What do cows in Chino and the Porter Ranch-area gas leak have in common?

If anyone thought the Porter Ranch-area gas leak was the only major contributor of methane to Southe Califoia’s air, think again, according to a new study.

The findings, by UC Irvine atmospheric scientists, show hundreds of “methane-emitting hot spots” across the Los Angeles region.

They include:

• a “clean ports” truck refueling facility near the Port of Long Beach

• power plants

• water treatment facilities

• cattle in Chino

Why should anyone care?

Methane, the gas that until last Thursday had been leaking in massive amounts from a now-sealed well above Porter Ranch in the northe San Feando Valley, is the second-largest known contributor to global climate change.

Carbon dioxide is the top contributor, according to the scientists.

And in 213 hot spots, that methane is creating an “ever-present dome of methane that hovers over the region,” according to a UC Irvine report on the findings.

For this study, the scientists conducted a mobile survey across Los Angeles, Orange and Riverside counties.

Their results were published this week in the Joual of Geophysical Research: Atmospheres.

The study was done before the Porter Ranch-area leak at Southe Califoia Gas Company’s Aliso Canyon storage facility was discovered on Oct. 23.

But it’s no less important, according to scientists.

“The findings could be used by the Gas Co. to meet orders by Gov. Jerry Brown and the state Air Resources Board to offset the gas leak by removing as much of the fast-acting greenhouse gas from the air as was emitted from the Aliso Canyon site,” according to a UC Irvine publication on the hot spots.

- - , .