The record warm start to the year will be the new normal within the next few generations, scientists say.

The first six months of 2016 have been the warmest since records began, but these temperatures may soon seem on the cold side, climate scientist James Renwick says.

"We're going to see more and more of these record warm months and years and in 50 years' time this year's record warm might be normal or even cool. What we think of as warm now is going to be average in a generation or so."

Northerly wind flows had contributed to warmer temperatures and a milder autumn this year, but Dr Renwick said it was the backdrop of climate change combined with weather patterns that created the record temperatures.


His predictions were echoed in climate change projections released by the Ministry for the Environment yesterday, which found average temperatures in New Zealand were expected to rise by up to 1C by 2040 and by up to a further 2C in the 50 years after that.

The report also predicted the number of hot days would increase by 40 to 100 per cent by 2040, while the number of cold nights would decrease by 30 to 50 per cent.

Rainfall would decrease in the north and east of the North Island, but increase elsewhere. The number of dry days each year would increase, as would the intensity of droughts.

The country would have more anticyclones in summer, the report said, and stronger southwesterlies in the winter. Daily extreme winds would rise, especially in the east.

Urgent action was needed by the Government to cut carbon emissions by the levels agreed to in Paris last December, Dr Renwick said. Its post-2020 climate change target is to cut greenhouse gas emissions to 30 per cent below 2005 levels by 2030.

"Time is really running out if we're going to stop the warming at 2C. We've only got about 20 years to reduce the rates of carbon dioxide in the atmosphere. Every country in the world has to meet their target."

Trading in carbon credits wasn't good enough, Dr Renwick said, because it was not a problem any country could buy its way out of.

Yesterday, climate action group Generation Zero presented their own draft of a Zero Carbon Bill during a protest outside Parliament.


Calling the Government's targets "meaningless", spokeswoman Lisa McLaren said its bill was based on Britain's 2008 Climate Change Act.

Winter's warmer than usual start has already affected retail and recreation. Mt Ruapehu yesterday had to push back its slope openings, scheduled for this weekend. South Island skifields Mt Hutt and Treble Cone also delayed opening day.

For some farmers, the warmth has exacerbated a lingering drought.

Yesterday, the Government pledged an extra $88,000 to drought recovery co-ordination as the medium-scale drought classification was extended to the end of the year.

Primary Industries Minister Nathan Guy said it would mean the North Canterbury area had been in drought for nearly two years.

Retail NZ said sales of winter woollies were down, but that had been offset by more DIY spending.

The warmth has led to reports of a rise in the number of rats invading houses. Pest Management Services owner David McPhee, of Dunedin, said his company's rat control jobs were up by 50 per cent on the same time last year.

Climate Change Minister Paula Bennett said the Government was committed to carbon trading, but it could use other tools too.

"That's why we're investing a record amount in research to find effective ways to reduce agricultural emissions. We're also investing in public transport and promoting the uptake of electric vehicles ... There is still more to be done."