Panel discussion: The impacts of climate change on water resources

Peter Gleick, Noah Diffenbaugh, Wade Crowfoot, and Solomon Hsiang discuss the current drought and climate change, focusing on water resources, climate risks, economic impacts, and policy solutions

The Hamilton Project at Brookings and the Stanford Woods Institute for the Environment hosted the forum, New Directions for U.S. Water Policy, in October of last year, which focused on the release of three new papers and featured panels discussing water markets, innovation, and climate change.

In this panel discussion moderated by Thomas Steyer, Noah Diffenbaugh, the associate professor of Environmental Earth Science System at the Stanford Woods Institute for the Environment; Peter Gleick, president and co-founder of The Pacific Institute; Wade Crowfoot, Deputy Cabinet Secretary and Senior Advisor for Governor Jerry Brown; and Sol Hsiang, the assistant professor of Public Policy at The Goldman School of Public Policy at the University of California Berkeley.

Before that Mr. Rubin began by noting that his sole function is to introduce the moderator and facilitator of the panel, Tom Steyer. He mentioned that he has known with Tom Steyer for more than 25 years. “One day Tom said to me that he had reached a conclusion that climate change was the issue of our age and that he was going to work to change the conversation about climate change to create a sense of commitment and urgency to act,” he said, noting that for the past few years, Mr. Steyer has devoted himself to being one of America’s leaders with respect to climate change policy and advocacy, urging us to act now.

“Because of what Tom said to me, over time, I reached the conclusion that climate change and addressing climate change is really the existential issue of our age and that if we don’t address climate change it will severely affect, and ultimately perhaps catastrophically affect life on earth as we know it,” said Mr. Rubin.

Mr. Rubin then turned the floor over to the panel. “We’re looking at water policy today in the context of a time when the world is undergoing climate change,” began Thomas Steyer. “In particular, we’re all sitting in the middle of California and we’re undergoing a historic drought. We’ve always had droughts and wildfires in the state of California, but right now 100 percent of California is experiencing ‘severe drought.’ 2013 was the driest year in California’s 119-year recorded history and the latest 12 months are the driest on record as well.”

Mr. Steyer acknowledged he was not sure how much of the drought is just cyclical as we’ve had drought before. “We have a group of experts here to talk about the interaction of what naturally occurs and what’s happening in this specific time as a result of changing climate,” he said. “We’re talking about water policy and we’re talking about it in a place that is in crisis, and we can use California as an example of understanding the crisis itself — talking about the impacts, and then talking about what the right policies are going forward.”

Mr. Steyer said there would be three parts to the discussion: First, scientists will discuss how much the current drought relates to climate change and how much is just normal cyclical droughts common to California; then they would discuss the impact on Californians and how it is manifesting itself in the state; and then they will try and focus on policy solutions.

He first turned to Peter Gleick and asked him what the broad impacts of climate change on our water systems in California, and how are the two systems linked. What is the latest data telling us?

“I’m going to try and do four quick things to frame this,” began Peter Gleick. “The first is to say that the climate is changing. We know that the climate is changing because of human activities. We know that. There’s a long history of the science of this.”

“The second point is that among the worst impacts of climate change are going to be on water resources,” he said. “The hydrologic cycle is the climate cycle. As we change the climate, we’re going to affect water, and not just the natural system but the infrastructure and the massive institutions that we put in place to manage water as well.”

“The third is the impacts of climate change on water systems shine a spotlight on the false dichotomy between mitigation and adaptation on climate,” he said. “Maybe if we had had this level of conversation 30 or 40 years ago we could have really focused on mitigation, but the truth is that ship has sailed and we’re now in a world in which we have to mitigate by reducing greenhouse gas emissions, but we have no choice but to deal with unavoidable impacts of climate change on our water systems, and many other things as well. So set aside that dichotomy. You may prefer mitigation. You may prefer adaptation. But we have to do both.”

“The fourth is what do we do about it on the technology side? On the economic side? On the policy side? On the communication side?” Mr. Gleick said. “All of this is wrapped up. The impacts of climate change on water is a big topic because water is connected to everything we care about. It’s connected to energy and human health and ecosystems and our economy and food and agriculture. And as the climate changes, it’s going to affect all of the pieces of that.”

“Temperatures are going up,” he continued. “It’s not only the driest year on record, 2013. In fact, the last 36 months, from October 1 going back 36 months in California have been the 36 driest months on record in California, and the 36 hottest months in California’s 120 years of recorded instrumental record. It’s not only been dry; it’s been hot. And that’s part of the debate here. As temperature goes up, the demand for water goes up. It takes more water to do the things that we want. If you want to grow a green lawn, it’s going to take more water under a hotter climate. So temperature alone is important.”

“Precipitation is going to change, but precipitation is a little tougher,” he said. “The models are a little bit ambiguous about California because we’re in a geographically kind of a strange place. Our water comes in big events off the Pacific. We have to understand storm patterns and so on. It’s complicated. But we do know that the science suggests we’re going to get more extreme events on both ends of the tail of the spectrum, wet and dry. We do know with much less uncertainty about precipitation. Uncertainty to a scientist means there’s a range of outcomes. Uncertainty to the public means you guys don’t know what you’re talking about.”

“We do know with very little uncertainty that we’re going to lose snow pack in California,” Mr. Gleick said, noting that this was the topic of his dissertation 30 years ago. “It gets hotter. The snowline moves up. We’re going to lose snow pack. It may rain the same amount; it may precipitate the same amount, but we’re going to get more rain, less snow. What falls as snow is going to melt faster and runoff earlier, and we already see changes in the timing of runoff in California.”

Sea level rise is going to affect all sorts of things we don’t think about, Mr. Gleick pointed out. “There are 22 wastewater treatment plants in the Bay Area alone at risk of a one-meter sea level rise, which is well within what we expect over the coming decades,” he said. “Coastal aquifers will be affected by sea level rise. Ecosystems. Systems operations. How we choose to operate the dams and reservoirs that we’ve built will be affected by climate change, by sea level rise, by changes in the timing of runoff. So it’s not just the hydrology; it’s the systems as well.”

“The final point I want to make is that despite the fact that we’ve been talking about this stuff for a long time,” said Mr. Gleick. “Our water managers are still not sure what to do about this. They’re not sure how to integrate the coming changes that we now are pretty confident about into management. And in the broader discussion about all of the difficult things that we talk about — water rights, water laws, institutions, the pricing – we now have this additional complication that the climate is no longer static.”

Mr. Steyer then turned to Noah Diffenbaugh, and asked him to discuss how he sees the connection between the drought and climate change. “Why don’t you explain a little bit about how the current drought is affected by climate change and what we can expect going forward in terms of as the climate changes,” said Mr. Steyer. “What is that going to mean for us in terms of water?”

“This is really a question about risk,” responded Noah Diffenbaugh. “One of the big messages coming out of the IPCC reports that have been released over the last year is that it’s really about the risk – the probability of a physical hazard such as a heatwave, a drought or a severe storm and how that interactions with ecosystems, how it interacts with people, and the exposure and vulnerability of different systems.”

“I think the current drought in California is a great example of climate risk,” he said. “We know that it’s a rare event. We know it’s rare in terms of how extremely low the precipitation has been. We understand really well the atmospheric causes, why it hasn’t been raining. This Ridiculously Resilient Ridge as my grad student Daniel Swain has coined the phrase for this atmospheric feature over the Pacific – you can think about it as a ridge of high pressure. It’s basically a boulder that’s been plopped into a stream and the storms that normally would come to California have been diverted pole ward towards Canada and Alaska. And it’s just sort of been parked there for a long time.”

“Really, the question is about risk, and part of the question is how rare are these atmospheric conditions,” he said. “In our recent paper, we’ve concluded that the global warming has very likely increased the probability of those atmospheric conditions by about a factor of three. So it’s still rare, but from the perspective of risk, if we say we’ve having the most severe drought in terms of low precipitation and impact, and it’s three times more likely because of global warming. … It is saying that we’re experiencing increased risk of this kind of event.”

Mr. Diffenbaugh said that they have been doing some research which hasn’t been published yet on temperature. “We know that when it’s warm, snow melts earlier, more precipitation comes as rain rather than snow; we know that soils dry out faster when it’s hotter,” he said. “We’ve been looking back at new data that have been released by the National Climate Data Center, and we now have access to observations going back 120 years of temperature and precipitation and drought.”

“We’ve been looking back at the frequency of low precipitation in California and the frequency of warm temperatures, and I was surprised to find that back in the early and mid 20th century, temperature and precipitation were pretty uncoupled, as we say scientifically,” he said. “It was like flipping two coins separately. We had about 50 percent chance of getting a warm year, and 50 percent chance of getting a cool year. We had about 50 percent chance of getting a wet year, and 50 percent chance of getting a dry year. They were pretty independent.”

The Ridiculously Resilient Ridge in February of 2015

We know with high confidence that California has been getting warmer because of global warming, he said. “This has really changed the probability of the state being warm or even hot when we have the bad luck of it being dry,” he said. “We know that looking back at these long records that are warm and drier; it’s much more likely to produce a severe drought. In fact, it’s about twice as likely when we look back at the whole 120 year record.”

“What has happened is that even though precipitation is noisy and even though climate models have some uncertainty about precipitation, we know with very high confidence that when we get low precipitation in California, we’re about twice as likely to have a severe drought if it’s also warm when the precipitation is low,” Mr. Diffenbaugh said. “We know that over the last 20 years that global warming has substantially increased the probability of years being warm, and now we’re at the point where we essentially have 100 percent chance of having a warm or even hot year in California.”

“It’s going to sound hyperbolic, but we’re essentially approaching 100 percent risk of kind of drought-inducing conditions because of this increase in temperature,” he said.

Mr. Steyer then turned to Sol Hsaing and asked him about what is at risk in terms of the economy. “What are the things we’re trying to protect?,” he asked. “We have fires. People mentioned the ski industry. The agriculture is 80 percent of our water use. When you think about the risks to the economy, the risks to the people of California, how do you categorize what we should be worried about?”

“The way to think about the economic risk of climate change and the drought is to think about how it projects onto the economy,” said Mr. Hsiang. “The economy is made out of a bunch of building blocks — people, crops, buildings and infrastructure — and the drought and climate change affects the productivity of those individual building blocks.”

“When you turn the lever on the productivity of every little person working or every field in the economy, it aggregates up to have really large economic effects nationally,” he said. “In some very new work that we’re just completing, we’re actually seeing, for that on very hot days, counties lose basically $20 per person. Now, if you add that up over 300 million Americans across many days in a year, and in the Risky Business report that we did, we saw that in the future, the number of these extreme events is going to go up dramatically -20, 30, 50 of these a year in some locations. These aggregate up to be very large economics costs.”

Mr. Hsaing said that agriculture is one of the most vulnerable sectors. “This ends up manifesting in the price of land in the economy,” he said. “If the land is expected to be very productive for agriculture, it’s going to cost a lot in the marketplace. As people see the productivity of that land decline because it’s expected to experience more hot days, weaker rights to water, or perhaps less rainfall, people are going to be willing to pay less for that land. So the people who own that land are the real losers. They’re the ones who are losing a valuable asset in real time as the climate deteriorates.”

Mr. Hsaing pointed out that the way we’ve dealt with that in the past is to build infrastructure to supplement and smooth out fluctuations; that infrastructure is laid out in such a way that the water falls in places far from where it’s used, but it can be transported to the place of use in an efficient manner. “But as these climate patterns change, the ability of that infrastructure to be an efficient transportation network is going to change because the precipitation is no longer going to fall where it used to fall, and the demand is going to be growing simultaneously. So you have these simultaneous problems of infrastructure that’s now not allocated in the optimum way, and at the same time that the climate is also reducing the productivity of individual locations, and that’s causing the value of land to depreciate even faster. These are some of the biggest risks to the economy directly.”

Mr. Hsaing said we need to think about how to plan to go forward, but climate change also makes the future more uncertain. “Coming up with long-term plans is going to become increasingly difficult because as the climate changes, we are forced to rely more and more on models and projections of the future and less and less on historical data because that historical data is no longer valid,” he said. “Because of that, we are now not sure what the right course of action is. The uncertainty also creates an additional economic burden on planners and on government in terms of thinking about sort of what should we do moving forward.”

“These are the different angles in which the economy is extremely vulnerable and sort of the challenges that I pose to policymakers in trying to make new long-term investments in this highly uncertain environment,” he said.

Mr. Steyer then turned to Wade Crowfoot and asked him to talk about the impacts he is seeing in California.

“If any of you got in your car after this conference and drove three hours east of here and went to Madera County or Tulare County, Kings County, you would encounter thousands of people that live in homes that don’t have any water,” Mr. Crowfoot said. “They turn on the tap and they don’t have water for drinking. They don’t have water for washing themselves, much less washing their dishes or their clothes.”

“Beginning this spring, our emergency drinking water program at the state started hearing from communities, some very small that basically indicated they were in danger of running out of water in 90 to 120 days,” he said. “These are places that don’t experience frequent cyclical water shortages. In the case of Tulare County, many of the folks that don’t have water have been in these homes for 50 years and never thought they would encounter this problem. So drinking water is probably the most severe and sort of alarming impact of climate-driven drought that we’re seeing.”

“Agriculture is perhaps more well-known,” he said. “UC Davis Center for Watershed Sciences developed a model for calculating the economic impacts to agriculture from the drought. Their model, which has actually borne out to be very accurate, suggested California agriculture will be short about 6.7 million acre feet of water this year. It will make up for that shortage with about 5 million acre feet of groundwater pumping. So about two-thirds gets made up by groundwater pumping.”

“The resulting shortage of 1.7 million acre feet has an economic impact of about $1.5 billion, $1 billion in reduced crop yield and about $500 million in increased groundwater pumping costs,” Mr. Crowfoot said. “That translates to about 20,000 lost jobs, which, of course, has economic impacts, particularly severe in poor farming communities in the Central Valley where we’re literally shipping hundreds of thousands of boxes of emergency food to people that are without food and facing hunger.”

Fire is another drought-related impact, and Cal Fire has reported that fires are burning faster and further than they ever have before, Mr. Crowfoot said, noting that the King Fire advanced 15 miles in one day, something that went far beyond their modeling. “That combustibility this summer has had a human impact on communities like Weed in Siskiyou County, one of our furthest north communities, where almost 200 homes were burned to the ground. It looked like an explosion hit Weed. Again, it was alarming because the combustible nature of vegetation made that fire act like it never had before.”

“Those are just probably what I consider to be the most alarming and impactful impacts of the drought this summer,” he said. “If you accept that essentially climate change is loading the dice on this extreme weather and these are climate-driven events, one could argue that these are really victims of climate change in our state. We so often have heard about victims of climate change in the lowlands of Bangladesh or northern Africa with the droughts. This is impact in our state right now. And so to me, working on climate change and emergency management has connected the dots like never before.”

Aerial view showing Folsom Lake & Dam with low water (drought) behind the dam. Shot 1/16/14. — Folsom Lake, January 2014

“There are a couple more impacts I think we ought to at least raise,” added Peter Gleick. “One is on fisheries. You know, we see the fallowed ag land; we see the fires. We don’t see very well impacts on fisheries, and fisheries are already under stress because of our water conflicts and the allocation of water. In the last drought, which wasn’t that long ago, some of the worst impacts were on some of the local fisheries and local fishing communities. So that’s one thing that I think we need to add.”

“Another more obvious one is hydropower, and this connects to the climate issue,” said Mr. Gleick. “In a normal year now we get about 15 percent of our electricity from hydropower — not that we get a normal year anymore. This year, it will be closer to 6 or 7 percent. The numbers aren’t in yet. The Pacific Institute is just about to release an analysis of this, and our estimate is that probably over the last three years of drought, ratepayers have had to pay an additional $2 billion or so for additional natural gas primarily to replace lost hydropower. And obviously, there’s a climate connection there because it’s increased our greenhouse gas emissions. It’s increased other air quality challenges. So that’s another consequence. And I think all of these things together have to be evaluated.”

Mr. Steyer then asked Noah Diffenbaugh and asked him where we are going on this path. “You were talking about how it’s going to be hot and we’re going to have a lot of years that are hot and dry,” he said. “On the path we’re on, how is that going to change the actual circumstances of Californians? It’s going to be hotter, but what is that really going to mean for us over the next 25 years?”

There are a couple of ways to think about that question, responded Mr. Diffenbaugh. “One is what do we know about projections of the next 25 years,” he said. “Certainly with temperature increasing in western North America we have a good understanding of what that means for snow water. We know the melting point of water quite well: if it’s colder, it’s solid; if it’s warmer, it’s liquid. And we know that in much of western North America we’re already seeing trends towards more liquid water earlier in the year. … We’re likely to see more of it with snow melting earlier and earlier in the year and more of the water that’s falling out of the sky coming as rain rather than snow, which has implications for our water infrastructure and management.”

“I think certainly over the next three-decade timescale that you’re talking about, scientifically we’re seeing a likelihood of an imminent shift towards this more liquid-dominated water delivery from the atmosphere in the western United States,” he said.

The other way to think about your question, where are we headed over the next 30 years, is to think about the vulnerabilities and impacts that we’ve been hearing about in this current event and how often would these conditions occur in terms of the climate, he said. “That’s what we’ve been doing in our research is asking how often do those climate models give a result that looks like this year. … That is something we’re seeing that probably over the next two to three decades where there will be enough warming to pretty much guarantee that when one of these really low precipitation years happens, that it happens in the context of a record high temperature. Over the next three decades we’re pretty likely in the western United States to move outside of the historical envelope of temperature where we’re really seeing pretty much every year being the warmest on record.”

Mr. Steyer said that brings us to the framework of thinking about adapting. “I have a two-part question,” he said to Peter Gleick. “The first one is someone said earlier today there’s plenty of water available in the system, which implies it’s just a question of allocation. That’s the first part of the question. The second part of the question is this. Water isn’t just a resource the way other resources are resources. At some level, water is a public resource. So when you think about water as a public resource and then you put it in the context of markets and you put it in the context of innovation, how should we think about allocating water given that the current system is basically a legal system giving rights to people and protecting the status quo going back as far as 1850? Simple questions, right?”

“In some ways, California has plenty of water,” said Mr. Gleick. “It’s sort of ironic. I have friends who have come from the Middle East to California. They don’t understand why we have a water problem. They have a water problem. So plenty of water in a sense, but not enough water to do everything that everybody wants. And I would modify that to say not enough water to do everything that everybody wants as inefficiently as we’re doing it today.”

“We have to make some decisions,” Mr. Gleick said. “We’re at what we call “peak water.” You might want more water out of the Colorado River, but you can’t have any more because we take it all already. You might want more water out of the Sacramento San Joaquin Basin, but the truth is we’re taking more water out than we ought to if we care about some of these public benefits, the ecosystems which we know now in the 21st century that we ought to be protecting.”

“So part of the question is how do we allocate the water that we already have? And I wish I could say there was an easy answer to that,” said Mr. Gleick. “If we were redesigning the system today from scratch, it would look a lot different, but we’re not. And this gets back to some of the earlier conversations about water markets and water rights. Academically, I sort of like the idea of water markets, but I also understand that we have a water rights structure that has a serious dispute right now about who really has rights to do what? Are they property rights versus use rights? Can you really sell a water right when it’s a public good? How do ecosystems participate in that?”

“So I’m not sure I can answer the question except to say that water is a public good, and yet there are economic benefits and private benefits as well that we want to support, and we have to do a better job of balancing them than we’ve done,” said Mr. Gleick. “I’ll leave it at that.”

Mr. Steyer then asked Sol Hsaing: “If you were going to point to a water system that seemed to bring out the best benefits broadly in society, what one or ones would you point to? And which of those would be adaptive to the western United States?”

Mr. Hsiang admitted he didn’t know everyone’s water systems, but he had some interesting point. “Australia is actually a terrific example,” he said. “I visited Australia around 2008, just in the middle of the drought. Australia has a tremendous amount of highly productive agriculture in the southeastern portion of the country for a river basin that crosses three or four states, and so they had had all sorts of different allocated rights issues and different states had given permission to different people to withdraw water. Then there was a drought and everyone was pulling out all the water. And basically, the government created a new organization to oversee the entire watershed that crossed and superseded state legitimacy.”

“They said, the way we’ve been managing this didn’t recognize sort of the natural features of the environment,” he said. “There’s a normal pattern for how the water flows from one state to the next, but it’s being managed, and the guy upstream doesn’t care what happens to the guy downstream. We should think about this holistically. And so they basically started from scratch. They totally reengineered the whole system, created water markets, and now they have something that people point to as a highly effective trading regime. So I think that’s a great example.”

“When I visited, no one thought that that was going to happen; some people said it was impossible,” Ms. Hsiang said. “But people found a way to make it happen. Initially, some states were more reticent than others, but they were eventually convinced and brought on board. And once people saw how it functioned, and it could actually function in their favor, people were more willing to buy into it.”

Ms. Hsiang said he’d also recently visited Israel, where they conduct agriculture in a ‘fantastically’ dry environment. “The technology that they use in terms of getting more crop for drop is really remarkable. They have irrigation systems where they have little tubes that carry water right to the base of the plant and deliver water directly to the roots … So tremendous water efficiency; a huge amount of value delivered per drop. And so thinking about sort of what types of technology they employ and what can we transplant to this context, I think could be extremely profitable.”

Mr. Steyer then asked Wade Crowfoot about the politics. “You can’t really design a policy in a vacuum, and there are interested parties who have current rights and have current interests and would like to see those protected and enhanced. So when you think about California water policy or western water policy in the context of water rights, who are the biggest players? Who are the people who are pushing the hardest? And how is that reflected in the way that you have to deal in the real world?”

“I think the conventional wisdom or the sound byte that would describe the historical understanding of water in California is this model or paradigm of farms versus fish; cities versus agriculture,” responded Mr. Crowfoot. “This zero sum game where powerful interests are banging up each other and what results is not a lot of systemic improvement to increasing reliability, resilience, ecological sustainability. That’s the script and probably everybody in the room knows that that script exists.”

The crisis of drought has brought opportunity, Mr. Crowfoot said. “We might not have gotten groundwater reform legislation over the finish line if there had not been a drought, and public opinion polls of the water bond prior to this winter suggested it wasn’t largely supported. This water action plan that we put together got everyone’s attention because I think all of these interests understand we have to do something differently.”

Mr. Crowfoot said that the stars are aligned for a new approach. “I think when the governor’s Water Action Plan was released, it had over 100 groups commenting on it. The end result was actually largely embraced by groups because it didn’t take sides; it didn’t suggest there was a silver bullet. It really took this portfolio approach, which is an overused term but it is true. The Water Action Plan says, yes, we need more storage, but it needs to be smart storage. Underground storage with some surface storage and conjunctive use. Yes, we need robust habitat restoration, but we also need to be much more efficient with the water that we use. We need to maximize water recycling, stormwater runoff, et cetera. And so the water bond, to answer part of your previous question, is really a down payment on that portfolio approach. Some of this is about policy and innovation. Some of this is about getting infrastructure to enable that policy innovation.”

“While there are strong political forces with strong opinions around what we should do, we’ve got an opportunity over the next four years to actually make changes that both provide reliability for water users but also help restore the ecological habitat and prepare us for climate change,” said Mr. Crowfoot. “I’m fairly optimistic about what we can do politically.”

Mr. Steyer then asked Mr. Gleick about the dichotomy between adaptation and mitigation. “When you think about society trying to deal with both of those things simultaneously, do you see the pressure on adaptation that everybody obviously feels is a local human pressure pretty much regardless of where you are? Can you conceive of society being able to deal with both at the same time? In a lot of places they’re dealing with specific problems the way we are, on an adaptation basis that are expensive, real, and immediate. Does that make mitigation go to the backburner?”

“I think the good news here is that we’re already doing some remarkable things and we’re making a lot of progress,” Mr. Gleick said. “Agriculture is making changes … We have drip irrigation, although we could have a lot more. All of our sectors could be more efficient. The kinds of wastewater treatment and reuse is an adaptation to a climate where there’s not enough water to go around. Stormwater capture is an adaptation. The groundwater work that we’re talking about. I think those are the right things that we want to do in the context of climate change, with or without climate change. In a normal year in California, there’s not enough water to go around. This isn’t just a drought climate change issue.”

There is a very strong link between our energy use and our water use, Mr. Gleick said. “There’s been a lot of discussion about the water requirements for our energy systems. Power plants take a lot of water; that’s true. But the flipside of that is it takes a tremendous amount of energy to run our water systems. The biggest single consumer power in the state of California is the pumps that lift water over the Tehachapi Mountains in the Los Angeles Basin, which is part of the reason why pumping water from Canada or the Mississippi River isn’t going to happen. It’s hugely energy intensive. Saving a gallon in the Los Angeles Basin is a smarter idea than saving the same gallon of water in San Francisco – not that that’s a bad idea either, because it takes more energy to get it there and more greenhouse gases.”

“If we think about energy and water together, there are all sorts of opportunities to improve the efficiency of our system, meet our water needs, cut our energy use, and reduce our greenhouse gas emissions,” said Mr. Gleick. “That’s the mitigation adaptation link. That’s why we have a tremendous opportunity to do both at a time when we had no choice but to do both.”

The floor was then opened for audience questions. “This is about the effect on the handling of climate change from the fairly well-organized political machinery that would rather not have any mitigation and obscure the cost of adaptation and seems to want to keep science out of public policy,” one of the audience members asked. “The question for you is to what extent do you see this both in California and nationally, since that matters? And what can the rest of us do to make sure that science informs public policy?”

Mr. Hsiang said that this kind of forum with these issues being discussed and being broadcast on the web is really critical. “There’s a lot that we can do to improve our resilience to extreme events, for example, in the current climate, and those are actions that we can take that are going to also improve our resilience to climate change,” he said. “In the U.S. over the last decade, we’ve had something on the order of 70 individual extreme weather and climate disasters that have each had at least a billion dollars in losses, and a number of them much more than one billion. So that’s an indication that we’re not adapted to the climate that we have right now, and so we can improve without there being a lot of debate about whether mitigation versus adaptation. If it’s a good idea now and it’s going to give us increasing resilience in the future, then it seems like a relatively clear path forward.”

“Part of the answer lies in continuing to build the model of what we’ve been able to build in California,” responded Mr. Crowfoot. “We have the eighth largest economy in the world. Our economic recovery has outpaced the rest of the country while we’ve reduced emissions, and we’re going to meet our AB32 goal and then with the governor’s leadership, go beyond that while we’re bringing on a third of our energy system will be renewable, while we’re plugging in 100,000 cars (electric vehicles), while our energy footprint is half of the rest of the country. So part of it is this is not a boutique economy. This is a large, robust economy that’s showing we can actually grow and reduce climate emissions or carbon emissions.”

The Governor is out spreading the message, noted Mr. Crowfoot. “The governor and our administration are deeply involved with China, India, Mexico; the governor spoke at the United Nations last month. … He’s talked about that publicly. So a part of it is showing we can continue to reduce emissions in California while growing our economy, and then part of that is sharing that with the rest of the world and finding those other exemplary climate leaders to help move our nation states towards international agreement on climate.”

“But you’re not talking about deep blue states like California; you’re talking about states where the politicians who understand that there are human immediate needs and problems that they’d like taken care of,” countered Mr. Steyer. “They’d like billions of dollars of federal aid, but they really don’t want to spend any time or conversation on mitigation because they really aren’t sure if climate change is happening, and they’re not scientists. … And so the question is how is that line of argument, which isn’t much of a line of argument, going to be countered so that they eventually have to come in and deal with the realities and the scientific research?”

“That’s an ongoing process of trying to counter those statements and do exactly what Peter is talking about, which is to combine the two,” continued Mr. Steyer. “We know we have to deal with adaptation, but we also have to deal with mitigation, because if you really listen to what Noah is saying, if we continue on this path, our current adaptation plans become mute. And so the question is what do you say to someone who says I am not a scientist? Well, they’re also not a doctor or an architect. So there are a number of other policy issues where they don’t have a Ph.D., and by that line of argument shouldn’t have anything to say either.”

“I think over time this is going to be kind of a question of whether Americans see through that,” Mr. Steyer said. “And do they see it not so much in terms of the scientific argument but do they see that as an unacceptable answer for someone holding a really high office of trust and making decisions on their behalf on the most essential questions? That’s really going to be the question.”

Another audience member asked a question about storage. “You guys made a very strong case about the loss of snow pack. One of the immediate reactions is more storage. Storage is part of the bond. I notice that Lake Meade and Lake Powell are not filling up. What’s the situation now in terms of a large off stream reservoir potentially in California and whether that makes sense given the difference in hydraulic cycles? Will we be able to essentially replicate the Sierra snowpack with conventional storage or not? Is there a relationship here between the climate science and the cost effectiveness of the traditional reservoir answer, or are we going to look for more modern storage answers than the traditional one?”

“The easy response to the “we’re losing snow pack storage” is build more storage,” responded Peter Gleick. “But we don’t live in that world anymore. We can never replace the loss of snow pack storage with new storage in California, because we built on all the good dam sites, and some not so good dam sites. We might build a couple more reservoirs. There might be one off stream storage site reservoir, but that’s not going to solve our problem. There is enormous potential for groundwater storage, and I think rethinking what we mean by storage is the answer. It’s not to say yes storage, no storage; it’s what kind of storage? We over pump groundwater even in a good year, and enormously in a bad year. But if we can recharge groundwater really effectively, at the same time as we’re restoring ecosystems because we’re restoring wetlands that permit recharge, that storage could really help with the climate management problem. But even that may not be enough. We may have to change the way we think about seasonal management overall.”