evidence: How prevalent then were worries about global warming? An examination of peer-reviewed scientific literature conducted by a group of researchers in 2008, covering the mid-1960s through the 1970s, revealed that papers warning of global warming outnumbered those projecting cooling by a factor of six. So climate change in the form of global warming was a widespread topic of concern during this era, and there was no consensus that the Earth would cool in the immediate future. In later years, though, climate change deniers latched upon the 1970s speculations of a cooling planet as a way to discredit scientists who raise the alarm over increasing global temperatures. Some contrarians point to an international conspiracy they say is trying to suppress evidence of a supposed consensus on global cooling. Not only is global warming wrong, these deniers argue, but the exact opposite of warming may be happening — and in any case, how can we believe scientists who claim one thing in one decade and something completely different in another? Or who predicted one disaster that never happened, and now forecast another?