Getting the data right

April 22, 2021 by admin

This is the title of a large new 4-year project to create a globally unique virtual lab and open database tool for quantitative assessment of the climate effects of decision alternatives, popularly speaking ‘a climate footprint generator’, and a mechanism to ensure its continuous maintenance. The project builds on our experiences with two of the most used LCA databases: the consequential version of the ecoinvent database and the hybrid version of EXIOBASE.

A total of nine full-time persons and 5 Ph.D’s will be working on this project in the next 4 years. We are currently assessing applicants for these jobs.
Read more at the project website.

Consequential versus normative food LCAs

February 15, 2021 by Bo Weidema

On February 1th, our client CONCITO – Denmark’s Green Think Tank published the results of the project ‘LCA of 500 food items’ and created quite a wake in the press and on social media.

The database, which was published under the somewhat pretentious name “The Big Climate Database”, presents climate footprints of 500 selected foodstuffs in an accessible and transparent tool intended as a basis for climate footprint calculation of meals and purchases, as well as for information and teaching.

The database was received with excitement by the Danish public. The day after the publication, the Danish Television published a quiz where consumers could test their knowledge and showed how to prepare mussels, one of the products with lowest climate footprint in the database.

However, several producers’ associations were critical and even allegations of ‘deception’ were put forward. Much to our satisfaction, Michael Minter from CONCITO calmly replied to these criticisms in a blog post and in such an eloquent way that I want to share some of his replies (in my own translation):

Scientists from two Danish universities that have been advising the Danish authorities based on the normative (attributional) LCA approach lament that it is not possible to compare their data with those of the new consequential climate database and fear that consumers and politicians might be confused.

Figure 1 – CO2 equivalent of tenderloin

Especially the high climate footprint of tenderloin (compared to other meat cuts) in the database has been the subject of much debate, since previous reports have only shown the climate footprint for average beef – and this is the highest number the Danish public has yet seen on a beef product.

CONCITO points out that the purpose of the climate database is to compare different food choices, potentially leading to changes in the consumption towards products with a lower climate impact. Therefore, far from being a mistake, the consequential approach is a deliberate choice of method.

In the blog post, CONCITO explains how it is possible with a difference between what consumers influence by changing the demand for a product, and the emissions from the products that you physically use – something can indeed be hard to comprehend. In my translation below:

The consequential approach takes into account that a change in demand for a product is not necessarily met by just any manufacturer on the market. For example, the dairy system is very inelastic when it comes to responding to changes in demand for beef. In other words, you do not increase milk production, and the subsequent output of cows and calves for slaughter, when the consumption of beef increases.

The normative approach used by Aarhus University includes all animals that are on the Danish market for beef, and here dairy cows and their offspring are included as a normative fixed percentage of the milk system.

With the consequential approach in the climate database, the climate footprint from beef will be significantly higher than in the normative LCA. This is partly due to the fact that pure beef cattle herds have a major climate impact. Another significant factor is that the consequential approach also includes the climate impact from indirect land use and deforestation to either grazing or fodder production, which is often omitted in the normative approach’.

The use of the price of the different meat cuts to calculate their relative climate footprints has been another point of critique from meat producers and some consumers. But here is the clue:

how much a slaughterhouse increases production when the demand for a given cut changes, can be identified by using the price of the product being sold. The slaughterhouses determine the price of various cuts so that they on the one hand ensure as much income as possible, and on the other hand ensure that all their meat is sold. Therefore, it is the price of the meat sold, and not the quantity in kilograms, that determines how much extra production from the slaughterhouse is induced through a change in the demand for a given cut’.

CONCITO goes on to give this illustrative example of how the database can be used:

The average climate footprint of beef from the slaughterhouse is 50.2 kg CO2e per kg, while the distribution of the climate footprint on the various cuts is between 31 kg CO2e per kg minced beef and 152 kg CO2e per kg beef tenderloin. If the choice is between, for example, 1 kg of minced beef and 1 kg of beef tenderloin, the best climate choice will be 1 kg of minced beef. If the choice is between DKK 100 for minced beef and DKK 100 for beef tenderloin, there will be no difference in the climate footprint.’

The debate on wild fish and farmed fish illustrates another core aspect of the consequential approach, namely what happens when a market is constrained.

The producer’s association for the Danish fisheries considers the climate database ‘flawed’ because it calculates the climate impact from farmed fish and not from the wild fish they actually catch, which may have a lower impact.

But CONCITO again reminds us that the purpose of the climate database is to provide information on the climate consequences of a change in demand. For fish, an increase in demand will ultimately affect fish farming, no matter if your fish is caught in the sea or comes from aquaculture. Here is the reasoning from CONCITO:

The results for fish are based on internationally recognized studies that show that the amount of wild-caught fish does not change. There are lots of fish in the oceans, but the market is controlled by quotas and we cannot just catch more than we do today.

Wild-caught seafood is generally a globally limited resource that cannot be increased, since the carrying capacity of the ecosystems is fully utilised in virtually all parts of the world. However, this does not apply to marine molluscs such as mussels, oysters and squid, which are found in abundant quantities.

Good fisheries management can help to increase fish stocks. However, considering that aquaculture today accounts for almost half of the world’s fish production, it is difficult to see how changes in local fisheries management in the EU can make a significant difference in the global fish market.’

Several dairy and meat producers’ organisations have criticised the climate database, primarily from the point of view that it is misleading to state the climate footprint per kg of food instead of the content of nutrients. They argue that food is chosen for nutritional value, calories and nutrition – so a kilogram of cucumber and a kilogram of meat is not comparable.

CONCITO points out that the nutritional content of the food is shown in the description for each of the products in the database. However, the climate footprint per kg of food is simply the most relevant and practical measure for food choices as part of complex dishes:

‘In addition to taste and enjoyment, we eat to get full and get the necessary nutrients – not to get as many calories, proteins, etc as possible. When we need to optimize the diet in relation to climate and health, the nutritional content is not the relevant measure. For example, no one buys according to calories or proteins, and most Danes today consume too many nutrients.

Besides that, recipes and shopping lists are normally described and accounted for by the weight of the different ingredients and products – not the amount of calories, protein, etc. The typical consumer goes out to buy 1 kg of potatoes – not 20 grams of potato protein.

The climate database has as its sole purpose to put focus on the climate impact of what you put in your shopping basket or meal, not to compose a nutritionally optimal purchase or meal. For that, it is preferable to orient oneself in the Danish official dietary advice.

With the combination of the climate database for the 500 foods and this brand new official dietary advice – where good things are said about living both climate friendly and healthy on a whole-grain and mainly plant based diet – the Danes have free access to the – also in international context – most comprehensive, detailed, consistent and transparent information on how to make climate friendly food choices.

That said – we still miss to see political action in Denmark. Because, honestly, climate problems cannot be solved by consumer choices alone.

11 SDG pathways ready

August 11, 2020 by Bo Weidema

Just finished the 11th out of the 17 SDG pathways for quantitative SDG impact assessment. They are now ready for inspection in our SDG club and for the business partners of the project ”Linking the UN Sustainable Development Goals to life cycle impact pathway frameworks”. The remaining 6 SDGs will be covered within the next few months. We have focused on describing in detail the business ”pressure” indicators (in LCA speak: Life Cycle Inventory indicators), so that the business partners can start data collection for the foreground processes of their pilot case studies.

Impact pathways for issues related to “Education” (mainly SDG 4). This is one of the 11 impact pathway diagrams that are now ready. See more examples in the public report.

Even if you are not an SDG club member or business partner for this project, you can have a look at the first results from the project, which have just been made public in the report “LCA-based assessment of the Sustainable Development Goals”. The report describes two different applications: A qualitative life cycle SDG screening building on existing LCA results, and a quantitative life cycle SDG assessment (LCSA) that goes beyond existing LCA indicators, quantifying the impact pathways, and making the contributions to the SDGs comparable by tracing all impacts to a single-score: the ultimate endpoint of sustainable wellbeing. This allows organizations to calculate how much their product contributes to each SDG, target, and indicator, as well as to overall sustainable wellbeing.

For me, the next step will be to finalise a rough quantification of all the 17 impact pathways, so that the data collection and the further detailing can focus on the impact pathways that have the largest importance for overall sustainability.

For the business partners, the next step will be the foreground data collection for their case studies, so that we can start testing the screening and LCSA methods in practice. If your organisation wishes to participate in this first testing round, we still have room for more business partners. Contact me at .

Economy in circles

July 29, 2020 by Bo Weidema

Circular Economy (CE) has become a hot topic. A new ISO Technical Committee, ISO TC323, will now seek to standardise the terms and measurement indicators for CE, and its four Working Groups have started drafting text for new standards. From 2.-0 LCA consultants, we are taking active part in this international standardisation work, as we have previously done for Life Cycle Assessment (LCA).

One of the topics that are now debated is the relationship between LCA and CE. This month, the UNEP Life Cycle Initiative published a position paper on this topic.

The position paper reminds us that Circular Economy (CE) originally was a concept coined by Pearce & Turner (1990) as an economy where wastes are recycled into resources, either through a technological feedback mechanism or through a natural ecosystem feedback mechanism, so that the stock of resources is constant or increasing over time. In other words, a circular economy is a sustainable economy. However, in the current interpretations and implementations of CE strategies, a narrower view is sometimes taken, focussing on specific physical resources, assuming that these resources are the most valuable area of protection, ignoring other resources or impacts. 

LCA has the intention to avoid burden shifting between different life cycle stages or between different resources or impacts. It can therefore be argued that LCA applied to CE strategies should be able to prevent CE strategies from overlooking potential upstream and downstream impacts, and looking beyond specific resources to a more holistic assessment of the biophysical, social and economic effects of a decision.

However, also LCA is often applied with a too narrow perspective, and the position paper highlights a number of preconditions for LCA to play the desired role:

  • Consistent accounting for changes in stocks of resources respecting mass balance principles.
  • Consistent modelling of open recycling loops.
  • The inclusion of all relevant resources and impacts, i.e. a full economy-wide Life Cycle Sustainability Assessment perspective.
  • Transparency of assumptions, reliability of data, and critical interpretation of results and trade-offs between a globally agreed numbers of impact categories, e.g. through valuation, as suggested in ISO 14008.

For both LCA and CE, it may be more economical to circle back to the original intentions and definitions, than to spiral down blind alleys of simplified interpretations and applications.


Pearce D W, Turner P K. (1990). The economics of natural resources and the environment. Hemel Hempstead: Harvester Wheatsheaf London 378 pp.

Claudia Peña C, Civit B, Gallego-Schmid A , Druckman A, Caldeira- Pires A , Weidema B, Mieras E , Wang F , Fava J , Milà i Canals L , Cordella M, Arbuckle P, Valdivia S, Fallaha S , Motta W (2020). Using Life Cycle Assessment to achieve a circular economy. Position Paper of the Life Cycle Initiative, July