An ecologist who famously feuded with former Prime Minister Sir John Key has accused the current Government of not being "ballsy and strong enough" to restore the country's '100 percent pure' image.
Mike Joy of Victoria University's Institute for Governance and Policy Studies told The AM Show on Friday that, compared to when the tourism slogan debuted in 1999, we've had an 800 percent increase in the use of nitrate fertiliser, and 20 times the runoff in farming areas like Waikato and Canterbury.
And the effects have been devastating - Dr Joy said he could rattle off "numbers all night".
"Back in the '90s we had 22 percent of our native fish listed as threatened - now we have 74 percent," Dr Joy said. "It's just gone up - we're tracking to have no fish left in New Zealand if we keep going there."
Slogans like '100 percent pure' he says are obscuring the reality of "full-steam ahead" environmental decay.
"We need to be much more honest with ourselves. We're just kidding ourselves we're going to meet all these agreements and never do anything.
"Long before you start to get declines you have to put the brakes on - and we're not. We're not even close to putting the brakes on. Everything seems to be going full-steam ahead and we've all got our eyes shut and pretending it's going to be good."
Dr Joy made headlines in 2011 when he first publicly criticised the '100 percent pure' slogan. Despite his academic credentials, Sir John said Dr Joy was just giving his opinion.
"He's one academic, and like lawyers, I can provide you with another one that will give you a counterview," Sir John told the BBC.
As far as freshwater goes - Dr Joy's specialty area - he says the problem is being made worse by leaving freshwater decisions up to local councils, who don't want to drive industries away in case jobs go with them.
"The economy wins over everything, and the economy is measured by the wrong things - it doesn't measure the impacts. GDP only measures the good stuff, and we don't measure externalities.
"We always default to 'let's build it, let's do it' and we'll just worry about the problems in the future. We'll leave them for future generations. Twenty years of that."
Though there's no silver bullet, Dr Joy says there would be one thing we could do which would "fix a whole bunch of things" in one go - cut cow numbers by 20 percent, as recommended by the Parliamentary Commissioner for the Environment.
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This would reduce greenhouse gas emissions and force farmers to make money from the actual act of farming, rather than capital gains.
"Over most dairy farms in New Zealand you can get rid of 20 percent of the cows, so you get 20 percent of your methane emissions gone, make more money and have 50, 60 percent less freshwater pollution on those farms. The whole system's been cranked up the wrong way because farmers are profiting from capital gains and not from farming…
"There's heaps of evidence for this - make more money with less cows because you're not driving for capital gain, you're actually farming for profit."
Environment Minister David Parker has, in the past, said there won't be a cap on cow numbers, but reductions could be achieved through a nutrient runoff limit.
"We are determined to clean up our waterways," he told Newshub on Friday.
"This requires land use improvements. A blunt 20 percent cut in cow numbers is not being proposed. But limits on nutrient and livestock effluent pollution by catchment are being considered."
Dr Joy says the Government needs to act faster and heed the warnings from environmentalists like himself.
"I can't see anything ballsy and strong enough to even start to get us there. But I'm holding out hope, they're saying the right things - I hope they will do that. But it's a big risk for them, isn't it? If they get too ballsy then they get voted out, so it's very tricky situation."
Climate Change Minister James Shaw and Federated Farmers have been approached for comment.