Philippe Verdier's dismissal from France-2 comes a month before Paris hosts a UN conference aimed at the most ambitious worldwide agreement yet to limit global warming.
He announced the dismissal in an online video over the weekend in which he described it as an attack on media freedom.
France Televisions, which owns France-2, would not comment today. French media reported that the network said Verdier had violated ethical rules.
In an online video he released at the time, Verdier criticizes "complete hype on the climate" by scientists, politicians, business lobbies, environmental and religious groups.
"You are dramatizing things to underline your will to gather the world's powerful and defuse a pending cataclysm," he wrote to Hollande.
Most climate scientists agree that the planet's climate is changing largely because of human action. Though some public officials and a few climate scientists disagree, the world's scientific organizations say that changes such as increasingly extreme weather and rising sea levels are a result of the buildup of heat-trapping gases, especially carbon dioxide, from the burning of coal, oil and gas.
In his letter to Hollande, Verdier questions the president's sincerity in promising to help the environment and asks him to plant a tree in the Elysee Palace to prove his "green" credentials.
Similar issues have popped up with some television weathercasters in the United States.
Donald Wuebbles, a climate scientist at the University of Illinois, notes the difference between television weathercasters who look at daily weather and scientists who study long-term change in the atmosphere over periods of at least 20 to 30 years.
