Climate change denial is a set of organized attempts to downplay, deny or dismiss the scientific consensus on the extent of global warming, its significance, and its connection to human behavior, especially for commercial or ideological reasons. Typically, these attempts take the rhetorical form of legitimate scientific debate, while not adhering to the actual principles of that debate. Climate change denial has been associated with the energy lobby, industry advocates and free market think tanks, often in the United States. Some commentators describe climate change denial as a particular form of denialism. Peter Christoff, writing in The Age (2007), said that climate change denial differs from skepticism, which is essential for good science. He went on to say that "almost two decades after the issue became one of global concern, the 'big' debate over climate change is over. There are now no credible scientific skeptics challenging the underlying scientific theory, or the broad projections, of climate change." The relationships between industry-funded denial and public climate change skepticism have at times been compared to earlier efforts by the tobacco industry to undermine what is now widely accepted scientific evidence relating to the dangers of secondhand smoke, or even linked as a direct continuation of these earlier financial relationships. Aside from private industry groups, climate change denial has also been alleged regarding the statements of elected officials. Between 2002 and 2010, conservative billionaires donated nearly $120m to more than 100 anti-climate groups casting doubt on the science behind climate change. In 1991 the New York Times reported that coal industry advocates were planning an advertising campaign which, according to their internal documents, was intended to "reposition global warming as theory rather than fact". More groups with similar goals formed, according to Newsweek magazine. In its August 2007 coverstory "The Truth About Denial", Newsweek reported that "this well-coordinated, well-funded campaign by contrarian scientists, free-market think tanks, and industry has created a paralyzing fog of doubt around climate change." The article described one group's plan was to "sow doubt about climate research just as cigarette makers had about smoking research". Newsweek subsequently published a piece by Robert J. Samuelson, who called the article "a vast oversimplification of a messy story" and "fundamentally misleading" because although global warming had already occurred, we "lack the technology" to unwind it, and the best we can hope to do is cut emissions. He argues that "journalists should resist the temptation to portray global warming as a morality tale... in which anyone who questions its gravity or proposed solutions may be ridiculed". The environmentalist writer and activist George Monbiot stated in his Guardian opinion column that he reserves the term for those who attempt to undermine scientific opinion on climate change due to financial interests. Monbiot often refers to a "denial industry." However, he and other writers have described others as climate change "deniers," including politicians and writers not claimed to be funded by industry groups. Mark Hoofnagle defines denialism as the employment of rhetorical arguments to give the appearance of legitimate debate where there is none, an approach that has the ultimate goal of rejecting a proposition on which a scientific consensus exists. In recent years the term has been associated with a series of views challenging the scientific consensus on issues including the health effects of smoking and the relationship between HIV and AIDS, along with climate change.