First of all climate change deniers is not accurate, I don't know anyone who denies that climates change on this planet, we just don't buy the bullshit that we are causing it and the way to fix it is to tax everyone to death.
Secondly the global warming crowd moves the goalposts constantly, if facts don't fit your models you simply change terminology. If the temperature is too hot, it's global warming, too cold it's global climate change, average temperatures are also proof of global warming or climate change.
The reality is the earf is not a stable environment and never has been one. It changes constantly and no amount of taxation will end it. All one has to do is compare the predictions to what actually happens and the predictions never match.