His manifesto confirms it:
That's exactly what is happening with the Anthropogenic Global Warming scam; too many people are too demoralised to assess true information about Socialism, Communism, and climate change to allow its use for other agendas on the hands of the useful idiots “the leftists” as former KGB agent Yuri Bezmenov calls them.
Enviro-communism is a new twisted idea of redistribution of wealth through “environmental” policies and the Copenhagen Climate Change Conference 2009 is the perfect manifestation of it. Environmental Justice is the new Social Justice; Climate Debt is the new Redistribution of Wealth, Anthropogenic Global Warming scam is the Communism.
How did he decide that global warming is a "scam"? Three guesses:
Climategate incident – exposing the eco-Marxist scam
On Thursday 19th November 2009 news began to circulate that hacked documents and communications from the University of East Anglia’s Hadley Climate Research Unit (aka CRU) had been published to the internet.
The information revealed how top scientists conspired to falsify data in the face of declining global temperatures in order to prop up the premise that man-made factors are driving climate change.
The documents and emails illustrated how prominent climatologists, affiliated with the UN’s International Panel on Climate Change, embarked on a venomous and coordinated campaign to ostracise climate skeptics and use their influence to keep dissenting reports from appearing in peer-reviewed journals, as well as using cronyism to avoid compliance with Freedom of Information Act requests.
Here follows a compendium of articles and videos on what was quickly dubbed as “ClimateGate”.
The full story:
 CLIMATE BOMBSHELL: Hacker leaks thousands of emails showing conspiracy to “hide” the real data on manmade climate change
 Climategate: the final nail in the coffin of ‘Anthropogenic Global Warming’?
Hiding the Decline:
 Hacked E Mails: Climate Scientists Discuss “Hiding Decline” In Temperatures  Mike’s Nature Trick  McIntyre: The deleted data from the “Hide the Decline” trick  Hide The Decline – Climategate
 Bishop Hill’s compendium of CRU email issues
Where did Breivik absorb this poisonous nonsense on his road to mass murder?
Please see Lord Christopher Monckton's speech
Oh. It would seem Monckton matters, even if serious people think he is a clown. Breivik took him seriously enough.