Craig Miller

The new normal? A temperature display in the Kern County town of Taft shows 105 degrees on a late afternoon in July.

Granted, it’s been a relatively cool summer in many parts of California. But state officials are saying, “Don’t get used to it.” How would you like to see the number of “extremely hot” days (105 or hotter) in Sacramento increase fivefold in the next few decades? That’s just one of many new projections from the state’s latest official climate assessment.

One hundred-twenty scientists worked on the report, entitled California’s Changing Climate (PDF). Funded by the California Energy Commission, it’s actually a portfolio of studies and contains some of the most specific warnings we’ve seen. For instance, it projects that going forward, average temperatures in the state will warm at three times last century’s pace. It’ll mean heat waves happening more often and lasting longer.

And there’s new evidence from a refined set of models that the state will be drying out. “By mid-century, already we’re seeing a drying trend which could be up to ten percent drier by the end of the century, says Susanne Moser, identified as the principal researcher for the report, “and that is significant for a lot of people.” Especially if you live in say, the San Joaquin Valley, where the report projects that the frequency of “dry years” could increase by about a third in the “latter half of this century,” compared to the late 20th century.

And authors expect the weird weather to get worse, projecting that as soon as 2050, what’s now considered a 100-year storm could become ‘an annual event.”

State officials nearly fell over each other to say that it’s not too late to blunt some of the worst effects, however, with astute planning and aggressive action to reduce global warming emissions. Ken Alex, who heads Governor Jerry Brown’s Office of Planning & Research, characterized the mounting climate threats as, “a series of plagues,” but added that, “we’re not helpless. We need to adapt and we need to understand what that adaptation requires.”

Some interesting numbers from the study:

• 1.7: increase in statewide average temp from 1895 to 2011, in degrees Fahrenheit
• 2.7: likely increase by 2050, compared to 2000
• 20: Number of days per year that the temp could reach 105 in Sacramento by 2050 (versus four, historically)
• 10-18: Likely range of additional sea rise along California by 2050 (v. 2000)
• 23: Number of San Francisco fire stations that would likely be inaccessible with 16 inches of additional sea rise (considered likely by 2050)

CA Climate Change Center

Scientists say how much temperatures eventually rise will depend on the pace of continued global warming emissions.

The study suggests that temperatures will rise more in the summer and inland, with springtime warming “particularly pronounced” and fewer cold nights. Farmers depend on chilly nights to produce some high-value crops, such as stone fruits. Officials at the Energy Commission expressed concern about potential impacts that rising temperatures will have on the state’s power grid, some of which we addressed in a previous post.

As for reducing emissions enough to make a tangible difference, Moser concedes that’s not a job that California can do alone. But she said this report is the first to target findings to the kinds of questions that officials and planners have been asking (like the aforementioned matter of how many triple-digit days they can expect–and how soon).

Using IPCC climate projections, the study models how climate change will impact California up and down the coast, including coastal cities like San Francisco and inland cities such as Riverside and Fresno.

Lead author Scott Sheridan, a geographer at Kent State University, says that the projected increase in heat-related deaths among those 65 and over are due in part to physiological reasons, but also to growing population size of this age group. By the end of the century, he says, the state’s population of people in this age bracket will increase from 4 million to 15.7 million. Sheridan says California communities that are already used to dealing with hotter temperatures, like the inland city of Fresno, may be better prepared to deal with the heat than relatively cooler coastal cities.

“On a hot 90-degree day in Riverside, everyone has the AC running. In San Francisco, not everyone has that luxury.” says Sheridan.

Sheridan says that heat-related deaths are projected to go up more in coastal cities like San Diego than in inland cities because people on the coast may be less acclimatized to extreme heat and the cities themselves may lack the preparation to deal with the public health consequences of lengthy, intense heat waves.

Projected heat-related deaths based on various climate change scenarios in San Diego. The red line indicates a high fossil fuel intensive scenario. Chart: CARB/EPA

“People that are acclimatized to warmer temperatures have a greater threshold for heat.” says Sheridan.

CARB spokesperson Dimitri Stanich says the study could lead to more local health policies in cities that are more vulnerable.

“Previously studies have focused on a macro approach to heat impacts but couldn’t specify impacts on California cities.” says Stanich.

Sheridan says one potential model for California cities is Philadelphia.  The health department there helped residents get fans, and it developed a buddy system to for neighbors to keep in touch during hot days. Philadelphia also has 60 cooling stations running during the summer, which can be found using this interactive map developed by the city’s Office of Emergency Management.

To see how temperatures are expected change in your region of California, check out the interactive Cal-Adapt tool from the California Energy Commission.

Flooding along San Francisco's Embarcadero during an extreme high tide in February. (Photo: Heidi Nutters/Flickr)

Even if the world stopped emitting all greenhouse gases today, scientists say, the climate would continue to change, perhaps for centuries, before it stabilized.  Since a zero-emissions world is unlikely, to say the least, and considering that global carbon emissions are continuing on their upward trend, finding ways to adapt to what many see as inevitable is getting more and more attention.

The San Francisco Planning and Urban Research Association (SPUR), a local think tank focused on sustainable growth, has just released a 40-page report that outlines the Bay Area’s biggest climate risks and lays out a road map for how communities can start preparing.

The upshot?  We’ve got a lot of work to do.

“We need to beginning planning on many fronts because climate change is going to affect the way we do business. It’s going to affect everything from people’s health to property values on the shoreline,” said SPUR’s Laura Tam.

The report finds that the climate change impacts most threatening to the Bay Area are more intense heat waves, water uncertainty (droughts, wildfires, extreme storms and flooding), and sea level rise. It lays out step-by-step instructions for addressing these risks, in terms of public safety and health, water supply, transportation infrastructure, biodiversity, and the region’s energy supply.

Heat waves are a big focus of the report, which, if you live in San Francisco like me, may seem improbable.  Yet, Tam says it’s exactly places like San Francisco that are most vulnerable to increased heat waves because we’re not prepared for them.  (How many people here do you know with air conditioning?)

The report says that by 2100, the Bay Area may experience between 74 and 90 days above 81 degrees Fahrenheit per year.  Throughout the 20th century, the Bay Area averaged about 12.  An increase like that means greater risk for heat-related illnesses and some infectious diseases, as well as poorer air quality.  To address this, SPUR recommends communities identify vulnerable populations, reduce the “urban heat island effect” by promoting white roofs and urban forestry, build communications and public warning systems, and develop robust “heat response plans” and air quality monitoring programs.

Will Travis, the executive director of the San Francisco Bay Conservation and Development Commission (BCDC) and a SPUR board member, said that cash-strapped cities and towns have been “reticent” to deal with climate change adaptation because it can seem like a problem of the future.  But, communities are going to have to act soon to avoid a crisis that’s both environmental and economic, he said.

“Our region is not going to be able to remain competitive and attract the capital we need to make our innovative economy grow if we don’t address this problem right now,” said Travis.

According to BCDC, the Bay Area may see 55 inches of sea level rise by 2100. The SPUR report says that means more than 186 miles of major roads (including I-80, I-880, U.S. 101, Highway 37, I-680, and Highway 12), more than 105 miles of regional rail track, and 93% of Oakland Airport and SFO property will be vulnerable to flooding.

“That transportation infrastructure is the lifeblood of what makes our economy work,” said Travis. “We need that mobility, so we’re going to have to be retrofitting those facilities to make sure that they don’t go underwater.”

The report recommends agencies conduct a comprehensive transportation vulnerability assessment, design resilient new transportation projects, and develop emergency transportation alternatives for cases of extreme weather events.

The report is dense and detailed, and it’s a sobering look at exactly how much needs to be done to prepare for what many state and regional agencies agree is likely on its way. Odds are, none of this will be cheap. And yet, according to SPUR’s Laura Tam, beginning to deal with climate change impacts now could save money as well as lives.

“If we don’t start planning ahead and preparing, we will end up dealing with crises that emerge as emergencies, and we don’t want to be in the position of having to respond to climate emergencies,” she said.  “We want to know what to expect, and be prepared, so that the least amount of property is damaged and the least amount of people suffer.”