Outline of the video

• 0:05 What is conversion? Whenever you do a material flow analysis or a circularity assessment of a city or of a sector, what you want to do is to measure stuff in tonnes or in kilogrammes or in mass terms. Our goal here is to be able to compare flows one with another. So if you have flows in different units, then it's not possible.
• 0:32 main challenge you're gonna find data in different units.
  • Sometimes you're gonna find animals in terms of heads, how many heads you have in your forest or in a particular city
  • you might be able to find how much road network or rail network you have but not in kilograms, but instead in terms of length.
  • some imports and exports are also reported in monetary terms in Euros and dollars.
  • sometimes you know waste flows or waste water flows or water flows are measured in cubic metres or in litres.
  
  
• 1:19 How to solve the problem We try to find conversion factors. We try to convert from whatever other unit is to a material unit. So a mass unit in terms of kilograms, tons kilotons.
• 1:39 two examples
  • one example in the case of Bodø, Norway, where what we had was the number of cubic metres of roundwood that was harvested every year. So we went about and looked for conversion factors.
  • 2:29 So sometimes for instance, the European commission provides these and this is for instance, in the case of how much animals weigh. So over here there is a table that kind of gives you a minimum and maximum range of mass per type of animal.
  
  
• 3:33 How to get to tonnes Well, you just multiply the two in order to get to tonnes. If I have the number of bulls that exist in my city or, or that are killed for, to enter within the economy, I would just multiply this by the mean between the two, the mean between the min and the max or have a range. So if it's 100 times 100 30 kg, it would be 1.3 tons.