10 Things You Need To Know Before Making Your Own LCA
1) Do not rely solely on any one online database. Google Scholar, Web of Knowledge, Engineering Village…..
2) Critical information is often found in non-refereed publications, consultant reports, NGOs, etc. While it is worth carefully evaluated these sources for bias, they can otherwise provide estimates for hard-to-find figures.
3) Published LCAs are a helpful tool if you can find one, but are not always reliable. They often list the impacts without providing the inventory of inputs and outputs. Furthermore, they also make assumptions, use short-cuts, and ignore processes, and it is important to read the entire paper (not just glance at the tables) to understand where this has occured.
4) That being said, you will likely need to extrapolate some figures yourself. Many of our case studies are in areas where there is not an abundance of scientific literature (e.g. Haiti, Iraq), or where projects are too new to have amassed a wealth of information (e.g. Three Gorges). In this case, extrapolating information from similar countries is acceptable, provided you record where and why this has occured.
5) While searching for articles, use a variety of search terms. Substitute agriculture for agronomy, LCA for impact assessment or input-output analysis, etc.
6) When you’ve finished, conduct a sensitivity analysis using some realistic alternative scenarios.
7) For agricultural LCAs, it can be easier to start with the functional unit of a hectare, and convert this to tonnage once you’ve finished. Most agricultural data will be presented as units x/ha, so this will save time.
8) Outputs are generally dependent upon the inputs. It is important to consider this when choosing estimates. For instance, it wouldn’t be accurate to use a nitrous oxide emission figure from a study without accounting for the nitrogen fertilizer used. You will have to find a way to account for this when using estimates from different papers.
9) 75% of the time you spend on your LCA will likely be reading papers, so read carefully.
10) Don’t let technical papers intimidate you. Use an excel spreadsheet to change complicated processes and figures into more transpicuous equations.