I have already mentioned the irony of a failed politician attacking climate scientists, accusing them of treating science like a religion while declaring his own faith that:
“The world stopped getting warmer 17 years ago. That’s incontrovertible.”
(See “Incontrovertible” is it, Rodney? and Confusion and distortion – has global warming stopped?).
But another factor in this sordid little story was the way that Rodney Hide attempted to portray New Zealand climate scientist Dr James Renwick as a religious fundamentalist in his science. Basically he did this by misrepresenting Renwick – Hide told a porkie.
Hide claimed that Renwick “was in no doubt that man-made global warming was causing the summer drought” and went on to give this quote as “proof;”
” . . climate change, global warming. Put more greenhouse gases in the atmosphere and things warm up.” The host Corin Dann double-checks: “And you’re of no doubt of that?”
“Oh, no, no. There’s no other explanation that’s remotely plausible.”
Hide then went on to declare:
“That’s religious zealotry in action. Science is never that certain.”
Creating the impression that Renwick had “no doubt” that greenhouse gases were responsible for New Zealand’s recent extreme drought.
Problem is – at this stage of the interview the drought had not even been mentioned.
Here’s the transcript of the interview from its beginning to Hide’s quote:
CORIN DANN: Good morning, Dr Renwick. How are you?
DR JAMES RENWICK: Good morning, Corin. Very well.
CORIN: Listen, thanks for coming on the show. I know you’re literally just back off the plane this morning. Tell us what is happening to NZ’s climate. Paint us a picture of what’s going on.
JAMES: Well, like the rest of the globe, NZ’s climate is warming up gradually. Temperatures have risen by the best part of a degree in the last century, and they’re set to rise by two or three degrees or maybe even more over the course of the coming century.
CORIN And this isn’t some normal- What is this? Is this climate change at work?
JAMES Yeah, it is. Yeah, climate change, global warming. Put more greenhouse gases in the atmosphere and things warm up.
CORIN And you’re of no doubt of that.
JAMES Oh, no, no. There’s no other explanation that’s remotely plausible.
Full transcript available at: Lack of govt leadership on climate change – Renwick
Simply a clarification that New Zealand’s climate is part of the global climate and that greenhouse gases contribute to global warming. The New Zealand drought had not even been mentioned at this stage.
The informal confidence Dr Renwick expressed was consistent with the current understanding of the role of greenhouse gases in global warming – not, as Hide and fellow pseudosceptics and climate change deniers have claimed, that greenhouse gases were the direct cause of our recent drought. That claim was a complete misrepresentation, clearly motivated and knowingly dishonest as the perpetrators also had access to the transcript of the interview.
Should Renwick have any doubts on role of greenhouse gases?
Dr Renwick did display, informally, a high degree of confidence that greenhouse gases are contributing to climate change. But that is hardly surprising because that is the current understanding of most climate scientists. Consider what the Intergovernmental Panel on Climate Change has said.
The figure below shows the results of simulations of global temperature from 1900 to 2005. Figure a included all the natural and anthropogenic influences. The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950). The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).
Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.
So, climate scientist have considered both natural and anthropogenic influences. And they are unable to reproduce the global temperature changes since 1970 unless anthropogenic influences are included.
That is why the IPCC has concluded that there is a high probability (>90%) that human influences are contributing to the current observed global temperature increase.
Notice also that the experts talk about probabilities. It’s a complex field and things are rarely cut and dried. We are more certain about some influences than others. And the IPCC doesn’t hide this fact – far from it. It doesn’t make sweeping claims in the way that some of their opponents do.
I am sure Dr Renwick accepts this – his comment “Oh, no, no. There’s no other explanation that’s remotely plausible” is simply an informal recognition of that.
While on the role of greenhouse gases this short video provides some of the data supporting current scientific assessment – in this case not relying on computer models or the IPCC.
Was our recent drought caused by CO2?
Later in the interview Renwick did comment on our drought. Here’s the relevant section of the transcript:
JAMES: Well, no, I don’t think panicking is very helpful.
CORIN : But it feels like that with this drought, though, doesn’t it?
JAMES: It’s a pretty exceptional event, yeah. It’s probably the first time in 50 years that it’s been this dry over this much of the country. So, sure, it’s exceptional. You know, a farmer would only see this once in a working lifetime.
CORIN: But if we’ve only seen it once in 50 years, should we not be that worried? That suggests it’s not going to happen for another 50 years.
JAMES: Well, the way the climate’s changing, the likelihood is that summers will become drier, so what’s a one-in-50 year event now will be, say, one in 20, one-in-25 year event by the middle of the century. And in some parts of the country, it might be a one-in-five year event by the end of the century, which means the farming sector’s going to have to adapt to that. We’ve got time – it’s decades we’re talking about, and farmers are very adaptable, but things will have to change.
Again, I think Renwick was just informally conveying what seems to be the current scientific assessment of the role of global warming in extreme weather events, like New Zealand’s drought and US storms. This is that one can’t prove a direct link of atmospheric CO2 to single specific events. However, scientific analysis analysis suggests that such events will become more frequent as the planet warms.
As Dr Renwick expressed it - “what’s a one-in-50 year event now will be, say, one in 20, one-in-25 year event by the middle of the century.”
Given the informal nature of such interviews I think Dr Renwick presented the scientific assessment pretty accurately. But of course this won’t stop the pseudosceptics and climate change deniers. Most of these, and certainly Rodney Hide, have a ultraconservative political agenda. They commonly paint scientists as plotters and schemers, part of an evil world-wide conspiracy wanting to bring in a One World Government. And claiming scientists have manipulated global temperature records to create false evidence for fclimate change.
And, yes, despite the availability of the interview transcript local climate change pseudosceptics are still misrepresenting Dr Renwick’s statements. (see Hide sticks it to Renwick and Renowden a scaring warmist). They are studiously avoiding the transcript and instead interpreting reporter’s comments.
And, of course, sticking the boot in while they are at it.