Trying for a leaner, meaner approach to its sustainability goals, the Palo Alto City Council approved a four-pronged revision to its 2018-2020 Sustainability Implementation Plan on Monday night, which will initially focus on reducing carbon dioxide and protecting potable water sources.

By a vote of 8-0, with City Councilman Adrian Fine absent, the council adopted the changes and also directed staff to return in early 2018 with a discussion on fossil-fuel divestment.

The city's overall goal, which the council unanimously approved in April 2016, is to reduce greenhouse gases by 80 percent from 1990 levels by 2030. The 2018-2020 plan presented Monday came out of a more detailed one that city staff had presented on June 5, which included more than 40 new programs and policies.

Staff estimated the narrower focus on four actionable areas -- energy, mobility, electric vehicles and water -- could enable the city to reduce greenhouse gases to about 40 percent below the 1990 base year by 2020 and by about 54 percent if natural gas offsets are included. The city's goal far exceeds California's reduction goals of 40 percent by 2030 and 80 percent by 2050, staff noted.

About 66 percent of greenhouse-gas emissions in the city are from transportation, Palo Alto's Chief Transportation Official Joshuah Mello said. Targeting that area of pollution, the pared-down sustainability plan would reduce the number of people driving solo in the city by providing incentives to change behavior, would build out the city's bicycle network and increase pedestrian and bicycle safety. The staff plans to bring bike-share regulations forward early next year and to expand its shuttle programs, he said. Staff would also start tracking public-transit ridership and the rate that employers participate in alternative-transportation programs.

The city would also try to increase people's purchase and use of electric vehicles. In 2015, more than 15 percent all vehicles bought in Palo Alto were electric vehicles, staff noted, adding that 4,000-6,000 electric vehicles will be purchased in the city by 2020. To support the shift, the city will have to figure out how to accommodate those changes. Staff will focus on expanding its electric-vehicle charging stations on public property and in private spaces. The need is already being addressed through additional charging stations and solar panels in public parking structures this year, for example.

But the city must also look at costs associated with building that infrastructure; leveraging private sources for expanding the network could also be part of the strategy. Staff recently became aware of a program by the private sector to approach multifamily property owners about adding electric-vehicle charging stations, for example.

Mayor Greg Scharff said that forcing multifamily housing complexes to install charging stations would allow residents to plug in their electric vehicles at home overnight -- a key incentive. Staff said they would look at ways to encourage the addition of electric-vehicle stations when buildings are upgraded.

Staff said that emissions from natural gas represent about 25 percent of the city's remaining carbon footprint. The plan focuses on improving energy efficiency in new and existing buildings, for example through mandatory energy efficiency and pilot programs for efficient appliances. It would encourage building owners to convert from natural gas to electric equipment and continue the city's own power conversation from natural gas sources to electricity. Staff said a goal is to complete construction of a replacement facility for sludge incinerators, which consumes the most energy of all city facilities.

Multiple members of the public implored the council members to divest the city from fossil fuels. Councilman Cory Wolbach moved to pass the pared-down sustainability plan, but said the council should direct staff to prepare for discussion of divestment from fossil fuels early next year.

"It is time to move that conversation forward," he said, adding that he wanted staff to identify a timeline for that divestment.

More than a dozen public speakers also asked the council to legislate an end to groundwater pumping. In its list of water-conservation goals, staff identified protecting groundwater in creeks and the San Francisco Bay, but it did not specify ending groundwater pumping in its list of "key actions." Instead, staffed focused on developing programs and ordinances related to water efficiency and use of grey water, stormwater and recycled water and on finding ways to capture stormwater and restore it to the natural ecosystem.

In presenting the slimmed-down implementation plan as directed by the council, city staff is not dropping the remaining areas in the previous iteration of the sustainability implementation plan: zero waste; municipal operations; climate adaptation and sea level rise; regeneration and natural environment; financing strategies; community behavior, culture and innovation. Those would be included in future plans, staff said.

In the presentation, staff asked the council to accept the revised plan now with the understanding that if future funding requests are not approved some of the actions won't be undertaken. The overall sustainability plan's progress will be evaluated every three years beginning in 2020.