Laying Odds on Climate

Researchers from a broad spectrum of fields presented a vision of California’s future that may be prone to more frequent climate-driven extremes, including heatwaves, coastal erosion and water supply challenges.

The workshop held at Scripps Institution of Oceanography, UC San Diego, Dec. 13 drew more than 250 people who heard several key messages.   While the event, titled “Vulnerability and Adaptation to Extreme Events in California in the Context of a Changing Climate: New Scientific Findings,” celebrated California’s forward thinking on observing and understanding climate change, it called alarm to the potential for a cascade of extreme events in the state that could be exacerbated as global climate changes.  A wide-ranging round-up of findings included:

• Energy consumption could rise by 50 percent by the end of the century as summer heatwaves become more frequent, which in turn would require greater use of air conditioners and refrigeration and further increase electricity demand.
• Agricultural revenues will continue to grow, but more slowly than would be presumed by historical rates.   
• Heat waves, occurring with increasing frequency, intensity, and duration, would provoke greater public health risks with more emergency hospitalizations and a higher threat of mortality, especially within the State’s most vulnerable populations. 
• Generally rising temperatures will have an effect on the three million acres of California orchards that require wintertime chilling.
• By 2050, under middle-of-the-road projections of warming, spring snowpack in the Sierra Nevada would fall to less than 70% of today’s average amounts.

“We are entering – at an astounding rate – a new climate which carries with it a more challenging breed of extreme events that is unfamiliar to expectations from our present experience,” Scripps climate scientist and workshop organizer Dan Cayan told the audience. 

The day-long workshop was a summary of state-of-the-art findings on potential climate impacts on the state and what it will take to prepare for them. Gov. Edmund G. “Jerry” Brown requested the workshop be held as a companion to his own hearing on California’s climate and extreme weather future held Dec. 15 in San Francisco.

Scientists have long expressed climate forecasts in terms of probability. Now, signals are emerging that phenomena are occurring similarly to those that were indicated in these early projections. In the workshop’s opening remarks, Scripps Director Tony Haymet set the tone by noting a recent compilation by NOAA that in 2011 there were 12 U.S. weather events that caused more than a billion dollars each in damage, a new record.

Scientists widely agree that the earth is already committed to a significant amount of climate change especially as greenhouse gases accumulate in the atmosphere. As a result, the global discussion about climate change has increasingly focused on adaptation strategies. Recent gatherings at Scripps have reflected an attitudinal shift that the risks from climate-driven events are serious enough that action must be taken to adapt. Events in the last two years hosted by Scripps have drawn in industries affected by climate change, including the U.S. military, utilities, and business sectors.  

The workshop included talks from social scientists who are investigating motivations of and barriers to municipalities in investing in projects designed to deal with anticipated infrastructure needs. Economists were on hand to discuss how climate change is likely to change electricity demand.

One such researcher was Maximillian Auffhammer, an economist at UC Berkeley, who foresees a future in which peak electricity demand in California will balloon to levels not seen in the state’s recent historical experience. This includes an increased demand for air conditioners in cool coastal areas that traditionally have functioned without air conditioning.  Auffhammer was one of two participants from Tuesday’s workshop invited to report to Gov. Brown’s meeting of state legislators in San Francisco. Afterward, Auffhammer said that the state leaders in the meeting appeared to have moved on from doubting climate change.

“Nobody in the room expressed that,” Auffhammer said. “You had a roomful of stakeholders at the very highest levels. The question wasn’t whether we should prepare but how best we should prepare.”