First, it is often cited that LCA results should not be compared (Desjardins et al., 2012; Foster et al., 2006; McAuliffe et al., 2016; Röös et al., 2013) due to variation in methodology choices, functional units, as well as temporal and regional differences2. Second, no single comprehensive review was identified that adequately covers the breadth of fresh foods available to consumers and caterers. As Helle et al. (2013, p.12643) state ‘data availability and quality remain primary obstacles in diet-level environmental impact assessment’, while Pulkkinen et al. (2015) calls for the creation of a database that communicates data quality, uncertainty and variability to reliably differentiate between the GWP of food types. Previous studies have compiled LCA data to compare different foods (e.g. Audsley et al., 2009; Berners-Lee et al., 2012; Bradbear and Friel, 2011; de Vries and de Boer, 2010; Foster et al., 2006; Nijdam et al., 2012; Sonesson et al., 2010; Roy et al., 2009). While these are useful attempts, the identified studies are inadequate in the coverage of fresh foods available. Environmental Product Declarations (EPDs) attempt to inform consumers of the environmental impacts (carbon, water and ecological footprint) of specific foods, however they also fall short in breadth of items covered at present. The most comprehensive attempt at carbon footprint labelling was performed by Tesco (2012), however failed to label key categories such as fresh fish, pork, lamb or beef before finishing in 2012 due to the scale of the labelling scheme and a lack of participation from other retailers (Head et al., 2013). Third, studies that do compare results may often present singular figures. Peters et al. (2010) and Röös et al. (2011) argue that a range of impacts should be reported from LCA’s to better represent the variety of environmental impacts, as opposed to a singular figure. Finally, there is a lack of synthesised open access LCA data in the public domain available to consumers to inform decision-making.
It’s exceptionally funny to me that you didn’t link to the study you’re quoting, because if you did, people would find out that you’re quoting a systematic review & meta-analysis of 369 LCA studies in the same vein as Poore & Nemecek 2018 did with 1530 LCA studies.
The ENTIRE POINT of the study you just quoted was that “there is a lack of synthesised open access LCA data in the public domain available to consumers to inform decision-making. Therefore this paper presents a systematic literature review and meta-analysis of food LCA studies in the last 15 years to assess the GWP of fresh food.” Thus, they appropriately synthesized the data using a meta-analysis. You’ve literally just disproven your own point. I hope you don’t actually believe that people reading this comment will fall for this.
I’m not trying to taunt you, rather I’m being completely serious: did you read the study you just linked beyond what you quoted?
they were honest enough to acknowledge that these studies varied so widely in methodology that combining them would be bad science, but went on to do it anyway. poore-nemecek doesn’t even acknowledge their faux pas.
That’s your characterization here? That’s the level of bad faith you’re acting on? That they spent an entire paragraph right upfront citing other papers talking about potential pitfalls for the express purpose of intentionally implicating themselves before doing it? Are you high? Or just deeply scientifically illiterate?
The entire point of that paragraph is to show that there are pitfalls if taking a naïve approach, but that an appropriately thought-out meta-analysis can meaningfully synthesize LCAs into one set of data, which they go on to explain in their ‘Methodology’.
