Life-cycle greenhouse gas assessment of Community Supported Agriculture in California's Central Valley

2017 ◽  
Vol 33 (5) ◽  
pp. 393-405 ◽  
Author(s):  
Libby O. Christensen ◽  
Ryan E. Galt ◽  
Alissa Kendall

AbstractMany consumers are trying to reduce their food's environmental impact by purchasing more locally sourced food. One choice for local food is Community Supported Agriculture (CSA), in which farmers provide a share of produce on a regular basis to pre-paying farm members. The number of CSAs in the USA has grown from two in the mid-1980s to perhaps as many as 12,617 according to the latest US census of agriculture (2014). We use a case study approach to investigate the greenhouse gas (GHG) emissions associated with five CSA operations in the Sacramento Valley of California. By understanding the GHG emissions of CSAs and the practices that might be improved, we hope to support innovative strategies to reduce GHG emissions in these agricultural production systems. Input, production and distribution data were collected from each farm and reported in CO2e emissions for 1 kg CSA produce at the pickup location. Results show large variation in total emissions, ranging from 1.72 to 6.69 kg CO2e kg−1 of produce with an average of 3.94 kg CO2e kg−1 produce. The largest source of emissions was electricity, contributing over 70% of total CO2e emissions on average. Based on our findings, despite the seemingly similarities between these operations in terms of production site, acreage, customers and production practices, there is still a large amount of variability with regard to total GHG. Thus we argue coming up with a standardized production function for diversified production and deriving GHGs or calculating average total emissions overlooks the heterogeneity of the system. Food systems can never be reduced to a simple binary of local is better and conventional is worse, or its inverse local is worse and conventional is better, because of the complexities of the production and distribution systems and their relationship to GHG emissions. Yet, we can say that localized production systems that are low in electricity use (or use renewable energy sources) and use efficiently-produced compost use have lower GHG emissions than those that do not.

Author(s):  
Anneli Lofstedt ◽  
Baukje de Roos ◽  
Paul G. Fernandes

Abstract Purpose To review the seafood dietary recommendations of European countries and compare them to national seafood supplies. Methods Current seafood dietary recommendations were collated from national health authorities across Europe. Food balance sheets were downloaded from the FAO, and appropriate conversion factors were applied to each seafood commodity. Average net per capita seafood supplies from 2007 to 2017 were derived from data on imports and production for food from both capture fisheries and aquaculture, accounting for exports. Results Both national dietary recommendations and seafood supplies varied considerably throughout Europe. At a national level, on a per capita basis, only 13 out of the 31 of European dietary recommendations for fish consumption were satisfied by national seafood supplies. Most of the countries with coastal access, as well as those with traditional fish-eating cultures, such as France and countries in Northern Europe, had adequate seafood supplies to meet their recommendations. The landlocked countries of Central and Eastern Europe did not have enough seafood supplies to satisfy their recommendations. Conclusions Our findings emphasise the need to not only consider consumer health outcomes when developing and advocating dietary recommendations, but also the sustainability of food production systems. As many foods are not necessarily locally sourced but traded as part of global production and distribution systems, it is important to consider greater consistency between national dietary recommendations to facilitate more sustainable marine food systems.


2020 ◽  
Author(s):  
Thomas D Alcock ◽  
David E Salt ◽  
Stephen J Ramsden

AbstractSunflower (Helianthus annuus L.) is the largest source of vegetable oil in Europe and the fourth largest globally. Intensive cultivation and post-harvest steps contribute to global food-systems’ greenhouse gas (GHG) emissions. However, variation between production systems and reporting disparity have resulted in discordance in previous emissions estimates. To assess systems-wide GHG implications of meeting increasing edible oil demand using sunflower, we performed a unified re-analysis of primary life cycle inventory data, representing 995 farms in 11 countries, from a saturating search of published literature. Total GHG emissions varied from 1.1 to 4.2 kg CO2-equivalent per kg oil across systems, 62% of which originated from cultivation. Major emissions sources included diesel- and fertiliser-use, with irrigation electricity contributing most to between-systems variation. Our harmonised, cross-study re-analysis not only enabled robust comparisons and identification of mitigation opportunities across sunflower oil production systems, but also lays the groundwork for comparisons between alternative oil crops.


2017 ◽  
Vol 6 (2) ◽  
pp. 66 ◽  
Author(s):  
Maria Storrle ◽  
Hans-Jorg Brauckmann ◽  
Gabriele Broll

This study investigates the amounts of greenhouse gas (GHG) emissions due to manure handling within different livestock production systems in Tyumen oblast of Western Siberia. Tyumen oblast occupies approx. 160 000 km² of Asian taiga and forest steppe. The amount of GHGs from manure was calculated as a function of the handling according to current IPCC guidelines for ecozones and livestock production systems. The entire Tyumen oblast has annual 7 400 t methane emissions and 440 t nitrous oxide emissions from manure. Three livestock production systems are prevalent in Tyumen oblast: Mega farms, small farms and peasant farms. The share of mega farms is 81 % (171 kt CO2 eq). Additionally, the slurry system in mega farms causes environmental pollution. GHG emissions and environmental pollution could be reduced by implementing solid manure systems or pasturing, by installing storage facilities for slurry outside the stables and through application of the manure as fertiliser at mega farms. In small farms solid manure systems and a small stocking density of livestock lead to smallest GHG emissions (1 %, 3 kt CO2 eq) from manure. In peasant farming 18 % (38 kt CO2 eq) of GHGs are emitted due to pasturing. 


2021 ◽  
Author(s):  
Elsbe von der Lancken ◽  
Victoria Nasser ◽  
Katharina Hey ◽  
Stefan Siebert ◽  
Ana Meijide

<p>The need to sustain global food demand while mitigating greenhouse gases (GHG) emissions is a challenge for agricultural production systems. Since the reduction of GHGs has never been a breeding target, it is still unclear to which extend different crop varieties will affect GHG emissions. The objective of this study was to evaluate the impact of N-fertilization and of the use of growth regulators applied to three historical and three modern varieties of winter wheat on the emissions of the three most important anthropogenic GHGs, i.e. carbon dioxide (CO<sub>2</sub>), methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O). Furthermore, we aimed at identifying which combination of cultivars and management practises could mitigate GHG emissions in agricultural systems without compromising the yield. GHG measurements were performed using the closed chamber method in a field experiment located in Göttingen (Germany) evaluating three historical and three modern winter wheat varieties, with or without growth regulators under two fertilization levels (120 and 240 kg nitrogen ha<sup>-1</sup>). GHG measurements were carried out for 2 weeks following the third nitrogen fertilizer application (where one third of the total nitrogen was applied), together with studies on the evolution of mineral nitrogen and dissolved organic carbon in the soil. Modern varieties showed significantly higher CO<sub>2</sub> emissions (i.e. soil and plant respiration; +23 %) than historical varieties. The soils were found to be a sink for CH<sub>4,</sub> but CH<sub>4</sub> fluxes were not affected by the different treatments. N<sub>2</sub>O emissions were not significantly influenced by the variety age or by the growth regulators, and emissions increased with increasing fertilization level. The global warming potential (GWP) for the modern varieties was 7284.0 ± 266.9 kg CO<sub>2-eq</sub> ha<sup>-1</sup>. Even though the GWP was lower for the historic varieties (5939.5 ± 238.2 kg CO<sub>2</sub>-<sub>eq</sub> ha<sup>-1</sup>), their greenhouse gas intensity (GHGI), which relates GHG and crop yield, was larger (1.5 ± 0.3 g CO<sub>2</sub>-<sub>eq</sub> g<sup>-1</sup> grain), compared to the GHGI of modern varieties (0.9 ± 0.0 g CO<sub>2</sub>-<sub>eq</sub> g<sup>-1</sup> grain), due to the much lower grain yield in the historic varieties. Our results suggest that in order to mitigate GHG emissions without compromising the grain yield, the best management practise is to use modern high yielding varieties with growth regulators and a fertilization scheme according to the demand of the crop.</p>


2018 ◽  
Vol 58 (6) ◽  
pp. 980 ◽  
Author(s):  
Richard Rawnsley ◽  
Robyn A. Dynes ◽  
Karen M. Christie ◽  
Matthew Tom Harrison ◽  
Natalie A. Doran-Browne ◽  
...  

Recognition is increasingly given to the need of improving agricultural production and efficiency to meet growing global food demand, while minimising environmental impacts. Livestock forms an important component of global food production and is a significant contributor to anthropogenic greenhouse-gas (GHG) emissions. As such, livestock production systems (LPS) are coming under increasing pressure to lower their emissions. In developed countries, LPS have been gradually reducing their emissions per unit of product (emissions intensity; EI) over time through improvements in production efficiency. However, the global challenge of reducing net emissions (NE) from livestock requires that the rate of decline in EI surpasses the productivity increases required to satisfy global food demand. Mechanistic and dynamic whole farm-system models can be used to estimate farm-gate GHG emissions and to quantify the likely changes in farm NE, EI, farm productivity and farm profitability as a result of applying various mitigation strategies. Such models are also used to understand the complex interactions at the farm-system level and to account for how component mitigation strategies perform within the complexity of these interactions, which is often overlooked when GHG mitigation research is performed only at the component level. The results of such analyses can be used in extension activities and to encourage adoption, increase awareness and in assisting policy makers. The present paper reviews how whole farm-system modelling has been used to assess GHG mitigation strategies, and the importance of understanding metrics and allocation approaches when assessing GHG emissions from LPS.


2021 ◽  
Vol 25 (1) ◽  
pp. 587-599
Author(s):  
Jānis Kramens ◽  
Edgars Vīgants ◽  
Ivars Liepiņš ◽  
Linards Vērnieks ◽  
Viktorija Terjanika

Abstract A number of intergovernmental agreements, the most important of which are the Paris Agreement (UN Framework Convention on Climate Change) and the European Green Deal, provide for resource efficiency and the reduction of greenhouse gas and particulate matter (PM2.5, PM10) emissions to 2030 (short-term program to reduce emissions by at least 55 %) and to achieve emissions-neutral production, transport and household activities by 2050. The European Union (EU) has taken the lead in developing and implementing climate change mitigation policies for both industrial and private residential homes in the world through a green course. As an EU country, Latvia has joined both the EU-level climate policy and developed its policy, regulatory documents and action plans for 2021–2030 (Latvia’s National Energy and Climate Plan for 2021–2030), climate policy, including a policy aimed at significantly reducing GHG emissions and increasing efficiency in the household sector. Achieving these climate policy goals requires both a change in human habits and more efficient technologies. This article discusses one of the technological solutions that can reduce both greenhouse gas emissions and the release of PM2.5 and PM10 from individual heating systems in private homes and small commercial facilities. Calculations of electrical energy production in mCHP mode of the system for household self-consumption based on experiments will be done. The technology involves the production of heat from biomass or other types of renewable energy sources while generating electricity for self-consumption. Conclusions of CHP mode on overall efficiency will be done.


Author(s):  
Celia Green ◽  
Andrew Joyce ◽  
Jonathan Hallett ◽  
Toni Hannelly ◽  
Gemma Carey

This chapter examines the link between dietary choices and greenhouse gas (GHG) emissions and possible interventions to reduce this impact. The connections between climate change, food systems and public health are explored. It is shown that there is variance in the impact of different food types on GHG emissions, with animal products having the greatest impact. The role of food system activities in the production of GHG emissions is also explored. Dietary choices and GHG emissions are examined using case studies from a variety of countries. Results show that reduced animal food production has increased potential to reduce GHG emissions compared to technological mitigation or increased productivity measures. Finally, a systems science approach is used to explore possible interventions aimed at reducing consumption of animal products.


2020 ◽  
Author(s):  
Markus Millinger ◽  
Philip Tafarte ◽  
Matthias Jordan ◽  
Alena Hahn ◽  
Kathleen Meisel ◽  
...  

<p>The increase of variable renewable energy sources (VRE), i.e. wind and solar power, may lead to a certain mismatch between power demand and supply. At the same time, in order to decarbonise the heat and transport sectors, power-based solutions are often seen as promising option, through so-called sector coupling. At times when VRE power supply exceeds demand, the surplus power could be used for producing liquid and gaseous electrofuels. The power is used for electrolysis, producing hydrogen, which can in turn be used either directly or combined with a carbon source to produce hydrocarbon fuels.</p><p>Here, we analyse the potential development of surplus power for the case of Germany, at an ambitious VRE expansion until 2050 and perform a cost analysis of electrofuels at different production levels using sorted residual load curves. These are then compared to biofuels and electric vehicles with the aid of an optimisation model, considering both cost- and greenhouse gas (GHG)-optimal options for the main transport sectors in Germany.</p><p>We find that, although hydrocarbon electrofuels are more expensive than their main renewable competitors, i.e. biofuels, they are most likely indispensable in addition for reaching climate targets in transport. However, the electrofuel potential is constrained by the availability of both surplus power and carbon. In fact, the surplus power potential is projected to remain limited even at currently ambitious VRE targets for Germany and carbon availability is lower in an increasingly renewable energy system unless direct air capture is deployed. In addition, as the power mix is likely to contain fossil fuels for decades to come, electrofuels based on power directly from the mix with associated conversion losses would cause higher GHG-emissions than the fossil transport fuel reference until a very high share of renewables in the power source is achieved. In contrast, electric vehicles are a more climate competitive option under the projected power mix with remaining fossil fuel fractions, due to a superior fuel economy and thereby lower costs and emissions.</p><p>As part of the assessment, we quantify the greenhouse gas abatement costs for different well-to-wheel pathways and provide an analysis and recommendations for a transition to sustainable transport.</p>


2016 ◽  
Vol 34 (2) ◽  
pp. 277-284
Author(s):  
Hernando Criollo E. ◽  
Amanda Silva P. ◽  
Hernando Delgado H.

This research focused on the greenhouse gas (GHG) emissions and potential sinks associated with conventional and sustainable fruit production systems in the Highlands region of Pasto, Nariño, Colombia. Based on the IPCC (2006) methodologies, the annual emission balance for a 6-year production cycle included agricultural sources and gasoline consumption related to the main agricultural activities and the potential for soil C accumulation and biomass C fixation in all of the studied systems. The multivariate analysis showed that positive GHG balance emissions would be achieved in all sustainable fruit production systems, as compared to conventional fruit production systems with greater impact on (SS1): Rubusglaucus Benth. associated with Acacia decurrens trees and live coverage of kikuyu Pen-nisetum clandestinum grass. According to the results of this study, (SS1) showed the beneficial total GHG balance emission accounting for -21,079 kg of atmospheric CO2eq ha-1 yr-1 divided into -4,587 kg CO2eq ha-1 yr-1 and -17,102 kg CO2eq ha-1 yr-1 due an annual soil and biomass C sequestration potential that could help offset its emissions (610 kg CO2eq ha-1 yr-1).


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