Back in 2011, during the GOP presidential primary, Rick Perry spoke during a debate and tried to list the three federal agencies he’d abolish if elected to the White House.

“And I will tell you,” Perry said, “it is three agencies of government when I get there that are gone. Commerce, Education, and the … what's the third one there? Let's see."

Then he stumbled. He couldn’t recall the third. When coaxed by other candidates and the moderator — did he mean the Environmental Protection Agency, maybe? — he drew a blank. “Sorry,” he said as he grinned sheepishly at the cameras. “Oops.”

A few minutes later, Perry remembered — it was the Department of Energy he wanted to get rid of! That was it.

That brain fart ended Perry’s presidential aspirations in 2012. But it wasn’t the end of the story: Donald Trump has reportedly picked Rick Perry to lead the Energy Department, the very agency he once kinda sorta wanted to get rid of. And while it’s not clear that Perry still wants to abolish the DOE, the climate-denying, fossil fuel–loving former governor from Texas is likely to usher in major changes to this key agency.

The Department of Energy doesn’t just do energy — it mainly handles nuclear weapons

The Department of Energy is a strange beast, cobbled together from existing agencies in 1977 at a time when oil crises were raging and calls for a national energy policy were in the air. But energy is only a small fraction of what it actually does. Today, DOE’s $32 billion budget can basically be split into four big categories:

40 percent, or $13 billion, is dedicated to designing, maintaining, and testing the US nuclear weapons arsenal. Much of this work is done at the sprawling array of national research labs that the DOE operates around the country, like Los Alamos in New Mexico.

20 percent, or $6 billion, is dedicated to handling nuclear waste and cleaning up the messes spawned by the nuclear weapons programs of the Cold War era — such as the contaminated soil around Oak Ridge National Lab in Tennessee.

Another 20 percent goes toward basic science research in the national labs — things like high-energy physics, nuclear physics, and computing research.

Finally, only 20 percent is devoted to what we typically think of as “energy” programs, including R&D toward new oil and gas drilling techniques, advanced nuclear reactors, renewables, and energy efficiency. There’s also ARPA-e, a federal venture capital fund of sorts that funds long-shot energy technologies like batteries, advanced wind turbines, and cleaner biofuels.

The nuclear weapons and environmental cleanup programs tend to remain fixed from administration to administration. But the energy programs have changed significantly with each new president. George W. Bush, for instance, asked Congress to prioritize nuclear power and carbon capture and storage technology for coal. Under President Barack Obama, meanwhile, the Department of Energy has greatly expanded a variety of clean energy programs — the stimulus bill of 2009 created massive loan guarantee programs for solar, battery, and electric car companies.

These programs have played an important role in developing new energy technologies. The techniques behind hydraulic fracturing, which has flooded the US with cheap shale gas, were refined with help from the Department of Energy. Elon Musk’s electric car company, Tesla, benefited from an early DOE loan from the Advanced Technology Vehicles Manufacturing program. The agency has also played a supporting role in driving down solar costs with its Sunshot Initiative.

Donald Trump’s transition team, for its part, has generally signaled that it wants to tilt the Energy Department’s focus away from renewables and back toward programs that support oil and gas drilling (and possibly nuclear power). And Rick Perry — an inveterate climate denier who was governor for 15 years of one of America’s most important oil and gas states — is a natural fit to do just that.

Perry has a long history of supporting oil, gas, and coal — though also wind

As governor of Texas from 2000 to 2015, Perry strongly favored expanded fossil fuel production, as this great piece from Kate Galbraith of the Texas Tribune explored. He has also consistently denied the reality of global warming, claiming in 2011 that “[t]here are a substantial number of scientists who have manipulated data so that they will have dollars rolling into their projects." (There is no evidence whatsoever of this.)

Perry’s outlook was largely shaped by opportunities in Texas, a state rich in fossil fuels. During his tenure, the rise of hydraulic fracturing and horizontal drilling brought about a surge of oil and gas drilling in places like Texas’s Eagle Ford and Barnett shale formations. Between 2000 and 2015, natural gas production rose 42 percent in Texas. Oil production rose 280 percent.

Perry generally kept in place the loose regulations on oil and gas that existed under his predecessor in Texas, George W. Bush. He was a prominent critic of President Obama’s push for tighter regulations on fossil fuel pollution, and accused Obama of “trying to scare people, and saying that hydraulic fracking somehow or another is going to damage the groundwater.” (Just today, the EPA put out a major report finding that fracking can affect drinking water in certain circumstances.)

He was also a prominent supporter of coal power during an era when the rest of the country has been slowly moving away from coal in favor of cheaper (and cleaner) natural gas. In 2005, he signed an executive order to expedite approval of coal plants — though a major deal by local utility TXU to build 11 new coal plants, which was fiercely opposed by environmental groups, eventually fell through.

But, interestingly, Perry was also a major supporter of Texas’s fast-growing wind industry, which first began budding under Bush. In 2005, Perry signed a bill requiring Texas to get 5,880 megawatts of renewables capacity by 2015 — Texas has since surpassed 10,000 megawatts. He also supported a $5 billion project to build transmission lines that would bring power from windy West Texas down to the state’s major metro areas. The state now produces more wind energy than any in the country. The wind boom wasn’t all Perry’s doing — federal tax credits for wind arguably played a bigger role — but he didn’t stand in its way.

How Perry might reshape the Energy Department

Perry has a very different background from his Obama-era predecessors — Steven Chu, a Nobel Prize–winning physicist, and Ernest Moniz, a nuclear physicist. In 2010, after the massive BP oil spill in the Gulf of Mexico, Perry called the disaster an “act of God” and warned against tightening regulations in response; Chu, meanwhile, was offering scientific input to the response team.

And it’s likely that Perry’s agency will have a radically different feel to it, too.

The head of DOE can’t change the agency’s programs unilaterally, but Perry can try to convince Congress to tweak the budget and reorient energy priorities. And Republicans in Congress seem happy to oblige — back in 2013, the GOP House floated a draft appropriations bill that would cut the Energy Department’s spending on renewables and efficiency by half.

Perry’s long track record of climate denial is likely to cause concern among some agency staffers. Last week, a leaked memo revealed that the Trump transition team was asking for the names of any Energy Department staffers who had worked on climate change issues under Obama. Critics, like Sen. Edward Markey (D-MA), argued that this looked like a “modern-day political witch hunt.” The Obama administration has since said that it would refuse to hand these names over to Trump.

The leaked memo (PDF) also hinted at other possible Trump-era priorities for the Energy Department, like:

Reopening Yucca Mountain, the proposed waste repository for the nation’s commercial nuclear reactors that has been tied up under Obama over political concerns, particularly from Nevada. From the memo: “Are there any statutory restrictions to restarting the Yucca Mountain project?”

Helping the various nuclear reactors currently at risk of closing early due to competition with cheap natural gas. “What,” the memo asked, “can DOE do to help prevent premature closure of plants?”

Skepticism about DOE programs that support Obama’s Climate Action Plan, which Trump has said he would abandon. “Which programs within DOE,” the memo asks, “are essential to meeting the goals of President Obama's Climate Action Plan?”

Skepticism toward the DOE’s efficiency standards for appliances — which the Obama administration has been proactive about administering: “What is the statutory charge to the Department with respect to efficiency standards? Which products are subject to statutory requirements and which are discretionary to the Department?”

Some energy experts are holding out hope that Perry might still be convinced to support at least some types of low-carbon energy research while he’s there — such as carbon capture for coal or nuclear power — even if he does deny that climate change is a problem. These technologies, after all, tend to have support among conservatives.

On Tuesday, a massive new report by the Information Technology & Information Foundation outlined a variety of recommendations for future Department of Energy research that included everything from reorienting the national labs “to pursue commercially relevant RD&D” to investing in demonstration projects for advanced nuclear, solar, carbon capture, and “connected vehicles” technology.

I asked Teryn Norris, a co-author of the report and a former White House appointee to the Department of Energy under Obama, where he thought Perry might take the agency. His reply:

Governor Perry has a unique opportunity to build on the Department's blockbuster success in laying the foundations for the US fracking revolution by strengthening the agency's energy innovation programs, including critical technologies like advanced nuclear and carbon capture. If the Trump administration is serious about improving US competitiveness, surely they won't risk forfeiting these advanced energy industries and their multi-trillion dollar markets to China.

Further reading

— Here’s a look at how Trump’s pick for the EPA, Scott Pruitt, could reshape that agency.

— From earlier: Trump’s team is asking for the names of Energy Department employees who worked on climate issues