Any other ideas are absurd: we know the human contribution to climate change cause, have measured the anticipated effect, and found irrefutable causality.
Disputing human climate change is like disputing the surface temperature of the sun. These are measured facts, not theories.
What’s not conclusive is the doomsaying and specific claims about the future and present. A great example of this is California’s governor blaming forest fires on climate change, and another one is the signs predicting certain glaciers would melt.
In addition, science has not yet made a conclusion on the forest fires (the governor may well be proven right), and the Siberian feedback loop is a wildfire and was caused by climate change.
The governor ignorantly commented on an unknown. Deniers deny known facts. There is a huge difference.
That is impossible. Climate's a chaotic system, you can't back-predict the timing of droughts. And we already know that with or without human greenhouse gases, California has droughts. There is not some alternate history where California’s forest management practices wouldn't let these kinds of fires happen.