Energy Consumption, Carbon Emissions and Global Warming Potential of Wolfberry Production in Jingtai Oasis, Gansu Province, China

During the last decade, China's agro-food production has increased rapidly and been accompanied by the challenge of increasing greenhouse gas (GHG) emissions and other environmental pollutants from fertilizers, pesticides, and intensive energy use. Understanding the energy use and environmental impacts of crop production will help identify environmentally damaging hotspots of agro-production, allowing environmental impacts to be assessed and crop management strategies optimized. Conventional farming has been widely employed in wolfberry (Lycium barbarum) cultivation in China, which is an important cash tree crop not only for the rural economy but also from an ecological standpoint. Energy use and global warming potential (GWP) were investigated in a wolfberry production system in the Yellow River irrigated Jingtai region of Gansu. In total, 52 household farms were randomly selected to conduct the investigation using questionnaires. Total energy input and output were 321,800.73 and 166,888.80 MJ ha−1, respectively, in the production system. The highest share of energy inputs was found to be electricity consumption for lifting irrigation water, accounting for 68.52%, followed by chemical fertilizer application (11.37%). Energy use efficiency was 0.52 when considering both fruit and pruned wood. Nonrenewable energy use (88.52%) was far larger than the renewable energy input. The share of GWP of different inputs were 64.52% electricity, 27.72% nitrogen (N) fertilizer, 5.07% phosphate, 2.32% diesel, and 0.37% potassium, respectively. The highest share was related to electricity consumption for irrigation, followed by N fertilizer use. Total GWP in the wolfberry planting system was 26,018.64 kg CO2 eq ha−1 and the share of CO2, N2O, and CH4 were 99.47%, 0.48%, and negligible respectively with CO2 being dominant. Pathways for reducing energy use and GHG emission mitigation include: conversion to low carbon farming to establish a sustainable and cleaner production system with options of raising water use efficiency by adopting a seasonal gradient water pricing system and advanced irrigation techniques; reducing synthetic fertilizer use; and policy support: smallholder farmland transfer (concentration) for scale production, credit (small- and low-interest credit) and tax breaks

Prospective life cycle assessment to avoid unintended consequences of net-zero solutions and its challenges

Climate change has led to specific carbon reduction targets including net-zero ones that are set to help in mitigating climate change by governments and organizations. This is not only to mitigate but also to meet the growing demands of the global population, while ensuring practical progress and implementation. In line with those targets, alternative low-carbon energy technologies as well as those that capture carbon from the atmosphere are being hailed as practical solutions. For example, the UK government has set the ambitious plan of reaching net zero by 2050 which requires renewable energy, nuclear, hydrogen and other low carbon fuels to be accelerated significantly, while increasing the share of carbon capture and storage (Rt Hon Chris Skidmore, 2022). These require innovation beyond existing technologies, i.e. developing emerging technologies. Although there is an optimistic view on the use of emerging technologies- as they may reduce energy use and subsequently CO2 emissions across different sectors-, such technologies require different materials than established technologies, which can introduce different types of emissions up and down the supply chain. Such burdens should be carefully studied from raw material requirement to the life cycle environmental impacts in order to avoid unintended consequences of the technologies in the future (Melin et al., 2021). Therefore, from the early stage of technology development prospective life cycle assessment (pLCA) should be employed to assess environmental impacts of emerging technologies (Bergerson et al., 2020). However, since the knowledge and information on the emerging technologies are limited and scattered, major challenges exist when performing pLCA, e.g. consistency in modelling foreground systems, data availability, uncertainty (Thonemann et al., 2020; van der Giesen et al., 2020). Here, we demonstrate some additional challenges by exploring emerging technologies for organizations using an example of a defence setting. The focus of this study is not on the war-related operations, but rather looking into the decarbonizing the Defence estates and infrastructure systems -that are used by the military- using some emerging technologies such as Hydrogen, Carbon Capture, Geothermal, Electric Vehicles, and Solar Photovoltaics. Most of the literature studies on pLCA focus on a single emerging technology development and its plausible sustainability impacts in the future. However, for government and organizations to achieve net zero targets, they usually need to implement array of emerging low-carbon energy technologies, some of which need to be employed in parallel e.g. emerging low-carbon energy generation and energy storage systems. This adds further complications and challenges to the pLCA as economics, environment and variability related issues. Firstly, different emerging technologies have different temporal horizons in reaching the commercial maturity and respected market and technology readiness level. Second, such assessments are complicated as finding the most optimal combination of different emerging technologies needs balancing pros and cons of different technologies in terms of different sustainability impacts which makes the problem a kind of multi-criteria problem that involves large number of variables (Torkayesh et al., 2022). Third, large deployment of emerging technologies would also imply some consequences on the marginal markets and that needs further considerations. Therefore, it is of great importance to assess emerging technologies on wider economic scales and consider potential market share of them. Finally, there are some technology and market interventions that also needs to be considered. All these challenges need proper remedies and further research when performing pLCA

Energy life-cycle assessment and CO₂ emissions analysis of soybean-based biodiesel: A case study

In this study the energy consumption and CO₂ emissions of biodiesel production from soybean in Golestan province of Iran were studied. For this purpose, the life-cycle process of biodiesel was considered as five stages of agricultural soybean production, soybean transportation, soybean crushing, biodiesel conversion, and its transportation. The results indicated that the total fossil energy consumption with coproduct allocation was 8617.7 MJ ha⁻¹ and the renewable energy output content (biodiesel as the final outcome) was estimated as 16,991.4 MJ ha⁻¹. The net energy gain (NEG) and the fossil energy ratio (FER) were calculated as 8373.7 MJ ha⁻¹ and 1.97, respectively, which show soybean is a suitable energy crop for biodiesel production. Agricultural soybean production stage ranked the first in energy consumption among the five main stages where it consumed 50.56% of total fossil energy consumption in the biodiesel life-cycle process. The greenhouse gas (GHG) emissions data analysis revealed that the total GHG emission was 1710.3 kg CO₂eq ha⁻¹ which biodiesel production life-cycle was only account for 311.96 kg CO₂eq ha⁻¹ if the mass allocation is considered. Overall, biodiesel production from soybean in Iran can be considered as a way to increase energy security in the near future. Also, soybean cultivation must be considered along with other common oilseeds cultivation in order to prevent food competition between biodiesel feedstocks and food production in Iran