Multiple Cropping System Expansion: Increasing Agricultural Greenhouse Gas Emissions in the North China Plain and Neighboring Regions

Xueyan Zhang

doi:10.3390/su11143941

Abstract

The increase of agricultural greenhouse gas (GHG) emissions has become a significant issue for China, affecting the achievement of its Nationally Determined Contributions under the Paris Agreement. Expansion of the large-scale multiple cropping system as a consequence of climate warming could be a major driving force of this increase. In this study, life cycle assessment was employed to identify agricultural GHG emissions due to the expansion of the multiple cropping system in the North China Plain and neighboring regions. We found that agricultural greenhouse gas emissions have increased from 41.34 to 120.87 Tg CO2-eq/yr over the past 30 years, and the expansion of the multiple cropping system has contributed to 13.89% of this increment. Furthermore, the increases in straw handling and agricultural inputs which are related to multiple cropping systems have also played an important role. Results of our study demonstrate that the expansion of the multiple cropping system contributes considerably to increases in agricultural GHG emissions in the North China Plain and neighboring regions. Therefore, it can be concluded that the sustained northward expansion of the multiple cropping system will further elevate agricultural GHG emissions in China, and this should be considered while formulating policies to reduce GHG emissions from agriculture.

Highlights

China is the largest emitter of greenhouse gases (GHGs) and has promised to achieve the peak of carbon dioxide emissions around 2030 in its Nationally Determined Contributions (NDCs) under the Paris Agreement
In view of the crucial role played by multiple cropping systems (MCSs) in China’s food security system, it is expected that the sustained expansion of MCSs will further elevate the emissions of agricultural GHGs upon climate change
This study revealed that straw handling and agricultural inputs are important sources of agricultural GHG emissions

Summary

Introduction

China is the largest emitter of greenhouse gases (GHGs) and has promised to achieve the peak of carbon dioxide emissions around 2030 in its Nationally Determined Contributions (NDCs) under the Paris Agreement. GHG emissions from agriculture increased substantially from 0.61 to 0.92 Pg CO2-equivalence (CO2-eq) from 1994 to 2012 [3,4]. Tian et al reported that agricultural GHG emissions show a clear upward trend with an average annual growth rate of 3.10% in China from 1995 to 2010 [5]. This increase in agricultural GHG emissions has become an important sustainability issue to ensure that China meets its Nationally Determined Contributions under the Paris Agreement [6,7]. Agriculture is a non-point source of GHG emissions, which is closely related to the sown area and multiple cropping systems (MCSs) [9]

Objectives

Results

Conclusion