Nobody is ever shut down. Even the Koch brothers have funded research intended to disprove the theory with no obstruction. Of course then that research ended up confirming it ! 
There was no '20 years of no warming'. That never happened. For 12 years (not 20) surface warming (not all warming) accelerated slower than predicted. It did not stop. It did not slow down. It did not even stop accelerating. It just accelerated slower than expected.
Can't deniers ever say a single true thing ? One true sentence to make the lies sound credible ?
Do you have to lie in every single sentence ?