Energy Needs and Greenhouse Gas Emissions in Agriculture

Introduction

While one of the main contributors, agriculture is also majorly affected by the climate crisis, which is why approaches for adaptation and mitigation are urgently necessary. Addressing emissions and global warming potential in agricultural activities is fundamental in order to reduce its impact. While creating new opportunities for food security, seeking clean energy solutions can also help combat climate change. Detecting the gaps for innovative opportunities requires first a thorough knowledge of the fundamentals of energy flows and greenhouse gas emissions (GHG) in agriculture.

GHG Emissions in Agriculture

GHG emissions from AFOLU activities have increased by almost 100 percent in the last 50 years, accounting for 23% of the total net GHG emissions between the years 2007-2016. However, if emissions associated with pre-and post-production activities in the global food system are included, the emissions are estimated to reach up to 37 percent of global anthropogenic GHG emissions. CO² accounts for 13 percent, methane (CH⁴) for 44 percent, and nitrous oxide (N²O) for 82 percent. The main emitters are livestock-related enteric fermentation (40 percent), manure left on pasture (16 percent), synthetic fertilizers (13 percent), paddy rice cultivation (10 percent), manure management (7 percent) and the burning of savannahs (5 percent). Read more…

Energy within Production and Processing

About 30 percent of global energy is consumed in the agriculture, forestry and land use (AFOLU) sector (2011). Energy is necessary at every level of the food value chain including the production of agricultural inputs, agricultural production in the field, food processing, transportation, marketing and consumption.

While all steps within the agricultural value chain require energy inputs of different kinds, primary production and food processing (including transport) cause the highest amount of emissions (20 and 40 percent, respectively). Primary production consumes energy indirectly by using fertilizers and pesticides, as their manufacturing is quite energy intensive. Further, diesel fuel needed for machinery (tillage), the operation of irrigation systems and fishing vessels cause considerable quantities of GHGs, on average 705 million tonnes CO2 eq. Within processing, most energy is consumed through washing, cleaning, cooking, cooling, extraction, pureeing, brewing, baking, pasteurizing, boiling, drying, dehydration and further processing steps for dairy products, meat, fish, fruits, vegetables, edible oil etc. These processes account for about 50 percent of electrical energy consumption within the agriculture sector. Read more…