China’s water–energy nexus: greenhouse-gas emissions from groundwater use for agriculture

China is the world’s largest emitter of greenhouse gases (GHGs) and the agricultural sector in China is responsible for 17‐20% of annual emissions and 62% of total freshwater use. Groundwater abstraction in China has increased rapidly from 10 km 3 yr 1 in the 1950s to more than 100 km 3 yr 1 in the 2000s, such that roughly 70% of the irrigated area in northern China is now groundwater-fed. Pumping of water for irrigation is one of the most energy consuming on-farm processes; however, to date this source of GHG emissions in China and elsewhere has been relatively neglected. We derive the first detailed estimate of GHG emissions from groundwater pumping for irrigation in China, using extensive village survey data from 11 provinces, broadly representative of the situation during the mid-2000s. The 11 provinces cover roughly half of China’s irrigated cropland and we upscale to the national level using government statistics for the remaining 20 provinces. Our results show emissions of 33.1 MtCO2e, just over half a per cent of the national total. Groundwater abstraction represents an important source of GHG emissions that has been rapidly increasing and which at present is largely unregulated. Water scarcity in China is already driving policies to improve water conservation. These results suggest that significant potential exists to promote the co-benefits of water and energy saving in order to meet national planning targets.

[1]  John Paxton,et al.  Republic of China , 1978 .

[2]  Peter Fraenkel,et al.  Water lifting devices , 1986 .

[3]  Shantanu Dixit,et al.  Agricultural pumping efficiency in India: the role of standards , 1996 .

[4]  T. Shah Sustaining Asia's groundwater boom: an overview of issues and evidence , 2003 .

[5]  Tushaar Shah,et al.  Energy-irrigation nexus in South Asia: improving groundwater conservation and power sector viability , 2003 .

[6]  Jikun Huang,et al.  China'S Agricultural Water Policy Reforms: Increasing Investment, Resolving Conflicts, And Revising Incentives , 2003 .

[7]  Zhaoyin Wang,et al.  Interbasin transfer projects and their implications: A China case study , 2003 .

[8]  R. Lal,et al.  Carbon emission from farm operations. , 2004, Environment international.

[9]  Tara C. Kandpal,et al.  Renewable energy technologies for irrigation water pumping in India: projected levels of dissemination, energy delivery and investment requirements using available diffusion models , 2005 .

[10]  Jikun Huang,et al.  Privatization of tubewells in North China: Determinants and impacts on irrigated area, productivity and the water table , 2006 .

[11]  Scott Rozelle,et al.  Agriculture and groundwater development in northern China: trends, institutional responses, and policy options , 2007 .

[12]  Junliang Zhang Barriers to water markets in the Heihe River basin in northwest China , 2007 .

[13]  Scott Rozelle,et al.  Water saving technology and saving water in China , 2007 .

[14]  F. Kahrl,et al.  China's water-energy nexus , 2008 .

[15]  Hubert H. G. Savenije,et al.  Food consumption patterns and their effect on water requirement in China , 2008 .

[16]  Pricing China's irrigation water , 2008 .

[17]  Scott Rozelle,et al.  Water management institutional reform: A representative look at northern China , 2009 .

[18]  Tushaar Shah,et al.  Climate change and groundwater: India’s opportunities for mitigation and adaptation , 2009 .

[19]  T. Maraseni,et al.  Energy and water tradeoffs in enhancing food security: a selective international assessment , 2009 .

[20]  Ju Hui,et al.  Future cereal production in China: The interaction of climate change, water availability and socio-economic scenarios , 2009 .

[21]  R. Robertson,et al.  Greenhouse gas mitigation: issues for Indian agriculture. , 2009 .

[22]  P. Döll Vulnerability to the impact of climate change on renewable groundwater resources: a global-scale assessment , 2009 .

[23]  Jikun Huang,et al.  Understanding the Water Crisis in Northern China: What the Government and Farmers are Doing , 2009 .

[24]  Pute Wu,et al.  Impact of climate change and irrigation technology advancement on agricultural water use in China , 2010 .

[25]  Andrew J. Challinor,et al.  Increased crop failure due to climate change: assessing adaptation options using models and socio-economic data for wheat in China , 2010 .

[26]  Jane Qiu,et al.  China drought highlights future climate threats , 2010, Nature.

[27]  D. Conway,et al.  Greenhouse-gas emissions from energy use in the water sector , 2011 .

[28]  Jamie Pittock National Climate Change Policies and Sustainable Water Management: Conflicts and Synergies , 2011 .

[29]  D. Conway,et al.  Effects of climate variability and change on Chinese agriculture: A review , 2011 .

[30]  Y. Wada,et al.  Assessment of transboundary aquifers of the world—vulnerability arising from human water use , 2013 .

[31]  C. Scott Electricity for groundwater use: constraints and opportunities for adaptive response to climate change , 2013 .

[32]  David Yates,et al.  The influence of future electricity mix alternatives on southwestern US water resources , 2013 .

[33]  T. Sang,et al.  Potential productivity of the Miscanthus energy crop in the Loess Plateau of China under climate change , 2013 .