California power giant PG&E may shut off electricity in parts of roughly 30 counties to stem risks of downed power lines sparking wildfires when strong and dry winds arrive later this week.

Why it matters: The plan announced Monday, which the San Francisco Chronicle called "unprecedented," highlights how utilities are grappling with dangers heightened by global warming.

Climate change and the hotter and drier conditions it brings are among the forces that increase fire risks and severity.

The big picture: The utility's announcement comes as a new report Tuesday shows how California's fatal and devastating wildfires in 2018, in addition to their human toll, were a major source of carbon emissions as they burned nearly 2 million acres.

Threat level: Wildfires are another reason why California will be hard-pressed to meet requirements in state law to cut greenhouse gas emissions by 40% below 1990s levels by 2030, the report finds.

"As the wildfire seasons grow longer and our lands grow dryer, managing this threat will be critical to our climate success," states the report from the nonprofit group Next 10 and the firm Beacon Economics.

What they found: Last year's fires were a larger emissions source than 2017 levels from the state's commercial, residential or agricultural sectors, as the chart above shows.

The important numbers: "California has achieved consistent emissions reductions annually for the past several years, reducing emissions by 1.15 percent economy-wide in 2017," the annual report on California's emissions states.

"But these achievements were eclipsed several times over by the 2018 wildfires, which produced more than nine times more emissions than were reduced in 2017," it adds.

Where it stands: The bankrupt utility said the plan could affect more than 600,000 customers.

"This is shaping up to be one of the most severe dry wind events we’ve seen in our territory in recent years, and we want our customers to be prepared for an extended outage that may last several days," said Michael Lewis, PG&E's senior VP for electric operations, in a statement.

What's next: Some outages appear inevitable.

"The utility confirmed Monday afternoon that it plans to begin shutting off power in Napa County beginning early Wednesday morning due to a 'potentially widespread, strong and dry wind event' that is forecast through Thursday afternoon," CBS News reports.

Go deeper: Humans are a wildfire threat multiplier