Hot, dry Auckland summers, a wetter West Coast and plummeting frost-days await us if the latest climate change predictions come true.
The predictions were included in National Institute of Water and Atmospheric Research's latest climate change report, released yesterday.
It uses new data and draws on far more climate models than the previous report in 2004. It bases the predictions on the mid-range of expected ongoing greenhouse gas emissions, and draws its predictions out to the end of this century.
It states an unusually warm year today could be classed as very cold by the end of the century.
The expected 2C rise across the country is likely to coincide with a predominantly westerly wind, bringing more rain to the west and leaving less for the east.
Frost days have already fallen across the country, with 20 fewer frosts per year today in the Canterbury and Marlborough regions than there were in the 1970s. They could fall further, with the Central Plateau's 30-40 frost days expected to reduce to 5-15 days.
Auckland's hot days of 25C or more could triple from about 21 now to more than 60 - and that's only under a low-medium emission scenario.
Under a medium-high scenario there could be a staggering 80 or more days hotter than 25C. That's enough hot days for almost all three months of summer.
Rain is not so evenly distributed. Queenstown will have 12 per cent more rainfall each year, although most of that will fall over winter and spring. Tekapo and Hokitika are both expected to get an extra 8 per cent rainfall, and Invercargill is likely to get 7 per cent wetter.
A huge western chunk of the North Island, from Porirua to Port Waikato and stretching inland to Taupo, is also picked to get more rain. The rest of the North Island will get drier, especially Northland.
Niwa's Dr David Wratt said the evidence of climate change was mounting. The volume of ice in the Southern Alps had reduced almost 11 per cent in the past 30 years.
Prime to air another side of warming
Prime television is to air a controversial documentary arguing global warming is mostly caused by radiation from the sun.
The Great Global Warming Swindle attracted hundreds of complaints after it debuted on Britain's Channel 4 in March last year.
A few months later Australia's ABC network came under fire over its decision to show the documentary against the advice of its science journalist, Robyn Williams. Mr Williams was reported in the Australian newspaper saying it was "irresponsible" to air a programme that was "demonstrably wrong".
Critics argue the documentary is one-sided and misrepresents the weight of scientific evidence.
But supporters believe it is an answer to the popular award-winning documentary An Inconvenient Truth, made by former US Vice-President Al Gore.
AUT head of journalism Martin Hirst said Prime had added balance to the screening by scheduling a one-hour panel discussion on global warming straight after the film.
"If they were going to show just the documentary, you could ask why. Given the amount of coverage the documentary has had, Prime would be well aware of the controversy.
"If the audience is not given any insight into the controversy surrounding the claims made in the film, you could argue the audience is being misled."
Prime channel manager Karen Bieleski said the panel discussion featured representatives from both sides of the global warming debate.
But panel member Cindy Baxter, a Greenpeace climate consultant, said panel members had not had a chance to comment on the inaccuracies in the documentary.
"The debate was focused mainly on the scientific arguments. We didn't get an opportunity to talk about the makers of the film and the inaccuracies in it."
Scientists were quick to discredit the film after it screened in Britain and Australia. Two of the scientists featured in the film, Carl Wunsch and Eigil Friis-Christensen, have complained their contributions were misused.
* The Great Global Warming Swindle screens on Prime this Sunday at 8.30pm.
- Eloise Gibson