Al Armendariz’s big mouth cost him his job as a regional administrator of the Environmental Protection Agency. Now that he’s working for the Sierra Club, Armendariz appears even more opinionated about the industry he once regulated.

In his first comments since resigning from EPA in April, Armendariz unloaded on the coal industry, called President Obama the most environmental president ever, and attacked the state of Texas for fighting the EPA in court. He also addressed the controversy surrounding his comments comparing the EPA’s philosophy to the brutal tactics used by the ancient Roman army to intimidate its adversaries.

Armendariz’s most pointed comments to the Texas Tribune came on the subject of coal. He’s spearheading the EPA’s Beyond Coal campaign in Texas, which, according to Armendariz, basically amounts to destroying the industry.

TT: What made you decide to join the Sierra Club?

Armendariz: The coal industry is destroying communities, it’s poisoning our air and our water and our land. And it’s damaging our climate in Texas. And I am very concerned about what climate change is going to do to this state, and I’m very concerned about the role of the coal industry in causing climate change. I wanted to join an organization with a track record of success in taking on the coal industry, and I wanted to join an organization that I felt I could contribute to, and contribute to additional success. And I found that in the Sierra Club and in the coal campaign.

TT: So you’re going to be working with the Beyond Coal campaign. What does that mean you’ll be doing exactly?

Armendariz: I have a small handful of objectives. The first is to stop the construction of any new coal plants in Texas. And also to stop the expansion of any additional coal exports from Texas ports [to] overseas. The second objective is to work on the transition … to clean renewable sources of energy. And the third objective is to work really with all of the stakeholders in the state to further the development of renewable sources of energy, like wind and solar and geothermal.

TT: If we shut down coal plants, we still obviously have to get power. Is natural gas part of the solution?

Armendariz: My principal objective is to replace our use of coal with renewable energy sources like wind and solar and geothermal, with efforts at energy efficiency to reduce demand. If we’re going to use natural gas to replace some of the existing coal capacity, I think we should use it as little as possible. And if we’re going to use it, I do think it is incumbent on the natural gas industry to assure the highest standards of protection to the air and the water of the communities that live near the natural gas fields.

When he asked by the Texas Tribune about America’s natural gas boom — thanks to oft-maligned fracking technology — Armendariz, not surpringly, voiced alarm as well. It would seem he wants to rely solely on renewable energy, which accounted for approximately 9% of U.S. energy consumption in 2011, according to the U.S. Energy Information Administration. See chart below.

Can the United States produce enough electricity from wind, solar and geothermal? According to the government’s own data, wind accounted for 1.20% of energy consumption in 2011, solar was at 0.16% and geothermal was slightly better at 0.23%. Those numbers are minuscule compared to coal’s 20%, and yet Armendariz is now on a warpath to destroy the coal industry.

Interestingly, Armendariz said in the interview he enjoyed good relations with the energy industry as an EPA administrator. That would contrast sharply with his comments in the video that surfaced earlier this year describing the EPA’s approach:

I was in a meeting once and I gave an analogy to my staff about my philosophy of enforcement, and I think it was probably a little crude and maybe not appropriate for the meeting but I’ll go ahead and tell you what I said. It was kind of like how the Romans used to conquer little villages in the Mediterranean. They’d go into a little Turkish town somewhere, they’d find the first five guys they saw and they’d crucify them.

And then you know that town was really easy to manage for the next few years. And so you make examples out of people who are in this case not compliant with the law. Find people who are not compliant with the law, and you hit them as hard as you can and you make examples out of them, and there is a deterrent effect there.

Armendariz later apologized and resigned. Texas Tribune didn’t ask him about his comments directly, but did wonder why he skipped a U.S. House hearing this spring. Armendariz said it wouldn’t have been productive in light of his registration in April.

Another interesting tidbit: Armendariz said it was unfortunate the state of Texas wouldn’t work in “partnership with the EPA”. Attorney General Greg Abbott took the EPA to court instead, attacking regulations imposed by government bureaucrats at EPA.

Despite some complaints from the environmentalist left that President Obama hasn’t done enough, Armendariz is still high on his old boss. “I think really without hesitation that he is going to go down as the most environmental of any of our presidents,” he said.