Mark Hertsgaard, a journalist who has written for The New Yorker, National Public Radio, TIME Magazine and Vanity Fair, warned Thursday of the rising environmental dangers of the changing world climate, as well as the Bay Area’s advantage in addressing the issue, at the fifth annual Town & Gown Conference.

In his speech at the conference — a two-day event featuring college and city representatives from throughout the state held in Hotel Shattuck Plaza in Downtown Berkeley — Hertsgaard emphasized the risk from rising sea levels that could potentially submerge San Francisco and Oakland in the next 50 years.

He discussed the Bay Area’s advantages in having a society that does not dispute that climate change exists.

“We also have business and economic leaders who, far from resisting (climate change), are embracing the idea that we need to have clean energy as a response to climate change,” Hertsgaard said.

Water levels in the San Francisco Bay have risen nearly eight inches over the past century, and sea levels could rise 10 to 17 inches by 2050 and 31 to 69 inches by the end of the century, according to the San Francisco Bay Conservation and Development Commission.

“We are going to lose the snowpack atop the Sierra Nevada Mountains,” Hertsgaard said. “That snowpack was responsible for about 25 percent of freshwater in the state.”

Hertsgaard said overconsumption also plays a great role in carbon emissions that result in ecological footprints.

“The average American child will leave an ecological footprint 108 times a child born in Sierra Leone,” Hertsgaard said.

He also mentioned many environmental leaders from the Bay Area, including Steven Chu, former UC Berkeley physics professor, who served as the 12th U.S. Secretary of Energy.

“We’ve got also a political tradition here where the environment is a bipartisan issue,” Hertsgaard said.

He commended former Gov. Arnold Schwarzenegger for his environmental policies, such as the $11 billion proposal for water bonds to invest in future water flow and his fight against Proposition 23, what Hertsgaard described as a push from oil firms to suspend the Global Warming Solutions Act of 2006 that set out to cut greenhouse gas emission levels.

“Climate change is not just an environmental issue … our business people now recognize that climate change is an economic imperative,” Hertsgaard said.

Social, political and economic forces are moving the Bay Area more toward clean energy and conservation of energy, he said.

“The challenges we face about the climate are so great that we can only master those challenges if we leverage the advantages that we have,” Hertsgaard said. “The plea as the father of a six-year-old: help make it the future that we can have rather than the future that we are afraid of.”