BOSTON - Despite significant progress in curbing greenhouse gas emissions over the past decade, smog and soot pollution continues to create health concerns in Massachusetts, according to a new environmental survey.

Cities and towns around the state experienced 304 "dirty air days" in 2015, according to the report released by the Environment Massachusetts Research and Policy Center. Residents in Boston endured 41 days of elevated smog pollution and 92 days of elevated soot pollution.

"We clearly need to make this move and transition away from our dependence upon fuels from hell - coal, oil and gas - to a new economy based upon fuels from heaven, solar and wind in particular," said Northeastern University professor Daniel Faber, director of the Northeastern Environmental Justice Research Collaborative.

Environment Massachusetts presented its findings at the State House where it brought a group of two dozen students to lobby legislators on clean energy bills, including one filed by Arlington Rep. Sean Garballey calling for Massachusetts to achieve 100 percent renewable energy by 2050.

Greenhouse gas emissions, which are blamed by scientists for climate change and can also contribute to health problems like asthma and heart disease, dropped 21 percent below 1990 levels in 2014, according to the state. The drop was attributed to state policies promoting clean energy and efficiency, as well as weather conditions, economic conditions, and relative fuel prices.

Under the state's Global Warming Solutions Act, emissions are required by 2020 to be 25 percent lower than 1990 levels. Rep. Mike Connolly, a freshman Camridge Democrat, said gains to date show that the goal is "achievable," but should not be the end of the debate.

"We want to get to zero emissions. We want to get to zero fossil fuels," Connolly said.

Meghan Hassett, campaign organizer for Environment Massachusetts, said the report did not compare the number of "dirty air" days in 2015 to past years, but said it cold be assumed that the numbers are lower and decreasing.

"Keep them going down," said Boston University Professor of Environnmental Health Richard Clapp.

Hassett also renewed the group's call for Gov. Charlie Baker take the lead in pushing his fellow governors in New England and the mid-Atlantic states that are part of the Regional Greenhouse Gas Initiative to double the emission reductions targets.

Baker last summer signlaed support for doubling the annual reduction targets to 5 percent starting in 2021, but more recently has been less direct about his preference as he works with other states to extend the regional climate change partnership.

"With action at the federal level stalled, it's time for Gov. Charlie Baker to follow through on his commitment to strengthen the Regional Greenhouse Gas Initiative to protect our health and our climate from dangerous power plant pollution," Hassett said.

The Trump administration's plans to rewrite the Obama-era Clean Power Plan, scale back funding for the Environmental Protection Agency and roll back federal clean car standards mean that states will have to take a leading role if clean energy policies are to advance, said Patrick Kinney, a professor of urban health at Boston University.

Kinney said global warming has resulted in a longer smog season, and increased its intensity on hot days, while also making wildfires more frequent with the capability of causing pollution that can extend hundreds of miles.

In addition to Garballey's bill (H 3395/ S 1849), the students planned to lobby lawmakers on a bill filed by Rep. Paul Mark and Sen. Jamie Eldridge (H 2706/ S 1846) that would eliminate caps on solar net metering and set a goal of 25 percent solar electricity by 2030; Connolly's bill (H 3390) to promote new construction suitable for solar installations; and a Rep. Russell Holmes and Sen. Sonia Chang-Diaz bill (H 3396/ S 1831) to promote low-income solar.

Faber called carbon pollution one of the most significant social justice issues facing the public health health community.

He said Boston ranked as the fifth worst city in the country for racial disparities in exposure to air pollution in a recent University of Minnesota study, with people living in communities of color at a much higher risk of breathing contaminated air.