SAN DIEGO — All evacuation orders were lifted Sunday as firefighters gained the upper hand on the remaining four of nearly a dozen blazes that tore through Southern California last week, but Governor Jerry Brown cautioned that he was gearing up for what could be the worst wildfire season ever.
Brown said on ABC’s ‘‘This Week’’ that the state has 5,000 firefighters and has appropriated $600 million to battling blazes, but that may not be enough.
‘‘We’re getting ready for the worst,’’ he said. ‘‘Now, we don’t want to anticipate before we know, but we need a full complement of firefighting capacity.’’
The state firefighting agency went to peak staffing in the first week of April instead of its usual start in mid-May.
Thousands of additional firefighters may be needed in the future, Brown said, adding that California is on the ‘‘front lines’’ of climate change that is making its weather hotter.
Ocean breezes and lower temperatures over the weekend made it possible for firefighters to control the remaining fires. They included a 4-square-mile blaze that started in the suburb of San Marcos and three brush fires at Camp Pendleton.
Unusually high temperatures, low humidity, and gusty winds set conditions last week for the string of wildfires that broke out in San Diego County, causing more than $20 million in damage.
The California Department of Forestry and Fire Protection has responded to more than 1,500 fires this year, compared with about 800 during an average year.
The fires spanning 39 square miles chewed a destructive path through San Diego County, destroying at least 47 houses, an 18-unit apartment complex, and three businesses. A badly burned body was found in a transient camp, and one firefighter suffered heat exhaustion.
Most homes were destroyed in two suburbs about 30 miles north of San Diego: San Marcos, an inland commuter city of new housing tracts; and Carlsbad, a coastal community and home of Legoland California.
The first blaze started Tuesday and was caused by a spark from construction equipment, according to state officials. It could take months to get to the bottom of the most damaging fires.
The recent wildfires in Southern California offer a glimpse of a more fiery future, according to scientists and federal and international reports. In the past three months, at least three studies have warned that wildfires are getting bigger and that manmade climate change is to blame.
‘‘The fires in California and here in Arizona are a clear example of what happens as the Earth warms, particularly as the West warms, and the warming caused by humans is making fire season longer and longer with each decade,’’ said University of Arizona geoscientist Jonathan Overpeck.
Since 1984, the area burned by the West’s largest wildfires — those of more than 1,000 acres — have increased by about 87,700 acres a year, according to an April study in the journal Geophysical Research Letters. And the areas where fire has been increasing the most are where drought has been worsening and ‘‘that certainly points to climate being a major contributor,’’ said the study’s main author, Philip Dennison of the University of Utah.
Likewise, the Nobel prize winning Intergovernmental Panel on Climate Change noted in March that wildfires are on the rise in the western United States, have killed 103 Americans in 30 years, and will most likely get worse.
The immediate cause of the fires can be anything from lightning to arson, but they are fueled by drought, heat, and winds.