Honestly it would just be sad if most Steemians view this topic as "controversial"...
Sure, with regards to the extent governments can justify increased taxation on behaviours and consumption that contributes to pollution and/or use tax-payer dollars to subsidise green-energy solution is up for debate and I'm sure the large number of people here who prefer a small government have strong opinion on that. But as for whether or not climate change exists and that humans contributes to it, there really is no debate. You either understand the evidence for it or you don't.