here are a couple of excerpts from his Wiki Bio...
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According to an April 30, 2012 New York Times article,[71] "Dr. Lindzen ACCEPTS THE ELEMENTARY TENETS OF CLIMATE SCIENCE. He agrees that carbon dioxide is a greenhouse gas, calling people who dispute that point 'nutty.' He agrees that the level of it is rising because of human activity and that this should warm the climate." He also believes that decreasing tropical cirrus clouds in a warmer world will allow more longwave radiation to escape the atmosphere, counteracting the warming.[71] Lindzen first published this "iris" theory in 2001,[9] and offered more support in a 2009 paper.[51] (emphasis mine)
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Third-party characterizations of Lindzen[edit]
An April 30, 2012 article in The New York Times included the comments of several other experts. Christopher S. Bretherton, an atmospheric researcher at the University of Washington, said Lindzen is "feeding upon an audience that wants to hear a certain message, and wants to hear it put forth by people with enough scientific reputation that it can be sustained for a while, even if it's wrong science. I don't think it's intellectually honest at all." Kerry A. Emanuel, ANOTHER M.I.T. SCIENTIST, said of Lindzen's views "Even if there were no political implications, it just seems deeply unprofessional and irresponsible to look at this and say, 'We're sure it's not a problem.' It's a special kind of risk, because it's a risk to the collective civilization."[71] (emphasis mine)
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So, even Dr. Lindzen accepts the 'Elementary Tenets of Climate Science'...i.e. CO2 is a greenhouse gas, increasing in quantity due to human activity, and it is warming the planet...yet he refuses to postulate what constant increases and accumulation of CO2 would do to the global environment...pretty weak Climate Science IMO.
Link: https://en.wikipedia.org/wiki/Richard_Lindzen#Views_on_climate_change