Center for Biological Diversity

For Immediate Release, September 21, 2016

Contact: Patrick Sullivan, (415) 517-9364,                 

Analysis: Monterey County Crude Worse for Climate Than Alberta Tar Sands Oil

San Ardo Is California's Most Carbon-intensive Big Oilfield

SAN ARDO, Calif.— Crude from Monterey County's biggest oilfield is more climate damaging than any other large source of oil produced in, or imported into, California, according to a new Center for Biological Diversity analysis of state data. The Center’s report, titled Stealing California's Future, found that crude from the San Ardo oilfield is even more carbon-intensive than notoriously dirty oil from the Alberta tar sands in Canada.

Stealing California's Future

Today's report also found that the San Ardo field is the most carbon-intensive large oilfield in California, ultimately generating about 3.3 million metric tons of greenhouse gas pollution a year — equivalent to driving a car 8 billion miles. Carbon intensity is one measure of the planet-warming pollution associated with crude production, from the well to the refinery. Yet the Center's report notes that state and federal regulators are poised to lay the groundwork for an expansion of the San Ardo field.

“The dangerously dirty oil spewing out of San Ardo’s wells is a major threat to California’s fight against the climate crisis,” said report author Brian Nowicki, the Center's California climate policy director. “As we struggle to fend off the worst effects of climate change, regulators should not worsen warming by letting oil companies produce even more high-carbon crude from this incredibly polluting field.”

With more than 1,000 active wells, San Ardo already produces more than 7.6 million barrels of oil a year — almost 4 percent of the state's annual production. The oil industry is currently pursuing “aquifer exemptions” from the federal Safe Drinking Water Act that would allow companies to continue to dump oil-waste fluid into groundwater around San Ardo. If approved by the U.S. Environmental Protection Agency, these exemptions would pave the way for expanded drilling and oil production.

San Ardo’s heavy crude is so thick that oil companies typically use extreme extraction techniques like cyclic steaming — which require enormous amounts of water and energy — to extract it. In 2015 oil companies used almost 2 billion gallons of water in cyclic-steam and steam-flood operations at San Ardo. The energy required to heat that vast volume of water is one key reason why this oilfield is so bad for the climate.


Crude Origin

Crude Type

Carbon Intensity*


Monterey County

San Ardo



Alberta, Canada

Suncor Synthetic (all grades) (tar sands oil)



Alberta, Canada

Albian Heavy Synthetic (tar sands oil)



Alberta, Canada

Cold Lake (tar sands oil)











* Carbon intensities in gCO2e/MJ; volumes in barrels per year. Source: Air Resources Board.

“California just suffered the hottest summer in recorded history, so it's crucial for Gov. Jerry Brown’s oil regulators to quickly cut climate pollution from dirty oilfields like San Ardo,” Nowicki said. “Doubling down on production of this climate-damaging oil would directly undermine our state’s crucial efforts to avert the worst risks of global warming.”

Download Stealing California's Future: How Monterey County's Dirty Oil Business Worsens the Climate Crisis.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.1 million members and online activists dedicated to the protection of endangered species and wild places.

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