Oil spills, water pollution, harmful pesticides: those are the types of contaminants that spurred environmental crusaders to initiate the first Earth Day in 1970.
Damage from industries, businesses and agriculture was noticeable, from thick sludge in landfills that bordered homes to unnatural plumes of green smoke that were emitted from spraying farms. As Earth Day approaches its 42nd anniversary, what's potentially the biggest threat to the environment is as difficult to rally behind as it is to predict.
In short, the planet is warming, the oceans are rising. By how much and why leaves much room for debate, but it is an issue becoming increasingly impossible for coastal communities to ignore.
"We have begun the conversation about how do we approach this whole topic," Ventura County Supervisor Steve Bennett said. "It's a very complicated moving target to try to map."
Bennett said at least there's been a shift in the mindset of many people who ultimately will make the decisions about how to address climate change.
"The difference is people are not in the denial phase," Bennett said.
In the 20th century, the sea level rose on average 8 inches along California's coastline, research by Climate Central and others shows.
Middle-of-the-road expectations are that it will rise 6 to 8 more inches by 2030, 12 inches by 2050 and 24 inches by 2070.
By 2100, it could be 3 to 5 feet higher, said Gary Griggs, director of the Institute of Marine Sciences at UC Santa Cruz.
California has 3.5 million residents living within 3 feet of sea level, Griggs said. He knows planners might find it difficult to spend a lot of time and energy on planning for a rise in the sea level, "but it would be a mistake to allow uncertainty to get in the way of action or preventive measures that are intended to reduce the potential for future damage or losses," he wrote in "Adapting to Sea Level Rise: A Guide for California's Coastal Communities."
The report, funded by the Public Interest Environmental Research Program of the California Energy Commission, is going to be sent to heads of coastal communities, Griggs said. He noted the first thing they need to do is look at how vulnerable they are and what the highest-risk areas are.
Even small increases in ocean levels add to tide and storm surge. That means there's a much greater chance of more 100-year floods, according to "Surging Seas," a separate report recently released by Climate Central.
The study looked at homes within 3 feet of high tide -- a more accurate predictor of flooding impacts, the report says -- rather than just looking at those above sea level. Using that measure translates into more homes at risk.
"You have to work with the ocean, not against it. ... It's acknowledging that building ever higher and higher walls is not a sustainable way to deal with the forces of nature," Ventura City Manager Rick Cole said.
In Oxnard, Calif.'s Mandalay Bay community, problems between
Research out of the U.S. Department of Defense focusing on five military bases, including Camp Pendleton in San Diego County, aims to develop a methodology that captures how to best evaluate a coast's vulnerability to a rise in the sea level.
"At this point, we're not doing anything except to try to get a better grip of what the problem is and how to address it," said Bob Freeman, spokesman for the Navy Office of the Oceanographer's task force on climate change.
That's more complicated than just considering whether the ocean will reach the steps to a building. Impact on the drinking water supply, infrastructure under a pier and wildlife all must be considered, Freeman said.
The Navy is developing a shoreline protection plan for erosion control at Naval Base Ventura County, Point Mugu in California.
The study will look at ways to protect infrastructure, maintain Beach Road, and preserve existing natural resources and habitats, Gearhart said.
"We're looking at it from a future building standpoint," Gearhart said. "How do we stop the erosion? How do we not build so close to the coast to be affected?"