 O'Neill has opposed the tackling of global warming through reductions in carbon emissions and instead advocates for "technological progress" to deal with the damage done by climate change.He criticised the environmentalist activist Greta Thunberg in his 2019 article "The Cult of Greta Thunberg" in which he describes her as a "millenarian weirdo" and criticises the allegedly "monotone voice" speech patterns of the Swedish environmentalist who speaks English as a second language.In his 2012 "Huffington Post" article titled "If You Were Abused By Jimmy Savile, Maybe You Should Keep It to Yourself", O'Neill argued against victims of sexual abuse by high-profile individuals (such as Jimmy Savile) coming forward publicly, stating