He said the experience of watching investment push bills up in the UK and Europe was making messaging coming out of the US more politically attractive to some.
He pointed to US President Donald Trump's speech to the United Nations last month in which he denied climate change, calling it the "greatest con job ever perpetrated on the world", and refuted the use of renewable energy.
"I mean, it influences a lot of people in the world," said Mr Evangelos. "So you may start to see, like we're seeing in Europe, especially, right wing parties to start blocking more and more measures for the energy transition."
The answer, he argues, is having a more honest debate.
"We have to measure the needs of the societies and the means of achieving our goal, what we have, and how do we get there?" he said.
He said a debate on energy transition had never happened on a grand scale.
"Let's sit down. How much money we have, how much of that can we spend on infrastructure?" he said. "And let's go out and explain to the people, unless we do that, we are not going to have them on board, and there will be more and more resistance."
He seemed confident that the UK and EU could come to a deal over steel tariffs.
To protect EU steel makers, the bloc is proposing a 50% tariff from June next year on all imports from the rest of the world - including the UK.
He said co-operation in areas like defence had sweetened the relationship.
"My take from Brussels is the climate towards the UK is much friendlier than it was three, four or five years ago. The fact that the UK is very willing to support Europe on the defence side - I think the climate is much warmer now to make a deal on these issues".