Stronger winter winds, heavier rainfall and more droughts are predicted for New Zealand as the effects of climate change become more entrenched over the next 40 years.
A report by the Government's chief scientist released on Friday examines the effect of the changes on the economy and environment.
Sir Peter Gluckman says there will be an increase in the frequency of floods and droughts and sea level will continue to rise by 3mm a year leading to more coastal flooding and erosion.
His report says oceans are also warming and becoming more acidic.
Greenhouse gases will continue to accumulate in the atmosphere and there will be an average temperature increase of 0.9°C by 2040.
Sir Peter warns the country can expect more record high temperatures, Auckland will have 61 days a year above 25°C by the turn of the century compared to about 21 days a year now.
He told Radio New Zealand's Morning Report programme planning for the impact of climate change on infrastructure and farming should start now.
"Climate change is going to have a lot of uncertain but highly probable effects on different regions of New Zealand in ways which will fundamentally affect our economy."
The report does not suggest what should be done to tackle climate change, but notes changes in wind patterns, rainfall and ocean chemistry will have a big impact on many primary industries. It says there will be a drop in the number of frosts, leading to increased survival rates for pests.