Their stunning images of a fragile Earth seen from space helped start the global environmental movement, but, speaking at the Starmus science festival in Tenerife, astronauts Charlie Duke and Walter Cunningham declared that research into climate change is "bogus" and claim their photographs were exploited by environment campaigners.
According to today's Sunday Times, Duke, who took pictures of Earth aboard an Apollo 16 mission in 1972, and later became a Christian, told the conference: "Climate science is bogus. The world has got no warmer for more than 15 years. It is a great irony that the images taken on the Apollo mission have been used in this way. We helped to start it [the environmental movement] but I do not agree with it."
Walter Cunningham, who was aboard Apollo 7 in 1968, said: "Climate change is one of the greatest scientific fiascos of all time."
Cunningham is known for his doubts about anthropological global warming (AGW) having published a pamphlet in 2010 called Global Warming: Fact Versus Faith. The pamphlet was published by Heartland Institute, a conservative think tank which promotes skepticism about climate change.
The images of Earth seen from space are thought to have contributed to the birth of global environmental movements such as Friends of the Earth and Greenpeace.
Nasa is engaged in researching climate change. Its website states: "The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years."
Other speakers at the festival included Richard Dawkins, Stephen Hawking, and Queen guitarist Brian May, who is an astrophysicist.
There is no suggestion other guests at the festival shared the views of either Duke or Cunningham.