Abstract

Stabilizing greenhouse gas (GHG) emissions from croplands as agricultural demand grows is a critical component of climate change mitigation1,2,3. Emissions intensity metrics—including carbon dioxide equivalent emissions per kilocalorie produced (‘production intensity’)—can highlight regions, management practices, and crops as potential foci for mitigation4,5,6,7. Yet the spatial and crop-wise distribution of emissions intensity has been uncertain. Here, we develop global crop-specific circa 2000 estimates of GHG emissions and GHG intensity in high spatial detail, reporting the effects of rice paddy management, peatland draining, and nitrogen (N) fertilizer on CH4, CO2 and N2O emissions. Global mean production intensity is 0.16 Mg CO2e M kcal−1, yet certain cropping practices contribute disproportionately to emissions. Peatland drainage (3.7 Mg CO2e M kcal−1)—concentrated in Europe and Indonesia—accounts for 32% of these cropland emissions despite peatlands producing just 1.1% of total crop kilocalories. Methane emissions from rice (0.58 Mg CO2e M kcal-1), a crucial food staple supplying 15% of total crop kilocalories, contribute 48% of cropland emissions, with outsized production intensity in Vietnam. In contrast, N2O emissions from N fertilizer application (0.033 Mg CO2e M kcal−1) generate only 20% of cropland emissions. We find that current total GHG emissions are largely unrelated to production intensity across crops and countries. Climate mitigation policies should therefore be directed to locations where crops have both high emissions and high intensities.

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References

  1. 1.

    et al. Solutions for a cultivated plane. Nature 478, 337–342 (2011).

  2. 2.

    et al. Climate-smart agriculture for food security. Nat. Clim. Change 4, 1068–1072 (2014).

  3. 3.

    , , & Global food demand and the sustainable intensification of agriculture. Proc. Natl Acad. Sci. USA 108, 20260–20264 (2011).

  4. 4.

    & High-yield maize with large net energy yield and small global warming intensity. Proc. Natl Acad. Sci. USA 109, 1074–1079 (2012).

  5. 5.

    , , , & Towards an agronomic assessment of N2O emissions: a case study for arable crops. Eur. J. Soil Sci. 61, 903–913 (2010).

  6. 6.

    , , , & An agronomic assessment of greenhouse gas emissions from major cereal crops. Glob. Change Biol. 18, 194–209 (2012).

  7. 7.

    et al. Trading carbon for food: Global comparison of carbon stocks vs. crop yields on agricultural land. Proc. Natl Acad. Sci. USA 107, 19645–19648 (2010).

  8. 8.

    , & Climate change and food systems. Ann. Rev. Environ. Resour. 37, 195–222 (2012).

  9. 9.

    et al. Carbon emissions from land use and land-cover change. Biogeosciences 9, 5125–5142 (2012).

  10. 10.

    , , , & Linking policy on climate and food. Science 331, 1013–1014 (2011).

  11. 11.

    FAOSTAT Online Statistical Service (Food and Agriculture Organization (FAO), 2016);

  12. 12.

    et al. The contribution of agriculture, forestry and other land use activities to global warming, 1990–2012. Glob. Change Biol. 21, 2655–2660 (2015).

  13. 13.

    et al. Sustainable intensification in agriculture: premises and policies. Science 341, 33–34 (2013).

  14. 14.

    et al. Impacts of cropping practices on yield-scaled greenhouse gas emissions from rice fields in China: A meta-analysis. Agr. Ecosyst. Environ. 164, 220–228 (2013).

  15. 15.

    et al. Producing more grain with lower environmental costs. Nature 514, 486–489 (2014).

  16. 16.

    et al. Spatially explicit estimates of N2O emissions from croplands suggest climate mitigation opportunities from improved fertilizer management. Glob. Change Biol. 22, 3383–3394 (2016).

  17. 17.

    , , & Global estimations of the inventory and mitigation potential of methane emissions from rice cultivation conducted using the 2006 Intergovernmental Panel on Climate Change Guidelines. Glob. Biogeochem. Cycles 23, GB2002 (2009).

  18. 18.

    IPCC: Summary for policymakers. In Climate Change 2007: The Physical Science Basis (eds Solomon, S. et al.) (Cambridge Univ. Press, 2007).

  19. 19.

    Trends in global rice consumption. Rice Today 12, 44–45 (2013).

  20. 20.

    IPCC 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Prepared by the National Greenhouse Gas Inventories Programme (eds Eggleston, H. S., Buendia, L., Miwa, K., Ngara, T. & Tanabe, K.) (Institute for Global Environmental Strategies, 2006).

  21. 21.

    et al. Peatlands in the Earth’s 21st century climate system. Environ. Rev. 19, 371–396 (2011).

  22. 22.

    , , & Methods for attributing land-use emissions to products. Carbon Manage. 5, 233–245 (2014).

  23. 23.

    et al. Global nutrition. Metrics for land-scarce agriculture. Science 349, 238–240 (2015).

  24. 24.

    , , & Redefining agricultural yields: from tonnes to people nourished per hectare. Environ. Res. Lett. 8, 034015 (2013).

  25. 25.

    et al. Increasing homogeneity in global food supplies and the implications for food security. Proc. Natl Acad. Sci. USA 111, 4001–4006 (2014).

  26. 26.

    et al. Leverage points for improving global food security and the environment. Science 345, 325–328 (2014).

  27. 27.

    et al. Managing nitrogen for sustainable development. Nature 528, 51–59 (2015).

  28. 28.

    et al. Closing yield gaps through nutrient and water management. Nature 490, 254–257 (2012).

  29. 29.

    et al. Yield-scaled global warming potential of annual nitrous oxide and methane emissions from continuously flooded rice in response to nitrogen input. Agr. Ecosyst. Environ. 177, 10–20 (2013).

  30. 30.

    et al. Designing a sustainable diet. Science 350, 165–166 (2015).

  31. 31.

    , & Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Glob. Biogeochem. Cycles 22, GB1022 (2008).

  32. 32.

    , , & Farming the planet: 1. Geographic distribution of global agricultural lands in the year 2000. Glob. Biogeochem. Cycles 22, GB1003 (2008).

  33. 33.

    IPCC 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands (eds Hiraishi, T. et al.) (IPCC, 2014).

  34. 34.

    et al. Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems. Proc. Natl Acad. Sci. USA 110, 20888–20893 (2013).

  35. 35.

    et al. Global Livestock Production Systems (FAO, International Livestock Research Institute (ILRI), 2011).

  36. 36.

    , & A process-based model for methane emission from flooded rice paddy systems. Ecol. Model. 205, 475–491 (2007).

  37. 37.

    Global Estimation of Monthly Irrigated and Rainfed Crop Areas on a 5 Arc-minute Grid PhD thesis, Univ. Frankfurt (2011)

  38. 38.

    AQUASTAT (FAO, 2015);

  39. 39.

    et al. Reduced methane emissions from large-scale changes in water management of China’s rice paddies during 1980–2000. Geophys. Res. Lett. 29, 1972 (2002)

  40. 40.

    Asia Least-cost Greenhouse Gas Abatement Strategy (ALGAS) (Asian Development Bank, Global Environment Facility and United Nations Development Program, 1998)

  41. 41.

    , , , & Wetting and Drying: Reducing Greenhouse Gas Emissions and Saving Water from Rice Production (World Resources Institute, 2014)

  42. 42.

    , , & Statistical analysis of the major variables controlling methane emission from rice fields. Glob. Change Biol. 11, 1131–1141 (2005)

  43. 43.

    & Rice Area by Type of Culture: South, Southeast, and East Asia, A Revised and Updated Data Base (International Rice Research Institute, 1997)

  44. 44.

    & Influence of organic-matter incorporation on the methane emission from a wetland rice field. Glob. Biogeochem. Cycles 9, 11–22 (1995)

  45. 45.

    , , , & Chapter 3 crop residue management for lowland rice-based cropping systems in Asia. Adv. Agron. 98, 117–199 (2008)

  46. 46.

    et al. Residue burning in rice-wheat cropping system: causes and implications. Curr. Sci. 87, 1713–1717 (2004)

  47. 47.

    , & Why do farmers burn rice residue? Examining farmers’ choices in Punjab, Pakistan. Land Use Policy 47, 448–458 (2015)

  48. 48.

    & An assessment of biofuel use and burning of agricultural waste in the developing world. Glob. Biogeochem. Cycles 17, 1095 (2003)

  49. 49.

    , & Bottom-up estimate of biomass burning in mainland China. Atmos. Environ. 40, 5262–5273 (2006)

  50. 50.

    Harmonized World Soil Database V 1.2 (FAO, IIASA, SRIC, ISSCAS and JRC, 2012);

  51. 51.

    The Global Peatland CO2 Picture: Peatland Status and Drainage Related Emissions in all Countries of the World 35 (Wetlands International, 2009)

  52. 52.

    , & Global and regional importance of the tropical peatland carbon pool. Glob. Change Biol. 17, 798–818 (2011)

  53. 53.

    Global Peat Resources 359 (International Peat Society, 1996)

  54. 54.

    Wise Use of Mires and Peatlands 304 (International Mire Conservation Group and International Peat Society, 2002)

  55. 55.

    & Diffusion GHG fluxes at tropical peatland drainage canal water surfaces. Suo 63, 93–105 (2012)

  56. 56.

    , , , & Nitrous oxide emissions from soils: how well do we understand the processes and their controls? Phil. Trans. R. Soc. 368, 20130122 (2013)

  57. 57.

    & N2O and NO emission from agricultural fields and soils under natural vegetation: summarizing available measurement data and modeling of global annual emissions. Nutr. Cycl. Agroecosyst. 74, 207–228 (2006)

  58. 58.

    et al. Closing the global N2O budget: nitrous oxide emissions through the agricultural nitrogen cycle. Nutr. Cycl. Agroecosyst. 52, 225–248 (1998)

  59. 59.

    The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860. Nat. Geosci. 2, 659–662 (2009)

  60. 60.

    , & Quantifying uncertainties in N2O emission due to N fertilizer application in cultivated areas. PLoS ONE 7, e50950 (2012)

  61. 61.

    , & Global metaanalysis of the nonlinear response of soil nitrous oxide (N2O) emissions to fertilizer nitrogen. Proc. Natl Acad. Sci. USA 111, 9199–9204 (2014)

  62. 62.

    , , , & Evaluation of emission factors for indirect N2O emission due to nitrogen leaching in agro-ecosystems. Geophys. Res. Lett. 32, L03403 (2005)

  63. 63.

    , , , & Very high resolution interpolated climate surfaces for global land areas. Int J. Climatol. 25, 1965–1978 (2005)

  64. 64.

    , , & Climate change mitigation: a spatial analysis of global land suitability for clean development mechanism afforestation and reforestation. Agric. Ecosyst. Environ. 126, 67–80 (2008)

  65. 65.

    et al. Trees and Water: Smallholder Agroforestry on Irrigated Lands in Northern India (International Water Management Institute, 2007)

  66. 66.

    ISRIC-WISE Derived Soil Properties on a 5 by 5 Arc-minutes Global Grid V 1.2 52 (ISRIC, 2012)

  67. 67.

    , & MIRCA200 - Global monthly irrigated and rainfed crop areas around the year 2000: A new high-resolution data set for agricultural and hydrological modeling. Glob. Biogeochem. Cycles 24, GB1011 (2010)

  68. 68.

    et al. Rethinking agricultural trade relationships in an era of globalization. BioScience 65, 275–289 (2015)

  69. 69.

    et al. Mind the gap: how do climate and agricultural management explain the ‘yield gap’ of croplands around the world? Glob. Ecol. Biogeogr. 19, 769–782 (2010)

  70. 70.

    et al. Integrated crop water management might sustainably halve the global food gap. Environ. Res. Lett. 11, 025002 (2016)

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Acknowledgements

We thank J. Foley for conversations conceptualizing this project. P. Engstrom, H. Rodrigues, D. Makowski, M. Ogg, S. Seibert and J. van de Steeg assisted with methods and data development. The Gordon and Betty Moore Foundation provided primary research funding, with additional support from the University of Minnesota Institute on the Environment, USDA National Institute of Food and Agriculture Hatch project HAW01136-H, managed by the College of Tropical Agriculture and Human Resources (K.M.C.), USDA Agriculture and Food Research Initiative fellowship 2016-67012-25208 (N.D.M.), NSF Hydrological Sciences grant 1521210 (N.D.M.), and the Belmont Forum/FACCE-JPI-funded DEVIL project NE/M021327/1 (J.S.G., M.H. and P.C.W.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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Affiliations

  1. Institute on the Environment, University of Minnesota, Saint Paul, Minnesota 55108, USA

    • Kimberly M. Carlson
    • , James S. Gerber
    • , Graham K. MacDonald
    • , Kate A. Brauman
    • , Christine S. O’Connell
    • , Justin A. Johnson
    •  & Paul C. West
  2. Department of Natural Resources and Environmental Management, University of Hawai’i, Honolulu, Hawai’i 96822, USA

    • Kimberly M. Carlson
  3. Department of Earth and Planetary Sciences, Harvard University, Harvard, Massachusetts 02138, USA

    • Nathaniel D. Mueller
  4. Department of Organismic and Evolutionary Biology, Harvard University, Harvard, Massachusetts 02138, USA

    • Nathaniel D. Mueller
  5. Commonwealth Scientific and Industrial Research Organization (CSIRO), St Lucia, Queensland 4067, Australia

    • Mario Herrero
  6. Department of Geography, McGill University, Montreal, Quebec H3A 0B9, Canada

    • Graham K. MacDonald
  7. Ecosystem Services and Management Program, International Institute for Applied Systems Analysis, Laxenburg, Austria

    • Petr Havlik
  8. Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720, USA

    • Christine S. O’Connell
  9. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA

    • Sassan Saatchi

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Contributions

K.M.C., P.C.W. and J.S.G. conceived the project. K.M.C., J.S.G., N.D.M., M.H., P.H., G.K.M. and K.A.B. provided new data and/or methods. K.M.C. and J.S.G. carried out modelling and analysis. All authors participated in writing the manuscript.

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The authors declare no competing financial interests.

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Correspondence to Kimberly M. Carlson.

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DOI

https://doi.org/10.1038/nclimate3158

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