SAN FRANCISCO, Nov. 7 (Xinhua) -- San Francisco residents need to pay attention to potential threats to the environment, including the negative impact of fossil fuel extraction and climate change, indigenous activists said here on Wednesday.

Melinda Micco, sounded the call at a seminar held for San Francisco residents at Exploratorium, a science museum in the waterfront neighborhood of Embarcadero in San Francisco.

Micco, who is one of the three speakers at the seminar, expressed particular concern about the fragile nature of refineries in the United States and other countries, which pose a threat to both the environment and communities, including the Indigenous people.

"The massive thing right now for us in this area are the refineries and how fragile they are," she told Xinhua, citing the powerful explosion of a leaking propane pipeline in Maine in September that killed a firefighter and leveled a new building,

She said that while she was doing a film on the environment, she found that more explosions have occurred in the last 15 to 20 years than in the 30 years before.

Micco expressed her opposition to fossil fuels, saying she supported a transition toward more sustainable energy sources.

"The renewable energy sources industry can actually employ more people," she said at the seminar organized by a local indigenous environmental movement.

She admitted that it may take more time and a huge amount of work to realize a world dependent on cleaner energy. However, "We have no other option, you have to go forward with that and try to make adjustments," she said.