Consultants present emissions 'wedge' forecast showing major remaining role for natural gas

Cascadia consultants presented a future greenhouse gas forecast and wedge analysis to the City of Lake Forest Park's Community Planning Advisory Panel on the city’s preliminary emissions pathways and the remaining gap local policy must fill.

Alicia Purnell, with the Cascadia team, said the analysis compares three scenarios against the city’s targets: a business-as-usual (BAU) projection using 2019 as the baseline, an adjusted BAU that includes expected federal and state policies, and a local-action scenario that models the effects of draft climate element policies. “The BAU scenario projects emissions would increase about 26% by 2050 compared with 2019,” Purnell said, while accounting for federal and state measures reduces projected emissions roughly 56% by 2050. Adding the draft local policies reduces projected emissions to about 65% below the 2019 baseline by 2050, she said.

The presentation highlighted a persistent “emissions gap” between the projected trajectories and the city’s reduction targets. Purnell said natural gas used in buildings is expected to be the largest remaining emissions source: “By 2050, natural gas is expected to make up about 92% of remaining emissions,” she said. The consultants flagged that filling the gap will require stronger policy action at one or more levels of government.

Panel members asked for clarification about how the model treats federal and state actions. Purnell explained the ABAU scenario incorporates currently expected state and federal policies but assumes compliance and noted that federal policy outcomes remain uncertain; she recommended communicating that uncertainty in the analysis and accompanying memo. A panel member also asked whether the dotted wedges on the graphic represented the draft local climate element policies; Purnell confirmed they represent the assumed impacts of the current draft local policies, while the larger gray area indicates emissions not yet addressed.

The consultants said they are recommending a 2019 inventory baseline because it is a recent year for which the city has inventory data and that other comparable cities use similar baselines. They also said they will produce a summary memo documenting modeling assumptions, the policies included in the ABAU, and additional detail on the wedge analysis for panel review.

Next steps identified in the session included vetting model assumptions with city staff and refining the draft climate element policies; the consultants said they will provide a written summary memo with more detail for panel members to review.

The presentation and questions occurred during the CPAP meeting when the consultants introduced the future emissions forecast and wedge analysis and before the panel moved into a detailed review of draft goals and policies.