By MICHAEL P. NORTON

State House News Service

In 2015, greenhouse gas emissions in Massachusetts were 19.2 percent below emissions in 1990, according to newly updated inventory data.

The Executive Office of Energy and Environmental Affairs data, released on Thursday afternoon, also includes preliminary data for 2016 predicting reductions of 20.8 percent below 1990 levels.

"The updated inventory utilizes an approach consistent with that taken by the U.S. (Environmental Protection Agency) and other states and countries, and reflects progress to implement greenhouse gas reduction strategies under the Global Warming Solutions Act," the Department of Environmental Protection wrote in an email to stakeholders.

"Fluctuations in emissions can be attributed to weather, including the historically cold and snowy winter the Commonwealth endured in 2015 which increased usage of carbon-intensive energy generation," the department said. "Additional variations can be attributed to market forces and increases in transportation sector emissions."

Massachusetts is chipping away at emissions through measures included in its Global Warming Solutions Act and clean energy laws approved in 2016 and 2018, as well as through emissions reductions being achieved through the multi-state Regional Greenhouse Gas Initiative. Efforts are also underway to promote the use of zero-emission vehicles and more broadly tackle the problem of emissions generated in the transportation sector and by building and facility systems.

State officials are developing a long-range comprehensive study outlining strategies to achieve 80 percent reductions by 2050, a study that the executive branch says will feature a "rigorous sector by sector analysis of plausible pathways for Massachusetts to meet the 2050 emissions limit while continuing to grow the economy and meet the overall needs of society."

The pace of emissions reductions continues to generate contentious debate on and off Beacon Hill, where lawmakers are weighing environmental benefits with concerns over energy reliability and affordability.