Assessment and Mitigation of Greenhouse Gas Emissions from Groundwater Irrigation

Irrigation with groundwater consumes considerable energy as well as water resources across the world. Using a case study from Indian Punjab, this article emphasizes how a continued and massive use of groundwater for irrigation has reduced groundwater levels and increased carbon emissions. Estimates of C emissions from groundwater pumping for irrigation in Punjab indicate that over a period of 14 years (1998–2012), groundwater use has increased by 23%; groundwater levels have fallen by 5.47 m; energy requirements have increased by 67% resulting in increase in C emissions by 110%. Emissions rates have increased from 33 to 55 g m −3 of groundwater used, and 43.2 to 78 g‐C kg −1 of grain. Thus, groundwater management is not only important to ensure sustainability of the finite resource but also is vital to control environmental consequences of groundwater use for irrigation. Copyright © 2016 John Wiley & Sons, Ltd.