Those who blame man for global warming have a set of beliefs concerning the cause and nature of global warming.
You might want to point out how the belief that man caused global warming is "concerning the cause, nature, and purpose of the universe, esp. when considered as the creation of a superhuman agency or agencies, usually involving devotional and ritual observances, and often containing a moral code governing the conduct of human affairs". Man-made global warming, simplified, is the idea that current human behavior is increasing the amount of solar heat retained by our atmosphere. That's physical science, not superhuman agency, devotional observance, or moral code.
Those believing in human caused global warming are clearly a group with a fundamental set of beliefs
You're using "fundamental beliefs" a bit too liberally here. There's a big difference between performing studies to see if a result has occurred and insisting on a notion despite any contrary evidence.
There is clearly a body of persons who adhere to the idea that man is causing global warming
And this makes it a religion? There's also clearly a body of persons who adhere to the idea that Cuba is 90 miles south of Miami, FL. Should I form the church and fill out the forms for tax-exemption?
Those who believe man is the cause of global warming clearly practice those beliefs and ritually observe that idea That man caused global warming is something some follow devotedly, as a point or matter of ethics or conscience.
"Ritual" implies far more than simply continuing to believe something. As for the ethics or conscience, that would be in response to what should be done about the portion of global-warming that is man-made, not whether man-made global warming is actually occurring. You have to separate the "how we shoudl respond" from the "whether it's happening".
Here's a point to ponder: these scientific whackos are claiming that human activity like burning fossil fuels and driving "more cars than the beach got sand" (Dave Matthews Band,
Too Much) and presenting their ritualistic "studies", "data", and other voodoo magic to back it up. The critical response is to deny, deny, deny, despite the evidence. Which side's being more religious? All of your definitions that you pulled from the dictionary can be easily turned around on those who insist that global warming
isn't affected by human behavior, and with a bit more merit, methinks.