TECHNICAL
GLOBAL WARMING RISKS AND OPPORTUNITIES final word
Mike Nichols
Flooded Motueka River, 17 July 2021
It is predicted that climate change will result in a significant warming of the environment, but more importantly the development of extreme weather conditions. This will mean that rainfall patterns in particular which can influence crops, will be seriously affected. This will apply worldwide and we are already seeing some of these weather phenomena, for example the extremely high temperatures this northern hemisphere summer in North America. And the drought and frosts recently in Brazil which will affect world coffee production (and therefore prices) for several years. New Zealand is not immune to these extreme weather happenings, but with modern technology it should be possible to overcome, and even make use of them to improve our production systems. Kiwifruit is currently the major horticultural export earner, and they are (as far as we are aware) very sensitive to environment. At one time it was considered that the crop could only be produced in a limited area near Te Puke, though this theory has now been completely debunked. 44 NZGROWER : APRIL 2022
Nevertheless, adequate winter chill is an important component of productivity and with the pending departure of Hi-cane, this could pose major problems for kiwifruit producers in the top half of the North Island, unless a satisfactory alternative is developed. Many of the other tree fruits also require significant winter chill to perform, particularly apricots, nectarines and peaches, and even apple buds will fail to break evenly in the spring if they are inadequately chilled.
New Zealand is not immune to these extreme weather happenings, but with modern technology it should be possible to overcome Some 30 years ago a group of senior New Zealand agricultural scientists predicted that a major effect of global warming for New Zealand would be that the West Coast of both islands would have higher rainfalls, while the East Coast would receive lower rainfalls.
