UC Berkeley professor Daniel Kammen recently achieved some notoriety when he resigned from his role as science advisor to the Trump administration, in protest over the president’s response to the Charlottesville demonstrations. The first letter of each paragraph in his letter to the president spelled out “impeach.”

Mr. President, I am resigning as Science Envoy. Your response to Charlottesville enables racism, sexism, & harms our country and planet. pic.twitter.com/eWzDc5Yw6t — Daniel M Kammen (@dan_kammen) August 23, 2017

Coming amidst the storm of criticism toward Trump in the wake of Charlottesville, Kammen’s letter was broadly amplified in the media, serving as yet another signal of the president’s alienation.

Though it got fewer headlines, Kammen was also co-author on a recent paper critiquing the work of Stanford’s Mark Jacobson on 100 percent renewable energy. That work has been broadly embraced by climate activists, so the ensuing debate was quite heated (and protracted).

From Berkeley, Kammen has been an adviser to the Obama administration and also to California activists and legislators on many of California’s recent decarbonization initiatives. In short, he seems to be in everything, energy-wise.

It’s difficult to find a more impressive CV in clean energy than Kammen’s. For decades now he has done peer-reviewed research on clean energy, contributed to IPCC reports, served on various boards and advisory committees, testified to Congress, and served both Republican and Democratic administrations in a range of advisory roles. He also founded and runs the Renewable and Appropriate Energy Laboratory (RAEL) at UC Berkeley, where he holds simultaneous appointments in the Energy and Resources Group, the Goldman School of Public Policy, and the department of Nuclear Engineering.

I asked him about all these recent controversies — his resignation, 100 percent renewables, the recent Department of Energy report on grid reliability, coal’s supposed contribution to grid resilience (“so dumb it’s not even wrong,” he says), and more — when I reached him on the phone recently. Our conversation has been edited for length and clarity.

David Roberts

What is the science envoy position and why did you feel you could no longer serve?

Dan Kammen

The science envoy is a position that was created under President Barack Obama. There’s generally four or five of them a year. It’s a position external to the State Department — you’re appointed by the secretary, but you’re not paid. Some of my hate mail says, “thank goodness you’re not drawing a salary any more” [laughter], but there was no federal salary.

Science envoy is somewhere between honorific and operational, based around partnering with American embassies. My appointment, by Secretary of State John Kerry, was for energy and climate partnerships with Middle Eastern and African governments. I worked very hard with a number of governments — Morocco, Jordan, Kenya, Uganda, Tanzania — and was focusing on how to build pro-sustainable-energy, pro-business partnerships around energy access, quality of life for the poor, and energy services to provide health care.

David Roberts

Was quitting about feeling like you couldn’t do the work effectively any more, or was it more about making a statement?

Dan Kammen

We were quite effective. We launched multiple conferences; got exchange of students between the US and those countries; got Moroccan and Kenyan teams involved in business competitions; worked on a women’s center in Kenya to help poor Kenyan women and children have access to state water services, education, and job training. We were very effective.

But I couldn’t work for a president who is directing us away from international partnerships such as Paris climate accord, away from civility, by not condemning racism at home, clearly and forcefully. The reason I embedded “impeach” in my message is, as a private citizen, I don’t even think there’s room to debate that Mr. Trump is putting his own business and personal interests over that of the country.

That is unacceptable in a president. I could not work for him. I understand why some people feel torn, don’t want to leave the job and the good work, but I couldn’t, with a straight face, work for someone who has demonstrated, almost on a daily basis, that he values himself more than the country.

David Roberts

Do you think he’s committed impeachable offenses? How serious were you about that?

Dan Kammen

I was quite serious. I mean, I am not an elected member of the US House or Senate. Their definition of “impeachable” is different than a private citizen’s. But if one accepts that the commander in chief is not putting the country first, they’re putting themselves first, in a very straightforward if informal way, that is an impeachable offense.

David Roberts

I wanted to ask you about the [Department of Energy] grid-reliability study that just came out. The entire energy world was waiting on it breathlessly, convinced that Rick Perry’s DOE would try to distort it to make a case for coal. It’s debatable how much that happened, but on the substance: Is there anything to this notion that baseload plants [usually coal and nuclear] are necessary for grid resilience?

Dan Kammen

These people who think renewables don’t provide resilience are simply wrong. We’ve seen over and over again that renewables are not better or worse than fossil fuels, they’re different than fossil fuels. To have a grid with a very high level of renewables requires a level of coordination.

The places that are most aggressive on deploying renewables — the Californias, New Yorks, Germanys, etc. — are already investing in storage to complement it. But in most of the [US], renewables are not a large enough fraction yet to require anything beyond coordinating with gas.

So to say that renewables reduce reliability or resilience is just factually wrong. It’s a question of integration and coordination, and surprise, surprise, that’s what state or regional system operators, the so-called ISOs of the country, are designed to do.

You get ridiculously silly arguments against [renewables]. Last week, during the eclipse, I got messages from conservative utilities and right-wing groups saying, oh, well, this demonstrates the infeasibility of solar. I said, “have you ever heard of nighttime?”

The facts are that a diverse energy system with a large amount of renewables looks different than an old-style system, but it is, in fact, as or more reliable.

David Roberts

So you would say, categorically, that the shutting down of so-called baseload power plants in the US isn’t a problem?

Dan Kammen

You can make it a problem if you shut down baseload plants and don’t bring other capacity online. That would just be bad planning.

Renewables and natural gas are flexible, much quicker to construct than traditional technologies, have lower capital costs, and easier siting issues. It’s true that you need to think about them in conjunction. The real challenge is not the one right now — with low gas prices and low prices for wind and solar, you can beat coal and nuclear to the punch by just installing. But in 10 or 15 years, when we have to get rid of natural gas too, changing those plants out will be tricky. Natural gas is a wonderful, flexible partner [for renewables].

But in places like California, we already have a storage mandate. We’re already requiring utilities to install storage: batteries, flywheels, there’s even a proposal right now to have a train that basically carts rock uphill.

And I haven’t even talked about the really pervasive version [of energy storage]. In California, we have 10 percent of all electric vehicles in the world — about 200,000 out of 2 million — and that is a ready-made distributed-storage mechanism.

We need to get off of natural gas by 2025. But that’s not so much an issue today, so these arguments against [renewable energy] are really silly. We are in a situation where clean and cheap go together. Whereas, dirty and slow go together — that is the legacy of coal.

David Roberts

What about the idea that terrorist attacks could take out key natural gas pipelines and leave the whole eastern seaboard in the dark … unless we have giant piles of coal laying around, ready to go?

Dan Kammen

Even with these really huge natural disasters, our natural gas system has actually been fairly resilient. The idea that piles of coal are going to provide us with any sort of security is ... it’s so dumb it’s not even wrong.

David Roberts

The other big debate you’ve been involved in lately is about a grid running on 100 percent renewable energy — specifically, whether it’s realistic to get there. It’s another subject that has divided the climate community. [I wrote two articles on it, a beginner’s guide to the debate and a more in-depth look.] You were part of a big critique of Mark Jacobson’s work on that subject at Stanford. What is the practical upshot of that debate for today’s decisions? Why does it matter?

Dan Kammen

I was one of 21 authors on that paper. The basic story is that we’ve known for 50 years that you could run the economy off of renewables. The world receives 14,000 times as much solar power each day as it needs. The reason why this unusual group of 21 authors banded together and wrote a paper is that you have to do your math right. And, unfortunately, I would say [Jacobson’s] wind-water-solar work does not do the math right.

The 21 authors in the critique paper aren’t all aligned on which technologies they support — no surprise. Many of us build detailed, realistic models of the grid and find that the 100 percent renewable target is entirely achievable. In fact, in California, we are voting right now on Senate Bill 100 that would require California to hit 100 percent renewables in 2045. I am strongly behind that, because my model, called SWITCH, is one of many models being used here in the West that finds that that is an achievable goal. But you have to do your math right to be a credible part of the conversation.

David Roberts

So your personal objection was not to the concept of 100 percent renewables.

Dan Kammen

That’s correct. Papers written in Nature and Science all highlight the pathways to get to 80 percent or more decarbonized by 2030 or 2040. Of course, that last bit is the most expensive; it requires the most planning and integration. But the goal is achievable. We’ve known we can do it for a long time.

David Roberts

The nut of the debate seems to be whether we’ll be able to replace all that natural gas — which, as you said, is such a nice partner for renewables — without using some nuclear or CCS.

Dan Kammen

I am a professor of nuclear engineering. But when we put current and projected future prices for different technologies — renewables, CCS, nuclear, etc. — in my model, which simply optimizes around reliability and cost, it never chooses nuclear. Nuclear is so expensive and takes so long to build, and we need to solve the climate problem by 2050.

I’m actually exceedingly bullish that nuclear will play a large role in the 2060, 2070, 2080 range. I study different nuclear technologies and I’m quite excited about pebble bed reactors, liquid metal reactors, traveling wave reactors, and small modular reactors. But they’re going to have to meet price, reliability, and risk barriers that, right now, look really challenging for the nuclear industry to even replace the plants we have, let alone expand their role.

David Roberts

The response is typically that variable renewables begin to drop in value as you put more on the grid.

Dan Kammen

That’s just not true. I mean, it’s true if you think we’re never going to progress on storage. But storage has all of the same fundamentals as solar, meaning there’s multiple technologies, it is scalable, we have only just begun to research in any significant way ... I just published a paper in Nature last month [arguing that] storage is progressing today faster than wind or solar ever did — just starting much more recently.

The papers many of us have been writing are finding that storage technologies are even more diverse than solar technologies. There’s chemical storage batteries, flywheels, flow batteries, pumped hydro, thermodynamic versions where you store heat either in other systems or in compressed air — storage is incredibly diverse, but no one worked on it for a long time.

Now my students come into my research group and they say, “Well, solar, that’s exciting, but that’s pretty far down the learning curve.” Maybe they’ll work on quantum dots or solar cells, but storage is where it’s at. My best and brightest material science focused students today are going into storage.

We’re seeing Hawaii, California, Arizona, and New York starting to install large-scale storage arrays that are megawatt hours’ worth, at prices 50 percent below what they thought when they started the project.

David Roberts

You don’t see any problem with storage scaling up to the point that it can handle the variability of wind and solar.

Dan Kammen

I do not see a problem. I certainly hope nuclear plays a role. I don’t see a role for CCS yet. Perhaps there’s a small role in China or India. But in the United States, CCS essentially means burning 20 to 30 percent more coal than a current plant and doing nothing to address the water, air, and other issues.

David Roberts

Bioenergy with CCS is supposed to be the grand hope, right?

Dan Kammen

I would disagree. It might play a role, but I don’t think it’s going to be a transformative one.

David Roberts

Another big energy debate you’re well-placed to have perspective on is about California and carbon. A recent report found that progress in the state in electricity is on track, but progress on cars is way behind.

Dan Kammen

I just think that’s wrong. I mean, California has more than 200,000 electric vehicles in place. Now, our total vehicle fleet is about 17 million, but California just recently started.

When [the state] said it will hit a million electric vehicles by 2020, people scoffed. Well, if you go back five years, we said we’re going to have a million solar rooftops by 2020; people scoffed at that too. Now we have 600,000 — two-thirds of all solar rooftops in the United States.

California will make or get close to its target of a million electric vehicles in 2020.

David Roberts

EVs are the answer?

Dan Kammen

Low-carbon transportation — including better mass transit, lots of EVs, better neighborhood design — is going to handle that issue on time and under budget.

No one ever thought that California, the car culture of all car cultures, could electrify its fleet, and now we’re talking about all kinds of clever ideas like, when you buy a home, to include an electric vehicle in the mortgage. If you turn in the title for a gas burning car, you get a discount beyond that. No one, no futurist, no one at Long Now or Singularity University, thought that California would become a car manufacturing leader, which we are today.

David Roberts

What is the rough balance of just switching out [internal combustion engine] cars in for EVs versus better zoning, better transit, and solving the housing crisis?

Dan Kammen

That’s a great question. I don’t think anyone can give you an easy answer. But my research team at Berkeley, along with others, we’re trying things out.

We have a project in a lower-middle income area of Oakland called the Eco Block. We’re working with 40 homeowners to wire their homes together to share rooftop solar, to disconnect them from the city sewage system to have their own grey-water and black-water recycling system, and to have shared electric vehicles, their own neighborhood version of Zipcar. We’re physically building it.

I have partners in Paris, Tokyo, and Johannesburg that we talk to all the time, because they’re trying the same things.

So what fraction is going to be clean vehicles versus smarter housing? I don’t know, but California has a law, Senate Bill 375, that requires new planning decisions to take into account and reduce vehicle miles traveled. Early efforts like that are going to give us data to start doing this.

When you talk to 20-year-olds today, they don’t see owning a car as a good thing the way people 45 and older do. They see owning a car as a big, unnecessary hassle. They want access to transportation. There is a huge culture change that old people like myself need to catch up with.

David Roberts

But if you talk to the old people who live in single-family detached homes in the middle of urban areas, they definitely don’t want more housing or transit.

Dan Kammen

Unfortunately, the definition of being an old, wealthy person is often someone who resists what’s coming next.

We now have younger people saying they want “walk to latte” and “walk to mass transit” housing. They do want to be able to access that electric vehicle to go skiing a couple times a year, but they don’t want to own it. The basics of 1950s-oriented consumerism are under a positive threat from the younger generation. I definitely side with that kind of change.

I actually think that — while 10 years ago, climate change was almost insurmountable, and it’s still a huge challenge — I would argue that greed and inequality have replaced climate change as the impossible problem.

It doesn’t mean we’re not going to have to work incredibly hard on climate change. But what you’re talking about now are the baked in, inherent challenges between the old and young, the entitled and not entitled. That’s going to be a bigger story over time, assuming we solve the climate change problem. If we don’t solve that, we don’t have the luxury of solving these other social problems.