Anja Hansen

To achieve national and global air quality and climate change objectives, the agricultural sector increasingly requires dependable decision support tools for gaseous emissions at the farm level. We evaluated thirteen greenhouse gas (GHG)-based decision support systems (DSS), considering criteria such as not only the accessibility, user-friendliness, stakeholder involvement, sustainability methodology, and modeling aspects, but also the input parameters and outputs provided, all crucial for decision making. While most DSSs provide information for facilitating their use, only four are suitable for inexperienced users, and stakeholder participation in DSS development is infrequent. The dominant methodology for farm-level GHG estimation is IPCC 2006, with quantitative models primarily used for indicators’ assessment. Scenario and contribution analyses are the prevailing decision support approaches. Soil, crop, and fertilizer types are the most implemented non-livestock-related inputs, while climate- and feed-related costs are the least required. All DSSs assess farm-level mitigation measures, but less than half offer sustainability consultation. These tools promote environmental sustainability by evaluating mitigation strategies, disseminating farm sustainability information, and guiding sustainable farm management. Yet, challenges such as disparate estimation methods, result variations, comparison difficulties, usability concerns, steep learning curves, the lack of automation, the necessity for multiple tools, the limited integration of the results, and changing regulations hinder their wider adoption.

The authors wish to make the following corrections to this paper [1]:

Carbon (C) is a central element in organic compounds and is an indispensable resource for life. It is also an essential production factor in bio-based economies, where biomass serves many purposes, including energy generation and material production. Biomass conversion is a common case of transformation between different carbon-containing compounds. At each transformation step, C might be lost. To optimize the C use, the C flows from raw materials to end products must be understood. The estimation of how much of the initial C in the feedstock remains in consumable products and delivers services provides an indication of the C use efficiency. We define this concept as Carbon Utilization Degree (CUDe) and apply it to two biomass uses: biogas production and hemp insulation. CUDe increases when conversion processes are optimized, i.e., residues are harnessed and/or losses are minimized. We propose CUDe as a complementary approach for policy design to assess C as an asset for bio-based production. This may lead to a paradigm shift to see C as a resource that requires sustainable exploitation. It could complement the existing methods that focus solely on the climate impact of carbon.

Bioresources are used in different production systems as materials as well as energy carriers. The same is true for fossil fuel resources. This study explored whether preferential resource usages exist, using a building insulation system as an example, with regard to the following sustainability criteria: climate impact, land, and fossil fuel demand. We considered the complete life cycle in a life cycle assessment-based approach. The criteria were compared for two strategies: one used natural fibers as material and generated production energies from fossil fuels; the other generated production energies from bioenergy carriers and transformed fossil resources into the insulation material. Both strategies finally yielded the same insulation effect. Hence, the energy demand for heating the building was ignored. None of the strategies operated best in all three criteria: While cropland demand was lower in the bioenergy than in the biomaterial system, its fossil fuel demand was higher. Net contribution to climate change was in the same range for both strategies if we considered no indirect changes in land use. Provided that effective recycling concepts for fossil-derived insulations are in place, using bioresources for energy generation was identified as a promising way to mitigate climate change along with efficient resource use.

This study presents a cradle‐to‐gate assessment of the energy balances and greenhouse gas (GHG) emissions of Indonesian palm oil biodiesel production, including the stages of land‐use change (LUC), agricultural phase, transportation, milling, biodiesel processing, and comparing the results from different farming systems, including company plantations and smallholder plantations (either out growers or independent growers) in different locations in Kalimantan and Sumatra of Indonesia. The findings demonstrate that there are considerable differences between the farming systems and the locations in net energy yields (43.6–49.2 GJ t⁻¹ biodiesel yr⁻¹) as well as GHG emissions (1969.6–5626.4 kg CO_2eq t⁻¹ biodiesel yr⁻¹). The output to input ratios are positive in all cases. The largest GHG emissions result from LUC effects, followed by the transesterification, fertilizer production, agricultural production processes, milling, and transportation. Ecosystem carbon payback times range from 11 to 42 years.