Linda Adams, secretary for environmental protection of the California Environmental Protection Agency, spoke at the Green California Summit and Exposition on Tuesday about increasing green development during tough economic times.

"‘Green' is a much-used term these days," Adams said. "It's a frame of mind."

She said California is the first state to actively engage the United Nations on the topic of sustainability, and that the state's goal is to reduce its greenhouse gas emissions to the levels they were in 1990 by 2020.

Dan Kammen, director of the University of California, Berkeley Renewable and Appropriate Energy Laboratory, also spoke about how the country needs diverse, measurable cases of low-carbon development. He said 20 percent of California's energy is used to move water, and although there's not carbon embedded in the water, carbon's used in the processes of moving and cleaning water. Processes like these must be re-examined.

He also said the country needs to unlearn its old thinking of things like solar energy. Technology is allowing traditional thinking to be undone. Kammen's example was that solar panels no longer must be linked together to gain the most efficiency. Traditionally when people think of installing solar panels on their roofs, they imagine them side by side. However, through the use of microinverters -- which attach to the back of each solar panel and convert the panel's power current -- solar panels work individually to capture power and can be more efficient.

Kammen also mentioned a carbon footprint calculator created by UC Berkeley to help households calculate their annual carbon-dioxide emissions.