STUDIES: FIRE TOLL TO GET EVEN WORSE
Warming: Climate change fueling threat; state vows to take action
Heat waves will grow more severe and persistent, shortening the lives of thousands of Californians. Wildfires will burn more of the state’s forests. The ocean will rise higher and faster, exposing California to billions in damage along the coast.
These are some of the threats California will face from climate change in coming decades, according to a new statewide assessment released Monday by the California Natural Resources Agency.
The projections come as Californians contend with destructive wildfires, brutal heat spells and record ocean temperatures that scientists say have the fingerprints of global warming.
“This year has been kind of a harbinger of potential problems to come,” said Daniel Cayan, a climate researcher at the Scripps Institution of Oceanography and one of the scientists coordinating the report. “The number of extremes that we’ve seen is consistent with what model projections are pointing to, and they’re giving us an example of what we need to prepare for.”
State leaders vowed to act on the research, even as the Trump administration moves to unravel climate change regulations and allow more pollution from cars, trucks and coal-fired power plants.
“In California, facts and science still matter,” Gov. Jerry Brown said in a statement. “These findings are profoundly serious and will continue to guide us as we confront the apocalyptic threat of irreversible climate change.”
The state’s assessment draws on the latest science, including more than 40 new peer-reviewed studies, to project the effects of the continued rise in greenhouse gases on California’s weather, water, ecosystems and people
and offer guidance on how officials across the state might adapt.
It’s the fourth such report since 2006, when Gov. Arnold Schwarzenegger ordered a climate change assessment as precursor to the Global Warming Solutions Act, the pioneering law California adopted that year to cut greenhouse gas emissions to 1990 levels.
California has already warmed 1 to 2 degrees since the beginning of the 20th century as a result of the human-caused buildup of greenhouse gases. That figure could rise to between 5.6 degrees and 8.8 degrees by 2100, depending on the amount and rate of pollution spewed into the atmosphere, according to the report.
Those climbing temperatures could cause 6,700 to 11,300 more heat-related deaths annually in California by midcentury, the assessment found. Such fatalities will dominate economic damage to the state from climate change, costing up to $50 billion a year by midcentury.
Scientists have long projected more intense and longer-lasting heat waves by midcentury but have observed those changes occurring faster than anticipated.
“Something that used to happen every 10 years is happening every year,” said Rupa Basu, chief of air and epidemiology for the state’s Office of Environmental Health Hazard Assessment.
Adding to the risks, scientists say, are trends toward higher humidity and warmer nights. Such conditions hinder people’s ability to recuperate and raise the likelihood of hospital and emergency room visits for a variety of illnesses, from heatstroke and dehydration to heart attacks, kidney disease, gastrointestinal illness and preterm births.
More air conditioning could attenuate some of the harm, at least for those who can afford it.
As the ocean continues to warm, California’s coast will face more beach erosion, flooding and storm damage.
Until recently, scientists and state policymakers worked with a projection that sea level rise by the end of this century could amount to about 5.48 feet in California under the worst case scenario. But the latest reports and state policies are now accounting for the extreme possibility that sea level rise could exceed 9 feet.
These broader projections incorporate the potential rapid melting of the West Antarctic ice sheet.
Even if the sea rose 6.56 feet rather than the higher possible extreme now adopted by the state, more than 250,000 residents, $38 billion in property and 1,400 miles of roads along the coast are at risk of flooding during a severe storm in Southern California, according to a study led by the U.S. Geological Survey.
One such response is the creation of natural shoreline infrastructure, such as vegetated dunes, native oyster reefs or seagrass beds that help buffer wave action and hold back the encroaching sea, according to a report led by the Nature Conservancy.
Northern California — the source of much of the state’s water supply — is likely to grow a bit wetter with climate change. But global warming will alter the timing and form of precipitation, making it tougher for the state to hold on to it.
As rising temperatures drive more wildfire in California, the greatest increase is expected in the forests of the Sierra Nevada and southern Cascade mountain ranges.
Forest area burned every year could more than double by the end of the century, according to research by UC Merced professor Anthony Westerling.
Rising temperatures will increase demand for electricity across the state as more people install and use air conditioners — even in coastal areas where people have traditionally gone without them.
“If San Francisco with its pleasant coastal climate gets Fresno’s hot climate by end of century, even cool San Franciscans will install window units in existing apartments and new construction will be built with central air conditioning,” according to one study included in the state’s climate assessment.
UC Berkeley environmental economics professor Max Auffhammer, who authored the study that analyzed utility bills for households across the state, found a silver lining: Increased electricity demand will be more than offset by reductions in natural gas use for heating as a result of milder winters.
“Electricity consumption is going to go up in the summer,” he said. “But it looks like climate change is going to save many California consumers a bunch of money on their heating bills in the winter.”