Shortly before he was elected speaker of the Florida House of Representatives in 2006, Sen. Marco Rubio traveled across the state introducing himself to voters.
The listening tour offered the Florida Republican, then an up-and-coming state lawmaker from West Miami, an opportunity to raise his profile and burnish his policy credentials ahead of his ascension to the speakership.
At stops along the route, Rubio and a handful of state House members held brainstorming sessions with supporters on ways to make Florida run more smoothly.
While most politicians use such trips to develop connections for future campaigns, Rubio went a step further, distilling the experience into a short book titled "100 Innovative Ideas For Florida's Future" that laid out his priorities for energy and environmental policy, among other issues.
In the book, which Rubio used to guide his legislative agenda during his tenure as speaker between 2006 and 2008, he promoted sweeping energy efficiency measures, tax incentives for renewable energy, and programs for alternative-fuel vehicles to help reduce the state's dependence on imported oil.
"Hybrid vehicles are guaranteed to save Floridians money on gasoline while reducing emissions and helping to curb global warming. For these reasons alone, Florida should seek creative ways to entice its residents to purchase them," Rubio wrote.
The passage suggests clearly that back then, Rubio believed in addressing climate change on its own merits. But nearly a decade later, as Rubio prepares for his all-but-certain 2016 presidential campaign, he has replaced his early support for hybrids and solar power with far more conservative talking points.
"I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it," Rubio said in an appearance on ABC's "This Week" last May.
Rubio doubled down on his position earlier this year, voting against an amendment to the Keystone XL pipeline bill that would have put the Senate on record saying that climate change is real and significantly driven by human activity.
Current debates over Keystone and other contentious energy and climate issues cropped up years after Rubio's book came out in 2006. The book captures a particular moment in time in Florida before the recession set in and Barack Obama's presidential election triggered the rise of the tea party movement that helped turn Rubio into a senator and GOP star.
Nevertheless, it provides an important window into Rubio's thinking in the years before he began courting the conservative primary voters and donors who control the Republican presidential nomination sweepstakes.
Bullish on renewable energy
Back when Rubio was crisscrossing Florida on his listening tour in the mid-2000s, the state generated 86 percent of its electricity from fossil fuels, according to his book.
Rubio said experts believed that the demand for electricity in Florida would increase by 30 percent over 10 years, and the state's gasoline consumption was expected to go up by about 4.5 million gallons per day by 2016.
Looking at the trend lines, Rubio decided it was "critical" for the state to invest in renewable energy to diversify its power supply.
Florida should "strive to lead the nation in fostering the development and use of alternative energy sources," Rubio wrote.
Rubio acknowledged that doing so would require "major changes in energy technology and infrastructure," but he concluded that the disruption was worth it in order to ensure that the state had access to reliable and affordable energy in the future.
The lawmaker said that advancements in the solar and ethanol industries showed "great promise" and also praised the potential of wind, hydrogen power and other forms of alternative energy.
He also touted a 2006 state law that enhanced existing grants, tax credits and other government programs for the development of renewable energy. The bill also created the Florida Energy Commission, which was tasked with crafting a statewide energy policy.
As speaker, Rubio showed a willingness to work with Democrats on green issues like the Florida Everglades restoration project, said Steve Schale, the director of Obama's 2008 campaign in Florida.
"In the state Legislature, he was far more moderate than he is today on a lot of things, whether it was the environment or immigration," said Schale, who ran the Florida House Democratic Caucus when Rubio was speaker.
Rubio maintained solid relationships with the energy industry and environmental groups. It helped that NextEra Energy Resources Inc., the parent company of the state's leading utility, Florida Light & Power Co., is a major investor in wind and solar power.
"Marco was kind of exploring" renewable energy at the time, said Frank Jackalone, a top Sierra Club official in Florida. "There was a segment of the business community that was exploring this, too, and [Rubio] was making friendly overtures to the environmental community, as well."
Touting energy efficiency, conservation
Rubio's moderate green agenda didn't stop with renewables. In his book, he also touted energy efficiency and conservation plans modeled on federal programs run by U.S. EPA.
His suggestions included creating a program to help homeowners meet the state's energy efficiency standards, and a public fund that would award loans to counties, cities, and public hospitals and schools for efficiency upgrades.
Rubio also backed the idea of a "performance-based permitting program" run by the state -- and modeled on EPA's National Environmental Performance Track Program -- that would help businesses comply with environmental regulations.
On top of those proposals, Rubio suggested additional tax incentives to help homeowners pay for energy-efficient heating and lighting systems and "solar products," an apparent nod to residential solar installations.
In another reference to climate change, Rubio noted that "energy conservation benefits the consumer through lower utility bills, higher quality of life and a reduction in global warming."
All these years later, his 2006 tour across Florida and subsequent book remain a key part of the story Rubio tells about his rise through the state Legislature on his way to statewide and national prominence.
The book is mentioned in the biography on his Senate website, and Rubio has claimed in the past that 57 of the 100 ideas he championed have been passed into law, a figure that critics dispute.
Rubio's office did not respond to requests for comment, leaving others to argue over his evolving views on energy and climate change.
Some observers maintain that his shift to the right is overblown because he was never a strong supporter of climate change action to begin with.
"I'm not entirely convinced that he's moved dramatically to the right," said Michael Binder, an expert on Florida politics who teaches at the University of North Florida. "His skepticism of the evidence on climate change is kind of how he's always been."
David Mica, executive director of the Florida Petroleum Council, said Rubio has been "an all-of-the-above guy throughout his career. He's supported advances in renewables but also in domestic [fossil fuel] production."
Others argued that Rubio has backtracked from his previous positions -- and is ignoring the effects of climate-induced sea-level rise on his own hometown of Miami -- to focus on his presidential ambitious.
"He's crafting a position that is meant to win the support of business interests and climate change deniers," said Jackalone of the Sierra Club. "It's clearly politically motivated, and it shows that he's not trustworthy."