Internationally renowned environmental campaigner Professor David Bellamy has joined the New Zealand group of scientists trying to refute what they believe are unfounded claims about man-made global warming.
Dr Bellamy, who joins scientists such as former MetService chief meteorologist Dr Augie Auer in the New Zealand Climate Science Coalition, was introduced to the group through a member in England.
The coalition has set down "seven pillars of climate wisdom" that include:
* Historically, conditions in many parts of the world have been warmer and cooler than they are now.
* A major driver of climate change is variability in solar effects, such as sunspot cycles, and not increased carbon dioxide.
* Global temperatures have not increased and a projection of solar cycles suggest cooling could set in and continue to about 2030.
* Stories of impending climate disaster are based almost entirely on global climate models.
Dr Bellamy said: "I look forward to working with the New Zealanders to create an international coalition to serve as a united voice for the many scientists around the world who believe climate science is not settled, that the world is not on the brink of a man-made global warming catastrophe and that we have much more to learn about this planet of ours that has been through and survived many natural upheavals and climatic cycles."
In 2004, Dr Bellamy described man-made global warming as "poppycock" then asserted last year that a large percentage of the world's glaciers were advancing, not retreating, but later admitted the figures were wrong.
NIWA climate scientist Brett Mullan, who is also a member of the Royal Society's New Zealand Climate Committee, said the coalition's refusal to believe in man-made global warming was a "frustration".
"I am disappointed. We point them to the evidence and they just don't seem to wish to accept it."
He said climate modelling had proven effective, such as in projecting temperature increases after the eruption of Mt Pinatubo in the Philippines in 1991.
Solar activity, monitored over the past 30 years, did not account for the climate changes being experienced now.
Temperatures varied from year to year, with the last peak in 1998, but overall temperatures were still much higher now than in the 1950s or 60s.
Dr Mullan said the world's top climate scientists had formed a consensus through the Intergovernmental Panel on Climate Change.
"We are seeing warming and it's caused by human activities."