Sacramento, CA


There were two separate energy scenario sessions carried out for SACOG. The results of these are presented over the next pages.

These scenarios look at how a CO2 emissions reduction of 80% may be achieved in the SACOG area by 2050. These scenarios were all run using the Greenhouse Gas Regional Inventory Protocol’s approach to scenario formation. The sessions were all interactive and sought a balance between the qualitative and quantitative elements deemed most pertinent when forming an energy emissions scenario.

The scenarios for SACOG were produced with 21 different stakeholders from a variety of interest groups and backgrounds, put together through SACOG’s contacts. The scenarios reflect the inputs from all of the stakeholders as to how SACOG may reduce its CO2 emissions by 2050, however they should not be deemed representative of any individuals view.

Neither of the scenarios achieved the desired 80% reduction in CO2 emissions. The scenarios both showed end-user energy consumption declining by 4% in one and 34% in the other. These reductions varied by sector in each of the scenarios. The most noticeable difference was the reduction of non- electrical energy consumption in the domestic sector which was deemed to reduce by 40% in Scenario 1 but remain unchanged in Scenario 2. When considering this, it should be noted that the sessions were run independently of each other.

In both scenarios economic growth was running at an average annual increase of at least 2%. Moreover, both the population of the SACOG and the amount of households increased in both of the scenarios. In one scenario the population increased to just over 3million, in the other to over 4million. However, in one scenario the amount of households increased to 1.6million and the other 1.7million – a seemingly modest difference considering the difference in population growth. Indicating that average household size is greater in the former scenario.

The reasons described by the stakeholders for the decoupling of economic factors, CO2 emissions
and energy consumption varied between the two scenarios. However, they were predominantly driven by regulatory measures.

In both scenarios the public and regulatory bodies were deemed to have an active role in reducing the demand for fossil based energy and increasing the efficiency of the activities of different parts of the economy. As a consequence in scenario 2 there was a large focus on local production of energy from renewable sources. It is interesting to note that in both scenarios electricity production, from the distribution grid, was dominated by fossil based production - albeit using CCS. The production outside of the region varied between the scenarios – although nuclear power was present in both scenarios. In both scenarios electricity demand from the grid increased. However, it should be noted that scenario 2 was driven largely by an increase in electricity production from local renewable sources.

In both of the scenarios, the largest emissions reduction came from the road transport sector – this was 87% in scenario 1, and 80% in scenario 2. None of the other sectors, in either scenario, achieved a 80% reduction in emissions. Both scenarios saw domestic sector emissions declining by similar amounts of 76% and 74% respectively; indeed the level of reduction from industry was also similar at 53% and 57% respectively.

The scenarios did engage in a ‘backcasting’ dialogue, these can be seen in the charts on the respective pages – in scenario 1 this was taken as a mid-point between the baseline year and 2050. In scenario 2 this was the changes that stakeholders believed would be delivered by 2025 as a stepping stone to the energy scenario of 2050. This latter scenario showed a reduction in emissions by 2025 of 13%, with an increase in energy consumption. This would appear to be approximately in line with the California trajectory of reducing emissions to 1990 levels by 2020.

However, if SACOG’s emissions have increased since 1990 at the same rate as California then both of the scenarios may have met the wider Californian target. Furthermore, this target, due to the latest scientific studies, may need to increase from an 80% reduction in 2050, to a higher one. Additionally interim targets that are more stringent than the current 2020 targets may need to be set.

 This is because we need to be aware of the ‘stock of carbon’ in the atmosphere. The CO2 released now is likely to remain in the atmosphere for up to 100years. Increasing the global atmospheric concentration of greenhouse gases. We therefore need to be mindful of the sum of CO2 released over the next 40years (together with that released over the past twenty) in SACOG and California. As it is these emissions that are, and will be, the biggest cause of an increase

in concentration of CO2 in the atmosphere – rather than the CO2 emissions released in 2050. With this concentration being a key determinant of climate change.

These new targets may be informed by an array of academic studies that show how global emissions peaking at different times and the levels of warming associated with them. Such as those presented recently at the international climate conference in Copenhagen. In turn these understandings may inform planning policies regarding adaptation measures. If global concentrations of greenhouse gases increase beyond certain thresholds, global warming may occur that exceeds 2o celsius – potentially reaching 4o or even beyond. Some of the local impacts of such changes are highlighted earlier in this document.

The linkages between, total global emissions released over time, the associated atmospheric concentrations of GhGs and the potential associated climatic change are important as the impacts on the built environment of a warmer environment in SACOG maybe significant. Together with an understanding of the extremes in individual weather events that these global changes may bring to California and, in turn SACOG. This will require advance planning measures to minimize impact. An uncomfortable question may need to be asked, which is, if California does not meet the reductions that the latest science suggests are necessary to prevent a 2o rise – can it expect the rest of the world to do so? If not, perhaps planning needs to reflect this. Potentially this planning needs to find measures that both reduce CO2 emissions and increase California and SACOG’s adaptive capacity to deal with a significantly warmer climate future.

The scenarios are helpful as they show a distinct difference in the approaches taken by different stakeholder groups. They show the importance of dialogue in these matters so that a best way forward may be achieved, to meet the energy needs of the public and economy as well as delivering on the emissions reductions necessary for SACOG and California to play their parts in reducing global emissions. They also show the difficult task that mitigation presents. The scenarios presented here should be used to inform discussions.