Global warming is theoretical. So is biological evolution one of the most advanced and quantified propositions in modern science.
The problem with theory is that people who are comfortable with ideology are able to dismiss theory as "just an idea." Theory is much more than that but the factually-conscientious cannot accept absolute terminology. They have to call it theory, because that is accurate.
Theory can be revised, refuted, supported, or discarded. That is consistent with an honest effort to describe reality.
The problem with ideology is that its proponents are globally powerful. And, here in the early 21st century, "global power" not only dominates the sea and land compared to other less-dominant species and cultures; but also affects the skies, the ecosystem the whole operation of livability on this unique planet.
The danger now is that ignorance yes, that is an accurate term is going to destroy the habitability of Earth for humans.
Ideologues and religious fundamentalists are more than insufferable. The pat answers and hardline policies of true-believers are dangerous and are incomplete even when they're not completely foolish.