SNL Energy recently interviewed Michael Brune, executive director of the Sierra Club, about the organization's stronger tone on natural gas and the general state of the energy industry.

Brune, who started as executive director in March 2010 after leading the Rainforest Action Network, is a prominent advocate for clean energy and recently said the nation should, during the transition away from coal, leapfrog natural gas.

Below is an edited transcript of a March 28 phone interview.

SNL Energy: The club has taken a much stronger public stance on natural gas in recent weeks. Can you talk about that shift in strategy?

Michael Brune: These are changes that have probably been a couple years in coming, so I'd say we've taken a noticeably stronger stance on gas over the last few years. The reason for it is primarily, to simplify it, because of two things. One, we're getting more information about the increased risks that gas poses to our air and water climate, especially in communities. We're adjusting our strategies accordingly.

The second reason is just that policymakers have not been responding at the state level, federally and within the industry itself. We've been increasingly alarmed at the lack of movement from regulators and the industry to address some of these growing concerns.

Meanwhile, the natural gas industry is pleased that their talking points have been worked into speeches from high-level administration members and the president himself. Obviously, the president is working to get re-elected and energy has become a hot-button issue. So how has Sierra Club been working to shift the debate back to where it stood four years ago, when climate legislation was the energy talking point of the Obama campaign?

The best place for there to be a debate about climate is for the president to talk about climate. Right now, we have the Republican Party running away from science as fast as it can and not acknowledging the reality of what's happening all around the country and all around the world. Forests are burning and drying out, glaciers are melting, people are being displaced, extreme weather events are increasing. There's not even an acknowledgement coming from the Republican Party of this reality.

Democrats, on the other hand, and the president in particular, mention climate change rarely, if at all. That is a dramatic change from how it was just 3.5 to four years ago. So our approach is, we want to recognize real achievement when we see it. The administration has made notable and in some cases historic progress on a number of fronts regarding energy. I would highlight the proposed car rule, which will practically double fuel efficiency, the mercury rule last year, which limits arsenic toxins like dioxin and mercury from coal plants. [The recent] rule on carbon pollution is also a good one. So we want to recognize and celebrate those achievements.

At the same time, and I put a blog post up about this a couple days ago, we want to say that the president does need to lead more on climate change and draw a strong connection to how a change in climate produces very real and very negative impacts on people's lives. Whereas, effectively addressing the climate challenge will bring great benefits to people. He hasn't made that case very strongly, or consistently, and it is his job to do so.

Yesterday's carbon rule made it sound like natural gas plants are the winner, if 95% of natural gas combined-cycle plants will meet the carbon standard. So going forward, the writing on the wall is that coal plants won't be built unless carbon capture and sequestration becomes more economically viable, and gas plants will be built. Do you have any reaction; do you think the rule was strong enough on the carbon front?

I would say the rule is helpful in that it forces coal to clean up, and then we'll see if it can compete with other fuel sources. But clearly, we're not going to solve our climate challenge with a single piece of legislation, even if it's an economywide piece, nor are we going to solve it with a single rulemaking from EPA.

We view this rule as being helpful in bringing the coal industry up to modern pollution standards. But we realize now that we have a dogfight in the U.S. in terms of what replaces coal. Will it be gas, which creates a whole new set of challenges? Or will it be a combination of demand response, greater efficiency, solar plus wind, a whole package of solutions?

If it is gas, I think we're going to be wrestling with our climate challenge far longer than we should.

Is nuclear something Sierra Club would get behind in the future? If you're not running fossil fuels, there has to be a couple of solutions for electricity demand in the U.S.

We don't support the expansion of the nuclear industry in the U.S. To compare different types of energy sources, we use a few basic types of criteria. One is, what's the cleanest source, another one is what's the cheapest, the third would be what's safest, and the fourth is what can come online most quickly? If you look at nuclear power, particularly new nuclear power, it ranks either last or almost last in all four categories. We just don't see how new nuclear power in the U.S. is responsible, it's not economically responsible, and it's not environmentally responsible.

However, nuclear is producing a little bit less than 20% of our electricity in the U.S. So how we phase out nuclear power is something that should be decided on a plant-by-plant basis. The top priority for the club is to retire existing coal plants and replace them with clean energy, and then to phase out other dirty sources, plant by plant, as quickly as we can.

In your view, renewables are ready for the stage? If you are trying to leapfrog natural gas and you are phasing out some nuclear, don't you run the risk of prolonging our current generating fleet? How do you fill in the demand gap?

The goal is to get off dirty energy as quickly and effectively and cost-effectively as we can. Stopping new coal plants and retiring existing coal plants is the top priority because coal is the dirtiest energy source. We want to use as little gas in the process and to prevent a massive build-out of gas infrastructure in the U.S.

We do think that solar and wind and efficiency are ready for prime time. We've seen dramatic growth over the last couple years and over the last couple decades. Over the last couple years, the costs have come down so much that we're seeing fairly significant penetration into energy markets. Iowa's got 20% wind, South Dakota is 20% wind, Texas wind continues to grow significantly, and California will soon hit the 20% threshold and keep pushing forward to 33% [renewables] by the end of the decade. These are real numbers with some significance attached to them. It's not just hippies on hilltops anymore living off the grid. We think the prospects for clean energy to fix dirty energy down the road are more promising than they have ever been, and they are getting stronger.

We've seen fossil fuel producers increasingly looking to export their domestic production. Coal is already sent overseas on a small scale, and natural gas appears to be next. Are you concerned that even if the U.S. moves toward clean energy, the carbon impact will just be relocated?

Yes, I am; we are. That's why we're fighting the export of coal to other countries and we're opposing LNG terminals to be built in the U.S. We know that the world economy is going to be based on clean energy in the 21st century for our planet to thrive and the people on the planet to thrive. We know that the question and the challenge is, Do we make investments now that will get us there more quickly? Or do we perpetuate this transition and make it more difficult? We don't think that exporting fossil fuels from the U.S. is a smart way to address climate, and we don't think it's a sustainable way to build our economy.

Do you hope Congress or the administration can step in here? Or is this a grassroots battle for now?

We need leadership at all levels. We do need Congress to wake up and begin to develop solutions to some of America's biggest problems. We have applauded the president for taking many strong steps toward clean energy and are imploring him to use his full power to dig a little deeper and push a little harder.

We are seeing some leadership at the state level, some leadership at the corporate level. Whenever we see it, we applaud that leadership and are looking to find partners wherever we can. At the grass roots, in city and state government, regionally within the private sector and inside the Beltway, we need innovation, imagination and determination wherever it can be found.

One elephant in the room is the recent concession that, yes, the Sierra Club did accept millions of dollars in donations from the natural gas industry. The Natural Gas Reform Campaign has been working on these issues for more than a year, and that decision was made under your predecessor's watch. But cynics can't help but point out that the anti-gas volume has been cranked up lately. What has been most difficult in regard to that announcement and subsequent fallout?

The toughest thing has just been to witness how people have been very disappointed and upset by what the Sierra Club did. I went through that same process of finding out about these contributions, extricating ourselves from that relationship, managing the organization's finances and trying to lead through this a couple years ago. So when this became public, the biggest challenge has been to talk our members and volunteer leaders and activists through this whole process. It has taken a lot of phone calls and a lot of emails and letters and in-person meetings for people to process all this information.

I understand people were angry because I was, too. I understand they were disappointed by what was done, and I felt the same way. I think what we're working toward is making sure that we have an internal governance so that something like this never happens again. We are redoubling our efforts to support communities that are facing fracking all across the country and through the campaign, which has been growing for the last few years and continues to grow.

What we're trying to do, which is frankly very difficult to do, is simultaneously support all of the communities who are very concerned about a coal plant in their back yard, or mountaintop removal mining site down the road, as well as support the communities who are very concerned about fracking and what it means for their water, air and community. And to make sure that any Sierra Club members knows they can count on the Sierra Club for support when they want to fight pollution, regardless of the source.

Basically, what we're trying to do is unify all activists against fossil fuels and to do it in a way that challenges each of us fighting dirty energy on one hand and the other hand pushing strongly for clean energy. We can't just be about all the things we oppose. We have to be very creative and productive in creating the clean energy economy that we've been demanding for a long time.