A recently published study has found that wildfires and deforestation have contributed more to greenhouse gas emissions than previously expected.

The study, published online in the journal Forest Ecology and Management on Wednesday, was a collaborative effort between researchers with UC Berkeley and the U.S. National Park Service that assesses the amount of carbon stored and released in California ecosystems.

The research could shed light on goals established in California’s mandated Global Warming Solutions Act, or AB 32, which requires the state to reduce greenhouse gas emissions to 1990 emission levels by 2020. The act was passed in 2006.

Lead author and U.S. National Park Service climate change scientist Patrick Gonzalez, who analyzed data to conduct an integrated analysis of ecosystem carbon across California, said the findings show that while California forests and other wilderness areas contain large stocks of carbon, wildfires reduced the stocks from 2001 to 2010.

“Before our research, it had not been clearly known whether California ecosystems were storing carbon and reducing climate change or emitting carbon and making climate change worse,” Gonzalez said in an email.

According to Gonzalez, a century of fire suppression has caused the “unnatural buildup of dead wood and thicker stands of small trees,” providing more fuel for fires. These changes have then contributed to recent instances of particularly large and severe wildfires.

Gonzalez said that meanwhile, climate change has been increasing both temperatures and conditions that cause wildfires.

UC Berkeley professor of forest ecology John Battles, who participated in the research, said the overall goal of the study was to assess if carbon was being stored or lost in California wildlife.

While plants absorb carbon dioxide and the wilderness areas of California store a lot of carbon, the areas have lost carbon over the last decade. Battles said the main culprits are wildfires.

“We’re hoping (AB 32) could spur tech innovation,” Battles said. “California is often at the forefront of implementing green laws, such as fuel efficiency.”

Gonzalez said that California has the “practices and technology” to become more energy-efficient and that with a combination of science, policy and public support, California can reduce the effects of climate change.

When considering whether California can reduce its greenhouse gas emissions to the 2020 targets, Battles named two significant factors: the fire season being aggravated by a warmer and drier climate and California’s policies on fire suppression and forest management.

Gonzalez said that if people do not reduce greenhouse gas emissions from “cars, power plants and other human sources,” climate change could drive an increase of one-third to three-fourths in wildfire frequencies across much of the state.

“It’s a big state with a lot of forest with a problem that’s been growing for a while,” Battles said.