BOSTON (SHNS) – When it comes to climate change policy, there are two parallel tracks at play on Beacon Hill: one focused on implementing the climate law that Gov. Charlie Baker signed in March, and another focused on passing legislation to set even more ambitious goals than the ones that just became law.

After taking a long, winding and sometimes contentious road through all of the last legislative session and the earliest days of the current one, the governor in March signed long-discussed legislation designed to commit Massachusetts to achieve net-zero carbon emissions by 2050, establish interim emissions goals between now and the middle of the century, adopt energy efficiency standards for appliances, authorize another 2,400 megawatts of offshore wind power and address needs in environmental justice communities.

During separate but back-to-back virtual events Tuesday, Energy and Environmental Affairs Secretary Kathleen Theoharides explained what the Baker administration is focused on as it begins to implement the law and then a handful of lawmakers and advocates made their case for why the so-called climate roadmap law is not enough.

Jacob Stern, Massachusetts chapter deputy director for the Sierra Club, said the roadmap law is “an excellent first step that charts the path for us” but that a bill up for consideration this session that would require the state get 100 percent of electricity from clean and renewable sources by 2035 and use 100 percent clean transportation and heating by 2045 is “the vehicle, or the electric vehicle, that’s going to get us there.”

“It lays out real tangible steps to address energy sourcing in each of our economy’s main emissions-producing sectors as well as reducing harmful pollution, providing direction for assisting workers who will be displaced by the transition from fossil fuels, and of course, ensuring equitable deployment of clean energy technologies,” Stern said, noting that he had just listened in on the webinar that featured Theoharides.

The legislation (H 3288/S 2136) filed by Reps. Marjorie Decker and Sean Garballey and Sen. Joe Boncore has not yet been scheduled for a hearing before the Joint Committee on Telecommunications, Utilities and Energy. It has 13 Senate co-sponsors and 63 House co-sponsors, according to Environment Massachusetts.

The bill would require investor-owned utilities to provide 100 percent clean electricity by 2035, with at least 80 percent coming from Class I resources through the state’s renewable portfolio standard. Municipal utilities would also be required to provide 100 percent clean electricity by 2035. New buildings would be required to be built without fossil fuel heating, Environment Massachusetts State Director Ben Hellerstein said, and all new cars sold after 2035 would have to be electric vehicles.

“I think a really important piece of the bill … is ensuring a just transition for workers and environmental justice communities,” he said. “And so the bill would establish a couple of offices within state government to make sure that workers and EJ communities are included in the transition to renewable energy, and it would ensure as well that public hearings are held in EJ communities and that folks have the opportunity to participate and make their voices heard in these decisions.”

When Hellerstein first sat down with Decker and Garballey in 2016, he said, Hawaii was the only state in the country that had passed a bill requiring 100 percent renewable electricity. Since then, he said, seven other states, Washington, D.C., and Puerto Rico have passed similar legislation and other states have set a similar goal through executive orders.

“I think we have some catch-up to do in terms of matching some of these commitments that have already been made in other states,” Hellerstein said. “But we can even go above and beyond as well and really reclaim our role as a leader in clean energy, and that’s really what this bill would enable us to do.”

During an earlier virtual event hosted Tuesday by the sustainability-focused nonprofit Ceres, the state’s top energy and environment official said she thinks the greatest challenge when it comes to wringing out greenhouse gas emissions will be dealing with the many old and inefficient buildings around the state.

“The building sector definitely represents a big challenge here in Massachusetts, where we have really old building stock. So leaky, energy inefficient, coupled with about seven months of a heating season and then, increasingly, a cooling season,” Theoharides said. The secretary added, “I think one of the key challenges is getting into homes and businesses and large commercial spaces and industrial spaces across the commonwealth, and really making sure they are built to use as little energy as possible, retrofitted to use as little energy as possible and, where we can, to significantly ramp up electrification.”

While some of the earliest work to implement the new law is ongoing — the first interim plan required by the new law must be in place along with the 2025 emissions limit by July 1, 2022 — Theoharides said the Baker administration will also convene a first-in-the-nation commission on clean heat, to look into ways to get people to adopt solutions like air source heat pumps and to set a declining cap on heating fuel emissions.

“We obviously have our work cut out for us,” the secretary said.

On Monday, the Department of Revenue’s Division of Local Services released its “initial guidance to local officials regarding changes in local property tax laws” included in the climate law that Baker signed at the end of March.

Among other tax-related provisions, portions of the law provide a property tax exemption for certain categories of solar- and wind-powered systems, authorize cities and towns to enter into payment in lieu of taxes agreements with the owner of a solar- or wind-powered system or energy storage system, and create a new property tax exemption for “qualified fuel cell powered system, the construction of which was commenced after January 1, 2020, that is capable of producing not more than 125 per cent of the annual energy needs of the real property upon which it is located.”