicates that samples and mines capture the same spatial variability of coal carbon content across China.

  2. Histograms of Chinese coal properties.
    Figure 2: Histograms of Chinese coal properties.

    a, b, Total carbon content of 4,243 coal mines (a) and 602 coal samples (b). Dashed lines show mean, and shading indicates 90% and 95% intervals. c, d, Net carbon content (c) and net heating values (d) of the 602 coal samples. Carbon content for coal mines (a) and samples (b) are significantly lower than IPCC values, which is mainly because of the lower net heating values of China’s coal (d); net carbon content is close to the IPCC value (c). e, f, Total moisture (e) and ash content (f) further proved the low quality of China’s coal, which in general has high ash content but low carbon content.

  3. Comparison of emission factors in 2012.
    Figure 3: Comparison of emission factors in 2012.

    IPCC: default value from IPCC guidelines for national emission inventories (1996, 2006)7, 11. NDRC: value reported by the NDRC (ref. 25). NC: China’s National Communication, which reported to the UNFCCC (2012 for value in 2005)8. All error bars are 2σ errors.

  4. Estimates of Chinese CO2 emissions 1990-2013.
    Figure 4: Estimates of Chinese CO2 emissions 1990–2013.

    Total carbon emissions from combustion of fossil fuels and manufacture of cement in China from different sources (International Energy Agency (IEA; sec, sectoral; ref, reference)3, Energy Information Administration (EIA; http://www.eia.gov/ and BP18 estimates do not include the emissions from cement production). The yellow dots are the numbers China reported to the UNFCCC in the years 1994 and 2005 (ref. 8). The redshaded area indicates the 95% uncertainty range of carbon emissions calculated by this study, assuming the emission factors during the period 1990–2013 are the same as those determined for 2012 in this study.

  5. Uncertainty distribution of Chinese CO2 emissions 1997-2012.
    Extended Data Fig. 1: Uncertainty distribution of Chinese CO2 emissions 1997–2012.

    Monte Carlo simulations of the Chinese carbon emissions based on a blended activity data set where national and provincial data are assigned equal probabilities (n=100,000). Chinese carbon emissions based on national energy activity data (EN) and provincial activity energy data (EP) in 2012 are shown on the right bar.

  6. Total fossil fuel energy consumption based upon national statistics, provincial statistics and calculations in this study.
    Extended Data Fig. 2: Total fossil fuel energy consumption based upon national statistics, provincial statistics and calculations in this study.
  7. Location of 4,243 coal mines with annual production and 602 coal samples.
    Extended Data Fig. 3: Location of 4,243 coal mines with annual production and 602 coal samples.

    The coal samples and mines are consistent with spatial distribution.

  8. Emission estimates of China/'s cement production by different sources.
    Extended Data Fig. 4: Emission estimates of China’s cement production by different sources.
  9. Growth rate of carbon emissions, based upon BP, EGDAR, IEA and calculations in this study, and industrial products.
    Extended Data Fig. 5: Growth rate of carbon emissions, based upon BP, EGDAR, IEA and calculations in this study, and industrial products.

    Industrial products comprise the production of cement, iron, steel and power generation. The emission trends calculated in this study are consistent with the trends of industrial production.

Tables

  1. Twenty-four emission inventories of fossil fuel combustion based on reported emission factors and fuel inventories in China.
    Extended Data Table 1: Twenty-four emission inventories of fossil fuel combustion based on reported emission factors and fuel inventories in China.

References

  1. Boden, T. A., Marland, G. & Andres, R. J. Global, Regional, and National Fossil-Fuel CO2 Emissions (Oak Ridge National Laboratory, US Department of Energy, 2013)
  2. Liu, Z. et al. A low-carbon road map for China. Nature 500, 143145 (2013)
  3. International Energy Agency. CO2 Emissions from Fuel Combustion (IEA, 2013)
  4. Olivier, J. G., Janssens-Maenhout, G. & Peters, J. A. Trends in Global CO2 Emissions: 2013 Report (PBL Netherlands Environmental Assessment Agency, 2013)
  5. Kurokawa, J. et al. Emissions of air pollutants and greenhouse gases over Asian regions during 2000–2008: Regional Emission inventory in ASia (REAS) version 2. Atmos. Chem. Phys. 13, 1101911058 (2013)
  6. National Bureau of Statistics of China. Chinese Energy Statistics Yearbook (China Statistics Press, 2013)
  7. Intergovernmental Panel on Climate Change. 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 2006)
  8. National Development and Reform Commission. Second National Communication on Climate Change of the People’s Republic of China (Department of Climate Change, 2012)
  9. Pan, Y. et al. A large and persistent carbon sink in the world’s forests. Science 333, 988993 (2011)
  10. Piao, S. et al. The carbon balance of terrestrial ecosystems in China. Nature 458, 10091013 (2009)
  11. Intergovernmental Panel on Climate Change. Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 1997)
  12. Gregg, J. S., Andres, R. J. & Marland, G. China: emissions pattern of the world leader in CO2 emissions from fossil fuel consumption and cement production. Geophys. Res. Lett. 35, L08806 (2008)
  13. Andres, R. J., Boden, T. A. & Higdon, D. A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission. Tellus B Chem. Phys. Meterol. 66, 23616 (2014)
  14. Fridley, D. Inventory of China's Energy-Related CO2 Emissions in 2008 (Lawrence Berkeley National Laboratory, 2011)
  15. Andres, R. J. et al. A synthesis of carbon dioxide emissions from fossil-fuel combustion. Biogeosciences 9, 18451871 (2012)
  16. Guan, D., Liu, Z., Geng, Y., Lindner, S. & Hubacek, K. The gigatonne gap in China’s carbon dioxide inventories. Nature Climate Change 2, 672675 (2012)
  17. Sinton, J. E. & Fridley, D. G. A guide to China’s energy statistics. J. Energ. Lit. 8, 2235 (2002)
  18. BP. BP Statistical Review of World Energy 2014 (BP, 2014)
  19. Zhao, Y., Nielsen, C. P. & McElroy, M. B. China’s CO2 emissions estimated from the bottom up: recent trends, spatial distributions, and quantification of uncertainties. Atmos. Environ. 59, 214223 (2012)
  20. Reuter, M. et al. Decreasing emissions of NOx relative to CO2 in East Asia inferred from satellite observations. Nature Geosci. 7, 792795 (2014)
  21. Lin, J.-T. & McElroy, M. Detection from space of a reduction in anthropogenic emissions of nitrogen oxides during the Chinese economic downturn. Atmos. Chem. Phys. 11, 81718188 (2011)
  22. National Bureau of Statistics. China Statistical Yearbook 1996–2014 (China Statistics Press, 2014)
  23. Hatch, J. R., Bullock, J. H. & Finkelman, R. B. Chemical Analyses Of Coal, Coal-Associated Rocks And Coal Combustion Products Collected For The National Coal Quality Inventory (USGS, 2006)
  24. Zhao, Y., Wang, S., Nielsen, C. P., Li, X. & Hao, J. Establishment of a database of emission factors for atmospheric pollutants from Chinese coal-fired power plants. Atmos. Environ. 44, 15151523 (2010)
  25. National Development and Reform Commission. Guidelines for China’s Provincial GHG Emission Inventories (NDRC, 2012)
  26. Peters, G., Weber, C. & Liu, J. Construction of Chinese Energy and Emissions Inventory (NTNU, 2006)
  27. China Cement Association. China Cement Almanac 2012–2013 (China Building Materials Press, 2014)
  28. Shen, L. et al. Factory-level measurements on CO2 emission factors of cement production in China. Renew. Sustain. Energy Rev. 34, 337349 (2014)
  29. Liu, M. et al. Refined estimate of China’s CO2 emissions in spatiotemporal distributions. Atmos. Chem. Phys. 13, 1087310882 (2013)
  30. Ke, J., McNeil, M., Price, L., Khanna, N. Z. & Zhou, N. Estimation of CO2 emissions from China’s cement production: methodologies and uncertainties. Energy Policy 57, 172181 (2013)
  31. Le Quéré, C. et al. Global carbon budget 2014. Earth Syst. Sci. Data Discuss. 7, 521610 (2014)
  32. Raupach, M. R. et al. Sharing a quota on cumulative carbon emissions. Nature Clim. Change 4, 873879 (2014)
  33. Liu, Z. et al. Climate policy: Steps to China's carbon peak. Nature 255, 279781 (2015)
  34. National Development and Reform Commission. The People’s Republic of China National Greenhouse Gas Inventory (China Environmental Science Press, 2007)
  35. The United Nations. Energy Statistics Database (United Nations Publications, 2010)
  36. Fridley, E. D. China Energy Databook—User Guide and Documentation, Version 7.0 (Lawrence Berkeley National Laboratory, 2008)
  37. Sinton, J. E. Accuracy and reliability of China’s energy statistics. China Econ. Rev. 12, 373383 (2001)
  38. Marland, G. Emissions accounting: China’s uncertain CO2 emissions. Nature Clim. Change 2, 645646 (2012)
  39. Liu, J. & Yang, H. China fights against statistical corruption. Science 325, 675 (2009)
  40. Holz, C. A. The quality of China’s GDP statistics. China Econ. Rev. 30, 309338 (2014)
  41. Rawski, T. G. What is happening to China’s GDP statistics? China Econ. Rev. 12, 347354 (2001)
  42. Tu, J. Industrial Organisation of the Chinese Coal Industry (Freeman Spogli Institute for International Studies, 2011)
  43. State Administration of Coal Mine Safety. China Coal Industry Yearbook (Coal Information Research Institute, 2013)

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Author information

Affiliations

  1. John F. Kennedy School of Government, Harvard University, Cambridge, Massachusetts 02138, USA

    • Zhu Liu
  2. Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China

    • Zhu Liu,
    • Steven J. Davis &
    • Fengming Xi
  3. Resnick Sustainability Institute, California Institute of Technology, Pasadena, California 91125, USA

    • Zhu Liu
  4. Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China

    • Dabo Guan,
    • Qiang Zhang,
    • Hongyan Zhao &
    • Chaopeng Hong
  5. School of International Development, University of East Anglia, Norwich NR4 7TJ, UK

    • Dabo Guan &
    • Yuan Li
  6. CAS Key Laboratory of Low-carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China

    • Wei Wei
  7. Department of Earth System Science, University of California, Irvine, California 92697, USA

    • Steven J. Davis
  8. Laboratoire des Sciences du Climat et de l’Environnement, CEA-CNRS-UVSQ, CE Orme des Merisiers, 91191 Gif sur Yvette Cedex, France

    • Philippe Ciais &
    • Shushi Peng
  9. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001, China

    • Jin Bai
  10. CNRS and UJF Grenoble 1, Laboratoire de Glaciologie et Geophysique de l’Environnement (LGGE, UMR5183), 38041 Grenoble, France

    • Shushi Peng
  11. Department of Geographical Sciences, University of Maryland, College Park, Maryland 20742, USA

    • Klaus Hubacek &
    • Kuishuang Feng
  12. Research Institute for Environment, Energy, and Economics, Appalachian State University, Boone, North Carolina 28608, USA

    • Gregg Marland
  13. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

    • Robert J. Andres &
    • Thomas A. Boden
  14. Cambridge Centre for Climate Change Mitigation Research, Department of Land Economy, University of Cambridge, 19 Silver Street, Cambridge CB3 9EP, UK

    • Douglas Crawford-Brown
  15. Laboratory for Climate and Ocean–Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China

    • Jintai Lin
  16. State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China

    • Chaopeng Hong &
    • Kebin He
  17. Center for International Climate and Environmental Research-Oslo (CICERO), N-0318 Oslo, Norway

    • Glen P. Peters
  18. CAS Key Laboratory of Pollution Ecology and Environmental Engineering, Chinese Academy of Sciences, Shenyang 110016, China

    • Fengming Xi
  19. School of Nature Conservation, Beijing Forestry University, Beijing 10083, China

    • Junguo Liu
  20. Ecosystems Services & Management Program, International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg, Austria

    • Junguo Liu
  21. School of Environmental Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, China

    • Junguo Liu
  22. State Key Laboratory of Pollution Control & Resource Reuse and School of the Environment, Nanjing University, Nanjing 210023, China

    • Yu Zhao
  23. Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland 20742-2425, USA

    • Ning Zeng
  24. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China

    • Ning Zeng

Contributions

Z.L. and D.G. designed the paper. Z.L. conceived the research. Z.L. provided the data from 4,243 coal mines. W.W. and J.B. provided the measurement data from 602 coal samples. S.J.D., J.B., Q.Z., R.J.A. and T.A.B. provided the reference data. Z.L., D.G., S.J.D., P.C., S.P., J.L., H.Z., C.H., Y.L. and Q.Z. performed the analysis. S.J.D., S.P., Z.L., H.Z. and K.F. drew the figures. All authors contributed to writing the paper.

Competing financial interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to:

Author details

Extended data figures and tables

Extended Data Figures

  1. Extended Data Figure 1: Uncertainty distribution of Chinese CO2 emissions 1997–2012. (143 KB)

    Monte Carlo simulations of the Chinese carbon emissions based on a blended activity data set where national and provincial data are assigned equal probabilities (n=100,000). Chinese carbon emissions based on national energy activity data (EN) and provincial activity energy data (EP) in 2012 are shown on the right bar.

  2. Extended Data Figure 2: Total fossil fuel energy consumption based upon national statistics, provincial statistics and calculations in this study. (145 KB)
  3. Extended Data Figure 3: Location of 4,243 coal mines with annual production and 602 coal samples. (173 KB)

    The coal samples and mines are consistent with spatial distribution.

  4. Extended Data Figure 4: Emission estimates of China’s cement production by different sources. (167 KB)
  5. Extended Data Figure 5: Growth rate of carbon emissions, based upon BP, EGDAR, IEA and calculations in this study, and industrial products. (207 KB)

    Industrial products comprise the production of cement, iron, steel and power generation. The emission trends calculated in this study are consistent with the trends of industrial production.

Extended Data Tables

  1. Extended Data Table 1: Twenty-four emission inventories of fossil fuel combustion based on reported emission factors and fuel inventories in China. (305 KB)

Supplementary information

PDF files

  1. Supplementary Information (2.1 MB)

    This file contains a detailed description of the Supplementary Data.

Excel files

  1. Supplementary Data (1.6 MB)

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Additional data