What tax investigators dubbed an "unprecedented" haul was salted away in tax havens in 2008 and 2009, so effectively hidden that 200 million euros has yet to be traced.
The scam, seen as a speciality of Franco-Israeli criminals, turned attempts to use market mechanisms to fight climate change against the taxman.
It involved buying carbon credits abroad and selling them in France with VAT added, but omitting to pay the VAT to the French tax authorities.
The godmother of the gang, former teacher Christiane Melgrani, was sentenced to nine years in prison and fined three million euros for fraud as part of a criminal enterprise, money laundering and criminal conspiracy.
Two other leaders, Gérard Chetrit and Eric Castiel, were sentenced to eight years in jail and a 10 million-euro fine and 10 years' jail and a 20 million-euro fine respectively.
Chetrit, who is in solitary confinement, took part in the trial by visioconference.
Castiel is still free and subject to an arrest warrant, as are seven other of the accused.
The 33 others received sentences ranging from a suspended jail term to six years in jail and a 200,000-euro fine.