Method
Cold Nights
Fruit crops have critical lower temperature limits for growth and fruit quality. An air temperature < 6°C can have both positive impacts (e.g. induction of synthesis of red pigment in red fruit) and negative impacts (e.g. disruption of chilling accumulation; disruption of pollination, fruit set and growth processes; changes in pests and diseases). At temperatures ≤ 0°C, frost risk increases.
The number of days per annum when the minimum air temperature is below 6°C was calculated from daily temperature data. More detail is provided in the section Background: Climate Change Modelling.
The modelling for the intermediate future (2050s) was conducted using five different CMIP3 GCMs (Schulze, 2011).
Maps
Map Information
In the following maps, days < 6°C is presented under historical climatic conditions, under intermediate future climatic conditions (2050s), and as the projected change from the historical climatic conditions to the intermediate future climatic conditions (2050s).
Under the projections for the 2050s, the southern coastal regions are projected to experience a reduction of up to 20 days, while a reduction of more than 50 days is possible in the mountainous and high-lying interior regions.
The projected reduction in cold nights is likely to lead to a higher incidence of pests and diseases in spring, and a reduced risk of frost.