Fred Singer is one of the veteran climate change skeptics appearing at the Have Humans Changed the Climate? conference in Brussels hosted by Roger Helmer, a British Conservative Party representative in the European Parliament. Billed as speaking on the topic of "Why can’t we trust IPCC?" [Intergovernmental Panel on Climate Change], Singer staked out a position that even other sceptics disagree with. "We are certainly putting more carbon dioxide in the atmosphere. However there is no evidence that this high CO2 is making a detectable difference," he claimed. Singer, who has been a consultant to oil companies and the now defunct Global Climate Coalition, has also been a critic of regulatory restrictions on secondhand tobacco smoke. Ben Stewart of Greenpeace said that "conferences like this are designed to create confusion and play into the very understandable psychology of denial that most humans have ... This is what these people are relying on. Some are funded by fossil fuel companies so it is a very simple motivation, others have more complex reasons, but it does not change the fact they are wrong."