FRESNO (AP) — As California grows warmer, nowhere will the increased temperatures be starker than its arid Central Valley, where farmers will have to consider whether the crops grown today will survive in a harsher environment.
Rising sea levels will also flood coastal airports and municipal sewage systems, while earlier springs will hasten snow melt and reduce the state's capacity to generate hydroelectric power in the summer months when it's needed most.
A report released Tuesday by the state is an attempt to study where California is most vulnerable to the impacts of climate change so future planning decisions can take the conclusions into consideration.
"We accept that cigarette smoking causes cancer and that HIV causes AIDS, and as a state we make decisions based on those scientific considerations," said Ken Alex, senior policy adviser to Gov. Jerry Brown, "We are not in the same place with climate change."
It's a follow-up to a 2009 report that said climate change already is happening across the state. This report is designed to tell citizens what that change might mean to them, said Susanne C. Moser, one of 120 scientists who contributed.
"If we assume a particular scenario of greenhouse gas emissions, how likely will a certain amount of sea level rise occur? How likely is it that we will still see freezing temperatures in the future?" Moser said, explaining the report's objectives.
The report says that temperatures statewide are up 1.7 degrees since 1895. By 2050 California is expected to be 2.7-degrees warmer than it was in 2000.
A warmer climate means fewer nights below freezing, which farmers in the San Joaquin Valley would want to consider when planting or replacing fruit trees that depend on chill hours, the report said.
Planners also must consider that more of the state's precipitation will fall as rain rather than snow in a state where water delivery and storage counts on snow melt to steadily supply it through the summer dry season.
"Central and southern parts of the state can be expected to be drier from the warming effects alone as the spring snowpack will melt sooner and the moisture contained in soils will evaporate during the long dry summer months," the report said.
Because of poverty and a lack of transportation, Los Angeles will have the most vulnerable people during extreme heat.
San Francisco and other coastal areas will be most impacted by rising sea levels. If development continues at the current rate, by 2100 a 55-inch rise in sea level will put 480,000 people and $100 billion of property at risk, the report said. Sea levels have risen about seven inches over the past century.
"People cause disasters by virtue of how we build things, where we locate them and our ongoing day-to-day decisions that actually determine what's lost when nature's extremes occur," said Dennis Mileti, former co-director Natural Hazards Center at the University of Colorado, Boulder. "What they're saying is it's going to get worse."
The report suggests that vulnerable ports alter infrastructure to prepare for the future but acknowledges the cost could be prohibitive. It says that officials should consider making changes during scheduled upgrades.
Hotter temperatures already are leading to more and larger fires, and the number could grow as much as 128 percent above normal by 2085, the report said. Of the 20 largest fires recorded in California, 11 have come since 2002. Until then, the state averaged one large fire per decade.
Officials hope citizens will understand steps they can take to protect themselves, such as clearing brush from their property, in an environment growing increasingly more dangerous.
The increased intensity of wildfires also means that high-power transmission corridors that cross the state leave power supplies vulnerable to disruption, even as higher temperatures make the transfer of energy less efficient. The report says building local power generation stations and micro-grids will be essential.
"The electric system is much more vulnerable than we thought," said Bob Weisenmiller, chairman of the California Energy Commission.