Berwick-upon-Tweed's Conservative MP has admitted she did not regard climate change to be a "particularly urgent issue" at the time she posted social media messages disputing the science behind global warming.
Anne-Marie Trevelyan, who is also International Trade Secretary, in messages said to have been sent between 2010 and 2012, tweeted that "global warming isn't actually happening" while labelling environmentalists "fanatics".
The Twitter posts were reportedly sent before she became an MP in 2015 but after she had stood for the Conservative Party at the previous general election in 2010.
But Ms Trevelyan, who was promoted by Prime Minister Boris Johnson in last month's Cabinet reshuffle, said she had since seen that there was a "changing set of weather patterns" and called for the UK to decarbonise its economy and shift to green energy sources.
Asked about her climate change comments by the PA news agency at a fringe event at the Tory conference in Manchester, Ms Trevelyan said: "I think I'm much like ordinary citizens.
"Ten, 12 years ago, I wasn't particularly focused on it - I was busy bringing up kids, running three businesses, living in Northumberland, dealing with the vagaries of normal life.
The former international development secretary admitted she had been on a "journey" after seeing first hand the weather changes and having the "terrifying" science explained to her.
"I'm really, in that sense, just a very ordinary person who has been on that journey of suddenly becoming much more aware because it is real," she said during an appearance at a Conservative Environment Network event on Monday.
"And does that make me somebody who wasn't paying attention? Absolutely."
Ms Trevelyan added: "The exponential curve that we talk about, and that I now understand much better, I can see.
"I've seen just like every other normal punter that actually there is a real and changing set of weather patterns.
"I'm no brilliant scientist, I don't understand the complexities. What I can see is the real impact."
Her comments come after the Prime Minister confirmed he was setting the target of having all UK electricity created via clean means by 2035, with renewable energy to play a much larger part in the country's power output.
The Government has already banned new petrol or diesel cars from being sold after 2030 as Britain looks to lead the way in encouraging global powerhouses to sign up to preventing global temperatures from rising beyond 1.5 degrees Celsius at the Cop26 climate summit in Glasgow next month.