Consumption based options to reduce GHG emissions Leiden University, CML: Joao Rodrigues, Valentina Prado, Ester van der Voet NTNU: Dan Moran, Richard Wood Most climate change mitigation policies target production sectors. While these do cover a significant part of the GHG emissions further reductions could be achieved by implementing consumer oriented policies – in addition to existing ones. Consumption based policies can combat use phase emission currently not addressed by current policies; AND by taking a life cycle approach, these consumption based policies target all the supply chain thus evaluating sources of emissions within and outside of the EU. Ill talk briefly about how we evaluated the GHG reduction potential of consumer based options. This was an effort by researchers at Leiden University and the Norwegian University of Science and Technology (NTNU).

Context First step ins scenario analysis Focus in technical potential No rebound effects at this stage Focus on GHG Results relative to total EU GHG footprint Prior to continuing with the results, Ill like first point out where this evaluating takes in places in relation to the whole project. This was done as a step in scenario analysis, the focus here was the technical implementation and to explore the environmental potential of each option, not actual uptake rates. Potential reductions estimated at this point do not take rebound effects, this is something that is done later on in the project. Also, it is good to note that we focus in GHG, no other environmental indicator. Results are shown relative to EU’s GHG footprint

To asses GHG mitigation potential of consumer based options in the EU Goal To asses GHG mitigation potential of consumer based options in the EU Two fold approach EXIOBASE MR-EE input-output table used for calculations 1 2 84 options Quickscan There are many consumer based options that have been identified in the literature, mostly by assessments done in an individual basis. The aim (and challenge) here, was to evaluate the potential of these options in an European scale. Therefore, going from one individual’s change of diet, to the entire continent. There were a total of 113 options ranging from electric vehicles, to changes in diet. Sectors included: transportation, buildings, textiles, electronics… To assess the GHG mitigation potential of these options at a regional scale, we used an Environmental Input Output (IO) approach as it enables relatively fast assessments at a large scale. We did this in two steps: quickscan and a detailed analysis. some of these options were not able to be analyzed with an IO approach. The reason, was due to overlap as the economic sectors may not help distinguish between alternative that are too similar. Such as different type sof plastics and so on. Thus, 84 options made it to the quickscan, out of which we performed a more detailed analysis on 30. 30 options Detailed Analysis

About the Quickscan Translate 84 options in terms of EXIOBASE Final demand reduction Efficiency improvements in the processes of the supply chain: changes in coefficients Changes in the supply chain: changes in structure Upcoming publication by NTNU and CML in this methodology These are the main parameters that go into the quickscan. Each alternative is translated into changes in demand, efficiency improvements, or changes in the supply chain More details can be found in an upcoming publication.

Quickscan Results 48% 34% Results for the quickscan per sector look like this. The x-axis shows the type of options implemented. For example, all options in transport, or all in buildings. The Y-axis, shows the reduction potential in terms of the total EU CO2 footprint consumer based options have a potential to reduce GHG . Transport, buildings and food show the most potential. 20%

Quickscan Results ~10% If we take a look at the CO2 savings of individual alternatives and the place of emissions – in and out of EU, we see that trasnpaortation related options have the most potential. Public transport, cycling, walking, car sharing, zero emission houses are among the most promising options.

Detailed Analysis Detailed analysis Options from transport, building, food Modifications in structure and coefficients based on literature Country specific inputs and results Hybrid LCA - more detail in sectors - full hybrid analysis using EXIOBASE as background system We gather the most promising alternatives and perform an evaluation in greater detail. Here, we use country specific information to estimate change coefficients as well as single LCA studies. For demonstration purposes, I will focus in the building alternatives

Detailed: building These were the 5 options with most potential in the building sector according to the quickscan. For these, we used EU statistics on residential energy demand, living conditions as well as type of housing per each country. For example, Passive Houses have a standard that limits its primary energy demand to be 120kWh/m2. Given this limits, and existing primary demand per m2, we can then estimate a reduction coefficient. In addition, according to the literature, passive houses have the most potential in detached homes. Thus, we modeled this intervention in a fraction of the housing stock. Achieving a Passive House standard requires of additional investments in the construction phase as it needs more thermal insulation and ventilations systems. The additional costs are estimated according to literature and scaled up within each country.   Net Zero Energy Building (NZEB) go a step beyond passive houses and supply remaining energy with renewable energy on site. Here, we can see whether there are some gains to further reducing use phase residential energy. Thermal insulation was modeled by estimating space heating savings from a wall insulation specification. We assumed that thermal insulation can be implemented in the entire stock, thus this is implemented in flats s and single family homes as well. Timber frame evaluates the effects of building with timber frame as opposed to concrete and steel. Some of the foreseen benefits is that the timber is less energy intensive to manufacture and it is lighter, thus reducing transportation emissions. This intervention took place in detached family homes as existing regulations and expertise is still relatively novel for multi-story timber construction. This potential was evaluated by substitution rates. More timber, less concrete and less steel. We also took into account the share of homes that already have a timber frame – which is much higher in the Nordic regions. These are the main factors defining this option. Finally, the thermostat option evaluates the effects of a 2 degree reduction. Studies estimate approximately 10% savings in space heating per degree reduction. We modeled this in the whole residential stock.

Building Results Passive House With a country specific analysis we see that in absolute terms, countries with largest population (Great Britain, Germany and Poland) contribute the most to these savings. We also identify that in terms of per capita, the effectiveness of each option is very different. This can inform policies that are more aware of differences between countries. The most beneficial alternative is not the same for every country.

Transport Results Now the transportation results. The x-axis shows the individual alternatives, the primary y-axis the total savings (or increase) in terms of their place of occurrence. All alternatives result net savings as shown in the secondary y-axis. Hydrogen cars has the most savings with 20%, electric cars, 18%, Carpooling 11% and Public transport 10%.

Food Results 5,5% Lastly, the food options. Reducing waste and reducing meat consumption were the two most promising options in terms of CO2 savings. Savings occur about half in and out of the EU. Now, these results only look at the environmental potential, whether or not you can actually incur a change in behavior is a different question.

Conclusions Large potential for consumption based GHG reduction Twofold approach practical for a large number of diverse options GHG savings in Buildings

Thank you!

Transport Results

Building Options Passive Houses: kWh/m2 standard, implementation in single family homes NZEB: Passive house WITH renewable energy on site Thermal Insulation: U-Value of wall insulation Timber frame: single family homes. Substitution rates Thermostat temperature: reduction in space heating