California billionaire Tom Steyer, recently profiled in The Times as the emerging liberal counterweight to the Koch brothers, is doubling down.

The financier is planning to spend at least $100 million on tough attack ads targeted at congressional and gubernatorial candidates in the 2014 election cycle who oppose efforts to curb global warming, according to a report in the New York Times. Steyer will contribute $50 million himself and is seeking to raise the rest from other wealthy donors, the report said.

The funds would be spent through Steyer’s San Francisco-based political organization, NextGen Climate Action. An aide to Steyer confirmed such spending is planned.

It comes after Steyer has already spent $50 million on elections over the last couple of years. The money went to help pass a California ballot measure that will boost spending on energy efficiency programs by $500 million a year, to help elect Democrat Terry McAuliffe governor of Virginia, and to help elect Edward Markey to the U.S. Senate.

This latest infusion of spending would not go exclusively to attacking Republicans. In fact, Democrats with close ties to the oil and gas industry could find themselves in the crosshairs of the campaign. Steyer has said repeatedly that he believes climate change is the most important issue confronting the country, and he has structured his political apparatus around pressuring lawmakers to confront it.

The former hedge fund manager has many deep-pocketed friends, and is among President Obama’s top fundraisers. He is seeking to harness growing frustration among many Silicon Valley donors about the lack of action on global warming. Silicon Valley’s interest in the issue is not just philosophical. It is also financial. Many of the area’s venture capitalists are heavily invested in the renewable-energy sector.

A look at Steyer’s calendar for the week makes clear his clout.

On Wednesday, a number of senators will be at his San Francisco home for a fundraiser he is co-hosting for the Democratic Senatorial Campaign Committee. He’ll be showing them polling data that make the case that any support they may give to the planned Keystone XL pipeline – which would ship vast amounts of oil from the Canadian tar sands to Gulf Coast refineries – will come at their peril.

Later in the week, at the Democratic Governors Assn. meeting in Washington, he’ll be running the panel on what governors can do to address climate change while Congress dithers.

The latest NextGen Climate Action campaign, according to one person involved, will specifically target for defeat candidates who are climate change skeptics. The organization will also be looking to support gubernatorial candidates seeking to take the kind of action on global warming that states like California have in the absence of congressional action.

evan.halper@latimes.com

Twitter: @evanhalper