Guy McPherson is nothing, if not controversial. His human extinction within 10 years prediction polarises people. And attracts large numbers of detractors.
Which is a shame.
Because, fundamentally, what the visiting Arizona University professor emeritus - who will give a talk at 6pm on Thursday at Whanganui's Davis Lecture Theatre - is saying, is correct.
Climate science is a murky area to say the least. Not all scientists speak with one voice nor is everything said and written about it to be believed.
Corporate and political interests are claimed to be behind the myriad of internet trolls who stalk well-known science websites and leave pseudo-scientific evidence to deny that
climate change exists.
Even the oil giants recognise climate change as a threat to human survival and acknowledge so on their corporate websites.
The United Nations, the science community, even governments in their dazed-in-the-headlights way acknowledge that mankind's polluting of the planet means we are in for challenging times as the ice melts and oceans rise, and the planet continues setting new benchmarks for being the warmest on record.
But what effect does a man, who claims hope is futile and that nothing can be done to save our species, have on such a crucial issue?
Some fear that the extremeness of his prediction of human extinction within 10 years acts only as fuel for the climate deniers out there - of which there are far too many.
Climate change is real. It does threaten every species and plant on the planet. We need messages that turn people on to the issue and not against it.
For Prof McPherson's part he says he is only reporting what he sees and he can hardly be blamed for that. But one wonders why he chose the maverick route, rather than concentrating on peer reviewed work and working with the science community.
For that reason, he will, unfortunately, remain controversial and, sadly, counter-effective.