Stuff - Many ways for our crop growers to adapt to climate change

Written by Brent Clothier

OPINION: Our summers are getting hotter but winters are not getting colder - the last summer was the hottest ever on record. Climate change affects many aspects of our life, including what we eat. It will influence what is available at the supermarket, when we get our food, where it comes from, and how much we pay for it. 

Climate change presents challenges, as well as opportunities, to New Zealand's valuable horticultural production systems, but growers and scientists are not the only people with solutions to adapt to and combat these assured changes to our weather. 

Plant & Food Research scientists have conducted climate change modelling of the production of our three major crops ‒ apples, kiwifruit and wine grapes ‒ in key New Zealand growing regions under various scenarios. If the temperature continues to climb and extreme weather events become more frequent, they will push flowering and harvesting time forward, increase water needed in summer, and deprive some crops, such as the 'Hayward' green kiwifruit, of their necessary winter chilling. 

There are many ways for growers to adapt. They can implement tactical measures such as using overhead cover and sprinklers to cool down fruit to prevent sunburn, or storing rainwater from wet winters to carry over for irrigation in dry summers. In transformational cases, we may see relocation of the core production base to new regions and a shift of the production cycle of certain crops. 

If New Zealand growers were no longer able to supply certain crops domestically in our normal seasons, retailers would need to import more of these fruits and vegetables from other countries to fill the gap, meaning consumers might need to pay more for imported produce.

However, the future is not all gloomy. The new climate for New Zealand may well allow growers to grow crops that they were not able to grow in large quantities before. Given our existing supply-chain infrastructures, this could well benefit industries like citrus and avocado or crops that are not yet planted. 

On the strategic adaptation front, plant breeders and scientists are working hard to develop new varieties that are more suited for hotter climates, more tolerant to certain pests and diseases, use less water, or do not require as much winter chilling. We could see a move from existing popular varieties to new and exciting varieties that come with different tastes, new textures, vibrant colours or better nutrition profiles.

As a consumer, you too have a role in reducing the climate risk we will face. Incorporating more fruit and vegetables in your diet is one of the best things you can do. Horticultural production does not emit methane, a major greenhouse gas produced by ruminants such as cows. Orchard plants can also store carbon in their plant parts and in the deeper parts of the soil of their root zone.  This photosynthetic carbon capture and storage mechanism keeps greenhouse gases from escaping to the atmosphere.

Consumers should also expect a wider, more exciting range of protein sources in the future. Food innovation scientists are now developing plant-based foods that can serve as viable alternative protein sources to meat. These are not merely "meat substitutes" but novel, nutritious, and flavoursome foods. Think beyond hummus and frijoles. These plant-based foods could become our dinner staples.

If more consumers demand and pay more for tasty and nutritious plant-based products that are grown in a sustainable manner, supermarkets and growers will source and grow food with better environmental credentials to meet the evolving market needs. This will create a virtuous cycle. 

There are plenty of land resources and natural capital stocks in New Zealand that can be better utilised. Our $8.8 billion horticultural industries currently use just 120,000 hectares of land, a small fraction of the 2 million hectares that are suitable for horticultural production. Why hasn't this huge biophysical potential been realised? This is due to socio-economic, labour, infrastructural and cultural constraints. Should we overcome these limits and constraints and allow horticulture to play a bigger and more valuable role in our future economy, it will make a significant difference to our greenhouse gas emissions and bring us closer to meeting New Zealand's net-zero emissions goal by 2050. 

Better nutrition, better adaptation to climate change, and more profitable use of our fertile lands and waters are right at our fingertips if we all play our part.