The evacuation of nearly 200,000 people near Oroville Dam is the kind of event that makes climate change personal. Like many extreme events, the Oroville emergency is a combination of natural weather likely intensified by climate change.
Dams in the United States were built 50 years ago, on average. Since then, the Earth's surface temperature has warmed about 1.35°F, and there's now more than 5% more water vapor in the atmosphere as a result, which intensifies storms. With hotter temperatures, more precipitation falls as rain and less as snow, and California's Sierra snowpack also melts earlier in the year.
Our infrastructure was designed for yesterday's climate, not today's or tomorrow's. We know the climate is changing and we need to be prepared.
We already see fundamental changes in storm frequency and intensity, increases in the size and duration of droughts and rainfall events, disappearing snow packs, growing agricultural water demands with rising temperatures, and more.
We cannot afford the luxury of pretending climate change isn't real, and we cannot afford to ignore the risks to our water infrastructure posed by these changes. Any investment in infrastructure must take climate change into account through smart flexible design, integration of better weather-forecasting and modeling tools, and adoption of new standards for facility construction and operation.
Environmental groups warned the state about Oroville Dam in 2005, noting that in an intensely wet year like we've seen in 2017, its emergency spillway could erode, and thus should be coated with concrete. State agencies concluded that the cost of this project couldn't be justified given the low probability of such a wet season, but climate change increases the likelihood and intensity of extreme precipitation events.