Nov 8 (Reuters) - California regulators voted on Friday

to toughen a policy aimed at boosting low-carbon fuels to slash

greenhouse gas emissions from the transportation sector and meet

state climate change goals, despite criticism it would increase

retail fuel prices.

The 14-member California Air Resources Board voted 12 to 2

to approve changes to the state's influential Low Carbon Fuel

Standard (LCFS). The vote followed nearly eight hours of

testimony from supporters and opponents of the program, as well

as a lengthy debate among board members.

Several members said the changes were essential to

preserving Democrat-led California's climate leadership

following Donald Trump's presidential victory. Trump, a

Republican, has pledged to rescind California's ability to set

its own vehicle emission rules, as he did during his first term

as U.S. president.

"The world is watching California to see if we will maintain

leadership or fracture under internal pressure for

perfectionism," state Senator Henry Stern, a non-voting board

member, said in a statement read at the meeting by fellow board

member Hector De La Torre.

"California has a long history of enacting visionary and

affordable climate policies that are durable enough to endure

major shifts in national politics like we just witnessed."

The amendments to the LCFS, which has been in place since

2011, would require a deeper reduction in the carbon intensity

of transportation fuels by 2030 in order for fuel producers to

earn the program's tradable credits.

Transportation accounts for about 50% of the state's

greenhouse gas emissions.

While biofuel producers and some state climate advocates

backed the changes, critics including oil companies and consumer

advocates said the change would increase gasoline costs for

Californians. Environmental groups also argued that the policy

would extend the production of oil and gas and prioritize fuels

made from food crops and large dairy operations instead of

encouraging a transition to electric vehicles.

The LCFS requires fuel makers to buy tradable credits if

their products generate more carbon emissions than a baseline

set by regulators at the air resources board. Refiners that

produce low-carbon fuels and gases can generate the credits to

sell.

The policy set off a boom in renewable diesel and biogas

production in recent years that has sent credit prices down to

around $70 from above $200 in 2020. The policy revisions are

meant to prop up credit prices and encourage more low-carbon

fuel production.

As a result of the board's vote, the LCFS will require a 30%

reduction in the carbon intensity of transportation fuels by

2030, up from 20%. The revisions will add a 90% carbon intensity

reduction goal by 2045.

Developers of projects that produce renewable fuels from

organic waste supported the measures.

Opponents voiced concern, however, about the potential for

higher gasoline prices.

In an analysis released last year, the board said the

changes could increase the price of gasoline by 37 cents a

gallon, on average, from 2024 through 2030. But the board has

since said models cannot accurately predict future fuel prices.

The board's internal environmental justice advisory

committee had urged it to reject the revisions, citing an

exemption for jet fuel producers and large subsidies for dairy

methane projects, among other concerns.