"Don't the deniers have a right to free speech?

There's a difference between free speech and a campaign to deny the climate science with the goal of undermining international action on climate change.   However, there's also responsibility that goes with freedom of speech - which is based around honesty and transparency.  Freedom of speech does not apply to misinformation and propaganda."

Banning free speech for 'holocaust deniers' was a slippery slope. Greenpeace uses the same misleading word to try to ban freedom for climate change skeptics too. But climate change skeptics don't mostly complain about the attack on freedom of speech per se, they complain that the word 'denier' is misused when applied to themselves!

I found the link to Greenpeace on this climate skeptic site:

It contains another amusing example of logical inconsistency - whereas it champions freedom of speech when it comes to seeing both sides of the climate change issue, it throws in the case against the current ruler of Sudan, as if it were settled, complaining that Sudan is allowed to participate in the UN committee on global warming. Having rightly rubbished Greenpeace, the author of the piece relies on Amnesty International as an unquestioned fount of truth.