Den 2019-03-13 kl. 17.07 skrev Massimo Pizzol:

Thanks.

 

Am I right that your comment is similar what you have replied already here on GDP?
My impression is that like in the GDP discussion you are proposing a breakdown of each modelling step by creating an activity object for each model variable (e.g. along an impact chain). Since, however, there might be a databases/ file somewhere on the web where a list of characterisation factors (like there are GDP data per country online), this dataset on the web could be linked to our flows directly and used for e.g. for validation the results obtained from the query mentioned above, or even for calculations without using the model breakdown.

Well, you can aggregate any number of activities (and thus also steps in an impact pathway) and thus obtain the desired characterisation factors (for non-LCA people: A characterisation factor is an output flow from a characterisation activity given in relation to the input of the determining flow to be characterised). And as such you can also store such aggregated activity data obtained as "raw" data, e.g. for comparison to the aggregated result of a specific more detailed modelling.

However, I don’t understand why in the first example you want to “follow the methane through some activities” and in the second one you want to use directly “weighting factors”. Seems inconsistent to me.

It stems from the fact that you asked about two different things: 1) carbon dioxide equivalents, which is a generic concept, 2) Global Warming Potentials, which are specific weighting factors for GreenHouseGases under a specific normative paradigm.

Best regards

Bo   

From: <hackathon2019@bonsai.groups.io> on behalf of "Bo Weidema via Groups.Io" <bo.weidema@...>
Reply-To: "hackathon2019@bonsai.groups.io" <hackathon2019@bonsai.groups.io>
Date: Wednesday, 13 March 2019 at 16.51
To: "hackathon2019@bonsai.groups.io" <hackathon2019@bonsai.groups.io>
Subject: Re: [hackathon2019] Competency Questions #ontology #rdf

 

Den 2019-03-13 kl. 16.28 skrev Massimo Pizzol:

Everything looks fine to me, I just miss some questions about impacts (and I realize that I am not sure if characterisation factors are included in our schema as properties or how …?). Examples:

 

(MP_Q1) What is the direct output flow of flow-object F from activity A measured by flow-property P in location L in the time period T under macro-economic scenario S?  

(example: What is the direct output of carbon dioxide from steel production measured in carbon dioxide equivalents in Germany in year 2020 under the Business-as-Usual scenario?) à Is this just another instance of type BW_Q1?

What flows out of the steel production is carbon dioxide. 1 kg of carbon dioxide = 1 kg of carbon dioxide equivalents, so I assume what you are thinking of is rather if the output was of, say, methane, which can also be expressed in carbon dioxide equivalents under a specific macro-economic scenario, and depending on where in the impact pathway you define the equivalence. So the most consistent way of dealing with this is to follow the methane through the following ecosystem activities "atmospheric energy balance" and "temperature increase" as a result of the additional input of methane. These processes will have outputs expressed in radiative forcing and temperature change, which can of course be compared to the radiative forcing and temperature change from a kg of carbon dioxide, so that you obtain the impacts of methane in carbon dioxide equivalents at the point in the impact pathway that you are interested in.

(MP_Q2) What is the additional output flow of flow-object F from activity A measured by flow-property P in location M in the time period T resulting from a demand of flow-object G in location M in the time period U, all under macro-economic scenario S?

(example: What is the additional global warming potential from steel production measured in carbon dioxide equivalents in year 2020 resulting from a demand of 100 square meter of office building in Spain in year 2019 under the Business-as-Usual scenario?) à Is this just another instance of type BW_Q6?

The global warming potential (given a specified time horizon) is a weighting factor applied to each greenhouse gas. This is most easily included in a separate weighting step. This could be done by adding the weighting as an activity, but I would suggest to use the E matrix suggested in http://lca-net.com/p/2865 for this purpose.

Best regards

Bo

 

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