Wednesday, September 12, 2012 • Shaan Te Kani
WITH the spread of the kiwifruit killer Psa disease now in the Coromandel, there is even more reason for agricultural communities to be aware of climate change.
The kiwifruit industry was one theme highlighted in a climate resilience workshop delivered by climate change expert Dr Gavin Kenny in Gisborne last month.
The aim of the workshop was to develop an understanding of what climate resilience means and how it might influence a business, the local environment and community, as well as what to do about the changing climate.
Dr Kenny said while there was plenty of uncertainty over climate change one thing people should anticipate was extreme weather events.
“There is evidence to suggest that the land area prone to drought is set to double and there would be more frequent and intense flood events,” he said.
For climate change and variability in Gisborne, Dr Kenny delivered statistics which said the district would be 0.9ºC warmer by 2040 and 2.1ºC warmer by 2090.
There would also be less rainfall on average — greatest decreases in winter and spring, but variations across all seasons.
Uncertainty also encouraged a “do-nothing” approach in many communities, he said.
But it was important to be proactive because climatic variability and extremes had a significant cost to the New Zealand economy as well as to the environment.
Flooding in Nelson last year cost around $16 million and Dr Kenny asked whether the Gisborne community was prepared because an event like Cyclone Bola in 1988 could easily happen again.
“Are we prepared?” he said.
“A minority are being proactive in planting trees, fencing waterways, protecting remnants of native forest, carrying out erosion control and drought fodder work.
“The majority argue that trees cost money and don’t make money — but what’s the cost of doing nothing?
“The proactive farmers argue for education not regulation.”
Dr Kenny said climate change impacts in Gisborne could have biosecurity effects such as the spread of new and existing pest plants, greater abundance of existing animal pests and greater survival of a range of insect pests.
Indigenous biodiversity effects could see shifts in suitable climate zones, strong impacts from increased weather extremes, changes to ecosystem productivity, and disruption to coastal and freshwater ecosystems.
Dr Kenny outlined the impacts that climate change could have on kiwifruit.
“More extreme weather events could mean less winter chill and warmer autumns, which could lead to challenges at harvest.
“Increased rainfall variability would see a need to protect water supplies near the coast from salt water intrusion, and a greater need for biosecurity from pests and diseases.
“A warmer spring and summer could be good for dry matter and a warmer climate and higher carbon dioxide would also be good,” he said.
The impacts on wine grapes could see changes in areas suitable for different varieties.
“There could be more rapid phenological development, a reduction in the optimum harvest window for high quality wines, water resource management would be affected as would climate variability and extremes.
“There may be changes in pest and disease pressure and effects from increased atmospheric carbon dioxide.”
The impacts on pastoral farming could see changes in pasture composition and increased prevalence of pests and diseases, said Dr Kenny.
It could also be more difficult to manage to the climate and new or increased animal health issues could arise.
One of the key factors was to understand vulnerability.
“What is at risk of being exposed and to what?” said Dr Kenny.
“What are the likely consequences and what capability exists to adapt to the consequences?”
Dr Kenny related these questions to a case study of a kiwifruit orchard in the Bay of Plenty.
“Exposure to income and livelihood arise from wind, hail, late frosts, warmer winters, pest and disease outbreaks.
“This results in a loss of productivity and income.”
Adaptive capacity would depend on individual circumstances and require a lot of technical support and know-how.
Adaptation and mitigation were key elements to climate resilience.
“Adaptation is what we do to respond to the anticipated effects of climate change,” he said.
“Mitigation is what we do to reduce or offset greenhouse gas emissions and a resilience approach can address both, and help address uncertainty.”
A buffering capacity could be built up by understanding natural cycles and preparedness for unpredictable events, having diversity and flexibility in agricultural management.
“Well-planned diversity can lead to an enhanced environment, biodiversity protection and enhancement, and reduced environmental externalities such as water quality, greenhouse gases, flooding and erosion.
“It can also create stronger communities, greater income stability and reduced impacts from climate extremes and pests and diseases.”