The Opposition Liberals have removed an MLA from caucus after he retweeted comments questioning the role of carbon dioxide in climate change.

The Opposition Liberals have removed an MLA from caucus after he retweeted comments questioning the role of carbon dioxide in climate change.

Party leader Kevin Falcon said in a statement that John Rustad has been removed for what he calls a "pattern of behavior'' that isn't supportive of the caucus.

The original tweet said the case for carbon dioxide being climate's "control knob'' was "getting weaker by the day.

The tweet included the hashtag ``Celebrate CO2.''

The party says while it encourages a diversity of perspectives, these have to exist on a foundation of mutual respect and trust, which it says Rustad had breached.