Each year in Los Angeles, certified green buildings keep 319 million pounds of greenhouse gases out of the atmosphere โ€” the equivalent of not burning 155 million pounds of coal or having the entire city go vegan for two weeks.

These findings from UCLA researchers, published today inย Nature Energy, are part of theย first studyย to examine the effectiveness of green building certification programs on a large scale. Researchers analyzed 178,777 commercial buildings using data from theย L.A. Energy Atlas, a UCLA project that combines utility data, census information and details about buildings โ€” their age, size and whether theyโ€™re used for residential or commercial purposes.

โ€œWe found that with the labels there is a significant improvement in energy efficiency,โ€ said Magali Delmas, an environmental economist and member of theย UCLA Institute of the Environment and Sustainabilityย who co-authored the study with institute postdoctoral researcher Omar Asensio.

The energy supplied in buildings accounts for 8.8 gigatons of carbon emissions globally and one-third of global carbon emissions, the study notes. Compared to other commercial buildings, those certified byย LEED,ย Energy Starย and theย Better Buildings Challengeย saw energy savings improvements ranging from 18 to 30 percent, depending on the specific program.

Thatโ€™s good news for those seeking to reduce emissions and battle climate change, but, Delmas said, it comes with a major caveat: the programs had almost no impact on medium- and small-sized buildings, which account for roughly two-thirds of all commercial structures in Los Angeles.

The one-size-fits-all, engineering-heavy approach of major certification programs may not be a good fit for small building owners, said David Hodgins, executive director of the L.A. Better Buildings Challenge.ย A program with options that can be tailored to individual needs might work better.

Making small business owners aware of the program is another challenge. Hodgins thinks community groups, nonprofits, faith-based organizations and small business councils could play an important role in getting more to participate. โ€œA lot of these smaller buildings are going to be family owned,โ€ Hodgins said. โ€œPart of the pitch should be that weโ€™re going to make sure the building doesnโ€™t become obsolete so it will benefit your children and grandchildren.โ€

Rives Taylor is a sustainable buildings expert with Gensler, an international architecture firm. He said that even among larger buildings, less than 10 percent commit to getting certified. But when they do, it makes a big difference in the results.

โ€œThereโ€™s absolutely no question that a third-party tool makes it happen,โ€ Taylor said. The external requirements and the reward of getting certified provide incentives for engineers and builders. Without them, important engineering details and building materials usually get sacrificed, he said.

Firms willing to invest in green buildings often see quick returns in the form of energy savings, recouping their initial investments within a couple of years, Taylor said. Building owners have also become more interested in how sustainable buildings affect employeesโ€™ health. Such benefits can be hard to translate into numbers, but they have long-term effects for quality of life.

โ€œYou would think it would have been a no brainer,โ€ Taylor said. โ€œBut for the last 20 years, no one would believe that improving a buildingโ€™s air quality, daylight or views would do much for well-being. Only in the last handful of years have we seen data that starts to sway those who spend money.โ€

Thatโ€™s where research like thisย new study can make a difference. UCLAโ€™s Delmas said having more concrete data โ€” including information about energy use โ€” is the first step to get more buildings to participate in green certification programs.

โ€œWe need more transparency,โ€ Delmas said. โ€œIf you donโ€™t know about your usage, how can you change it? If you donโ€™t know that your building is using 10 times more energy than the one next to you, how can you make adjustments?โ€

The study notes that the United Nations Environment Program and energy experts argue that the buildings sector has the largest potential to deliver long-term, cost-effective reductions.

For that to happen, certification programs will need to expand โ€” a possibility that suffered a big setback with President Donald Trumpโ€™s recentย budget plan. Experts in green business and energyย raised alarmย that Energy Star was marked for elimination as part of the presidentโ€™s proposal to slash Environmental Protection Agency funding by 24 percent. But the budget process is just getting started, and many lawmakers expect the elimination of the popular program to face resistance in Congress, even among Republicans. [UCLA]