Dr Forrest made the comments at Fortescue's annual general meeting in Perth on Friday, also saying the company had made mistakes in its efforts to decarbonise but would continue to experiment.
The announcements come after the Western Australian company revealed record iron ore shipments at its annual results in August, but posted a lower than usual $5.2 billion profit due to falling commodity prices.
Fortescue also withdrew from two green hydrogen projects this year - in Gladstone, Queensland, and Arizona in the US - citing higher-than-expected costs to produce the renewable fuel.
But the company remained committed to achieving "real zero" by 2030 and investing in innovations such as green iron that would transform the world's steel market, Dr Forrest told shareholders.
Trend data showed renewable sources had taken over from coal-based energy generation during 2025, he said, proving fossil fuel producers no longer held a monopoly over the world's energy supply.
"You've got a president of the United States declaring that climate change is the great con job in history straight in the face of massive investment by some of the smartest people I will ever meet," Dr Forrest said.
"What's your independent authority say? (The) International Energy Agency is telling us by 2026 there'll be an unprecedented four million barrel per day glut in terminal oil demand."
Lobbying efforts by the US, Russia and Saudi Arabia to delay a vote on reducing maritime emissions also ignored "where the world is going" on energy generation and would be proven short-sighted, Dr Forrest said,.
Fortescue, which is Australia's third-largest mining company, has committed to removing fossil fuel from its iron ore operations by 2030.
Its 2040 goal includes producing green hydrogen to reduce emissions from its customers' production of steel.
Fortescue's Christmas Creek project in Western Australia is expected to begin green iron production later this year, even though producing the green hydrogen necessary for its creation had proven challenging.
The company would continue to experiment in renewable energy innovations to ensure it met its targets, Dr Forrest said.
"We're the guys out front with the arrows in the back, quick to be dragged down and quick to be told that we failed here, we failed there," he said.
"Failure is the fast track to success and decarbonisation is not a straight line - it demands creativity, experimentation and relentless innovation."
