These two memo’s outline the pitfalls of greenhouse gas emissions inventories and their usefulness toward (or rather their detraction away from) climate mobilization.
1/6/2018 – Memo on Greenhouse Gas Emissions Inventories – John Mitchell
This memo follows the argument against bottom-up vs. top-down estimates of greenhouse gas emissions (GHG) provided in the associated memo written on 10/18/2017.
The development of a city or county GHG inventory as a first step is unnecessary and antithetical to the concept of a WWII scale (decadal) transition to zero emissions.
The process of developing a GHG inventory takes a significant amount of effort and time, and if done correctly, is very expensive. The utilization of this inventory, once completed, is unclear but it is assumed that it will assist in the process of prioritizing and implementing emissions reduction policies.
Once the GHG inventory is completed and identified as a guiding document to the targeting of policies, the methodology of the inventory study is then opened up to challenge, in some cases a legal one. This is discussed more fully in the memo mentioned above. It is possible that successful legal challenge to the emissions inventory would invalidate it and lead to further work to develop one that is more acceptable. This would have the effect of stalling the actual implementation of emissions reductions policies by several years, at the least.
There are also issues that result from the use of the GHG emissions inventory as a guiding document. The use of an inventory in this way naturally lends itself toward a targeted emissions framework that is currently being promoted by the COP-21 “Paris Climate Accords”. This is already being observed in cities, counties and states today.
Through this process of identification of policies, developing acceptable targets and the projections of how to achieve these targets, there is also significant pitfalls that could ultimately invalidate the mitigation program. They are a result of basing the measured value of the policies on the projected impacts on the inventory and the pairing of least-cost efforts to those impacts. This process will inherently lead to bargaining which will reduce the incremental targeted goals, make the actual identification and adoption of policies much more time consuming and eventually result in a process of gradualism.
This incrementalism and gradualism must be avoided at all costs. It is already far too late to protract the aggressive emissions reductions that are already technically feasible and will necessarily result in massive local economic gains once implemented.
Instead of using a GHG inventory to guide policy, community and civic leaders should instead focus on the ‘big picture’ of fossil fuel use in their area. These fuels are so prevalent in their use that their identification is undeniable and the policies that can be used to offset them much easier to define. These cohesive policies work together across multiple sectors and with each other to immediately begin the shift away from fossil fuel consumption. For example, the implementation of city/green bank financing for rooftop solar buildouts paired with the implementation of a feed-in tariff for the energy generated from this system and subsidies for the purchase of electric vehicles for these homes.
Therefore any interim targets should be based only on the hard measurements of gasoline and diesel fuel consumption, with targeted reductions over the mobilization period, and new renewable energy generation as a percentage of total city or county electricity consumption from fossil fuel electricity generation sources.
10/18/2017 – Top Down VS Bottom Up Methodologies of GHG Inventories
Top down vs. bottom up refers to a measurement protocol of complex systems. A bottom-up methodology finds typical emitters and measures emissions from each one. These average emissions are then applied to the total population of emitters to receive a value of emissions. The more complex the system (say 200 different kinds of emitters) the more detailed the study must be to get an accurate assessment. However, when a very small percentage of the emitters may have a much higher amount of emissions, it is certain that this type of measurement will underestimate the total emissions since it is unlikely that they will be captured in the sample of measured sites.
For example, to perform a measurement of GHG emissions from all restaurants in Los Angeles, one could measure the emissions from 20 different restaurants of varying sizes and come up with an average value that could then be applied.
Of course, to get a city-wide emissions profile, one would have to look at every business and personal activity to get a profile of the total system. This is when the inclusion of activities like tourism or imported goods (or even meat consumption) could be very problematic, complex and expensive to measure. Consider that every different type of imported good has a different emissions profile and must be measured individually. However, this process is being performed on key imports like units of steel from China and Solar Panels. These kinds of studies of individual materials are called Life-Cycle Analyses (LCA).
A top-down estimate draws a boundary around the area that you want to study and finds out how much total fossil fuel is imported and burned. This process provides a reasonably accurate assessment with given assumptions (i.e. how much is not burned but spilled or leaked) and this is the process used by every major country and city to perform their GHG emissions profiles. However, key activities like the emissions associated with the production of goods and emissions due to transportation of goods are not included. Similarly, the emissions associated with the travel of visitors participating in the tourist economy are also not included, as well as many other examples of emissions that could reasonably be assigned to a city. There have been successful challenges to city emissions profiles based on these shortcomings and the solution to capturing these emissions produces a heavy burden on cities to quantify these emissions which is unfortunate since these additional emissions may be quite small compared to the total profile. For example, the City of Santa Rosa is considering how to quantify the emissions associated with their tourism industry. To do this successfully, they would have to require every visitor to fill out a survey to capture their travel-related emissions. (using a bottom-up methodology)
The problem with the incorporation of bottom-up methodologies from a city perspective is that they are time-consuming, subject to large uncertainties – and therefore have results that are less robust and easily challenged – and could lead to successful stalling of any actual efforts to reduce greenhouse gas emissions.
Therefore, at this stage of the mobilization, emissions profiles should be based on fossil fuel consumption and emissions associated with its production, transport and use. Later stages of mobilization will allow for more granular analysis as whole society engages in a national strategy.