I propose we stop using the term "denier."
A denier is somebody who simply rejects something; holds the position that it didn't happen or isn't happening.
"Climate deniers" actively invent an alternative reality, invoking conspiracy theories, not unlike 9/11 Truthers.
A better term: Climate Truther
There are strong parallels with 9/11 Truthers:
9/11 Truthers reject the official story, based on multiple investigations by expert teams
Climate Truthers reject the science that's based on mountains of research by expert teams
9/11 Truthers invoke fake experts - or fringe experts (like those in construction or engineering) willing to publicly dispute the official story
Climate Truthers invoke fake experts or fringe experts willing to publicly dispute the mainstream science
9/11 Truthers invoke massive conspiracies, rooted in money/power/etc., often contradicting themselves (the planes were holograms, the planes were missiles, it was thermite, etc)
Climate Truthers invoke massive conspiracies-- all the world's scientific institutions are colluding to fake data, because money/power/etc-- and often contradicting themselves (The data doesn't fit the models! The data is altered to fit the models!)
9/11 Truthers fail at providing any coherent alternative narrative. They cannot answer the question "what really happened?" in any meaningful form.
Climate Truthers fail at providing any coherent alternative description of what's happening to our climate. It's cooling, it's warming but it's natural, it's the sun, it's ocean cycles, it is literally anything except greenhouse gases.
This way, we clearly define who we're dealing with, and we don't soil the term "skeptic" which has a basis in legitimate critical thinking; and we don't simply dismiss them as "deniers" when in fact they are doing so much more than just denying.