JAMES RENWICK

Climate change detective

Perfume opened James Renwick’s mind to the power of deciphering science. An enthusiastic headmaster stood in front of his primary school class in the tiny Canterbury railway town of Springfield and popped the stopper of a scent bottle. Raise your hand when you smell it, he told the kids. A slow-mo Mexican wave travelled the classroom from front to back. ‘‘So what is the speed of smell?’’ the teacher asked.

‘‘I still think about that question today,’’ says Renwick, sitting in his professorial office at Victoria University, where the Nobel Peace Prize certificate for his contribution to the Intergovernmental Panel of Climate Change (IPCC) is proudly framed on the wall.

The question started a discussion about gases and Brownian motion, and set Renwick on a path to study maths and science, which led to him becoming New Zealand’s Mr Climate Change.

Like a conscientious climate scientist, Renwick takes public transport from his

Ka¯ piti Coast home to the university and back. We’re late for the 4.15pm train, but his 62-yearold knees won’t brook running.

He slings his bruised old brown leather jacket over one of his 14 trademark waistcoats, crafted by his wife Elizabeth. It’s a world map – just don’t look for New Zealand.

Renwick’s Twitter name is CubaRaglanGuy – a nod to the 2007 book dividing Kiwis into eight tribes. He was a 50/50 split between the free-spirit, mismatched furniture, beat-up stationwagon Raglan clan (he’s never been on a surfboard) and the hipster, alternative music Cuba St tribe (he rates himself New Zealand’s biggest David Bowie fan).

But it’s not his quirky persona that won him this year’s Prime Minister’s Science

Communication Prize. While scientists sometimes become scientists because they’re happier digging through data than interacting with humans, Renwick likes to talk and he’s good at it. When Rotary invites him to meetings, he goes. And when the climate deniers troll, he hits reply rather than block.

‘‘I try to politely engage in conversation, point out the science.’’

Often he’ll suggest chatting over coffee. That’s usually the end of it. ‘‘It’s never really about the science, the facts, the evidence. It’s about their own world view.’’

It’s a rush through the early commuter crowds to Wellington railway station. We arrive on the platform just as the train doors close. An official stares unsympathetically and the train chugs off without us.

It’s hard to escape the metaphor – we left too late and couldn’t make up lost time.

For 30 years, Renwick has been thinking, writing and talking about climate change, since writing the first report for the Ministry for the Environment about how climate change might affect New Zealand, in the 1990s. But in those three decades, the increase in carbon dioxide in the air has doubled.

‘‘It took 200 years to get to the first half and only 30 years for the second half,’’ he notes.

And still, the policy makers are dawdling, Renwick says. As a lead author on the fourth IPCC report, in 2007, he naively thought a fifth report wouldn’t be needed: ‘‘Job done, kind of thing. It was so obvious to me – what was going on and what had to happen.’’ Now, he’s writing the sixth report.

Last year’s special IPCC report announced that global CO2 emissions had to almost halve by 2030 and reduce to zero by 2050 to limit global warming to 1.5 degrees.

‘‘If the world is serious about 11⁄2 degrees, 2020 is the absolute last year we can see any increase in emissions,’’ Renwick says. ‘‘The corner has to be turned in the next year, and there just isn’t any sign of that.’’

That’s the goal of New Zealand’s Zero Carbon Bill, which will be backed by a new Climate Change Commission. But Renwick worries it’s moving too slowly, and lacks teeth. The commission’s recommendations are not enforceable, so compliance is at the government’s whim.

‘‘Every month that goes by it makes the problem harder. I am really concerned that the urgency is just not there. Sure, the commission is a good idea. Yes, it should have more power to force things to happen. But they really need to get on with it.’’

"You don’t have to be a carbon Jesus before you can talk about climate change."

It’s a 20-minute wait for the next train. It’s pre-peak hour, but its arrival meets a crush through the doors. Some stand in the aisles. The biggest growth in New Zealand’s emissions has come from transport. Better public transport, more freight on rail, and better incentives for electric cars need to be part of New Zealand’s emissions reduction plan, Renwick says. That and cutting coal use for energy and Fonterra factory boilers, plus strategies to reduce methane.

Renwick drives a petrol-powered car, though the next car he buys will be electric. He still eats meat (but less, and more chicken than red meat) and still flies to attend some international conferences and meetings.

‘‘People say you can’t talk about climate change unless you don’t drive a car, you never fly. I don’t believe that. You don’t have to be a carbon Jesus before you can talk about climate change.’’

High-profile scientists are often criticised for becoming advocates instead of objective observers. Renwick doesn’t call himself an advocate, though he does call for action.

‘‘I do say I think the Government should be doing more, faster. Only because that’s what the science says.’’

And he doesn’t believe his passion blinkers his scientific objectivity. He once got a

Marsden research grant to study why Antarctic sea ice was expanding rather than melting, as you would expect if the atmosphere was warming. It’s been reducing ever since. His two weeks on the great white continent in

2005 brought home the reality of climate change. ‘‘Just to go and see what it’s like, and think about what it might be like if things do go pear-shaped, that’s pretty sobering.’’

At Plimmerton, the train looks out on a quietly lapping sea. It looks benign, but further up the line, at Paeka¯ ka¯ riki, the encroaching ocean is forcing the surf club to shift inland.

Renwick’s house is about 6m above sea level, but several hundred metres inshore, so he’s not too worried about its future. But he is worried about everyone else’s.

He grew up wanting to be a fireman, a truck driver, a detective, then a spy (maybe he still is). Instead he became a climate detective.

Armed with a maths degree, he fell into meteorology, making forecasts that places like airports based critical decisions on. He moved into climate research at Niwa, where he’d put his contact details on press releases. And so he slowly became the voice of climate change in New Zealand.

He tries to stay positive, but sometimes the gloom weighs heavily. He takes heart in growing public activism like the school strike and Extinction Rebellion (though he worries their message is too extreme).

The train pulls in to Paraparaumu station as he finishes suggesting what people can do to help. Sure, insulate your house, make your next car electric, take public transport. But also talk – like he does, he says. Politicians follow the public mood – if your local MP got

300 letters demanding climate change action, they would take notice.

‘‘It’s not down to the individual to solve this problem, because it’s a global economy. We can’t do it just by ourselves. We’ve got to persuade governments and businesses to change.’’