BOSTON -- Massachusetts is pursuing one of the nation's most ambitious climate change plans that will require substantially reduced greenhouse gas emissions from homes, offices and vehicles over the next 30 years.
But data that environmental officials use to gauge whether those efforts are successful lags behind years, which is complicating the work of policymakers as they seek to address climate change.
The state Department of Environmental Protection's most recent baseline study of greenhouse gas emissions dates back to 2016. A federally required inventory of air pollutants emitted within the state, released in 2018, includes data from 2011.
Meanwhile, the most recent data on diesel fuel emissions is five years old.
Last week, Gov. Charlie Baker signed a sweeping climate change bill that requires the state to take steps to meet benchmarks every five years toward a 50% reduction in emissions by 2030 and net-zero emissions limit by 2050.
Sen. Mike Barrett, D-Lexington, a co-chair of the Joint Committee on Telecommunications, Utilities and Energy, who co-authored the bill, says up-to-date data is crucial for the plan to succeed.
"We're taking note of the incredible lag time that has been involved in reporting back to the Legislature on whether we are curbing emissions," Barrett said during a recent Joint Way and Means Committee hearing. "We need to provide that data in a much more time-relevant way than has been the case."
Barrett said the the new climate law requires the state Office of Energy and Environmental Affairs to provide lawmakers with an update on emissions levels every 18 months "so that we're not looking at 2017 numbers in 2021."
Martin Suuberg, commissioner of the state Department of Environmental Protection, acknowledges that the state needs more timely data.
"We're constantly trying to make sure that we're looking at the most up-to-date information and providing it in as timely a way as possible," he said recently.
Suuberg pointed out that the state gets the bulk of its emissions data from the federal government. In some cases figures can be updated more than a year later, as the federal government makes adjustments to its models, he said.
Environmentalists also acknowledge that the lag time on data makes it harder to gauge whether the state is hitting its targets.
But Elizabeth Turnbull-Henry, president of the Environmental League of Massachusetts, says that shouldn't be a reason to back off efforts to address climate change.
She said "time is running out" to reduce emissions that scientists say are contributing to melting ice caps, rising seas and devastating storms.
"There's always going to be a data lag in environmental reporting," she said. "But that's not an excuse to lower the aim of our ambitions."
Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group’s newspapers and websites. Email him at firstname.lastname@example.org