Measuring GHG emissions from transport

Emissions from sea, land and air transport make a large but often poorly accounted share of the GHG and air pollutant footprints of consumption. PRINCE case studies explored two very different approaches to building consumption-based macroindicators for transport emissions along a country’s international supply chains.

Using MRIO to estimate GHG emissions from transport

The first approach used MRIO modelling, similar to other PRINCE indicators. Based on EXIOBASE data, it estimated transport costs (by subtracting reported export value from reported import values), and translated these values into carbon emissions, based on assumptions about the emissions intensity of different transport modes. It covered land, air and shipping emissions.

This approach indicated that 14% (12 Mt CO2) of Sweden’s total CO2 footprint  came from transport activities in 2011, and most of these emissions – 7.8 Mt – were linked to transport activities embodied in goods consumed in Sweden, rather than the direct consumption of transport services in Sweden (4.2 Mt).

A Big Data approach to estimate GHG emissions from maritime shipping

The second approach – which covers maritime shipping emissions – links regular automatic signals indicating the location, speed and other operational data for each vessel, with characteristics of each ship, and details of their cargo content. This allows very accurate carbon emissions assessments per vessel and commodity transported for each country of origin and destination.

This bottom-up approach found that in 2016, vessels departing or landing in Sweden emitted 2.66 Mt CO2, in 21 098 journeys. The main routes, in descending order of associated shipping emissions, were to and from Germany, the UK, Russia, domestic, Netherlands and the USA.  As well as producing aggregated emissions per country or type of vessel, the approach can also allocate emissions to individual commodities, companies (exporters and importers) and ports.