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Impacts and opportunities
While the adverse impacts of climate change are evident, there may also be opportunities arising from a changing climate, for example, the growth of different crops and the development of new ways to produce renewable energy.
In addition, effective planning can bring about benefits such as improved water quality and better management of scarce resources. Taking action to reduce greenhouse gas emissions will also bring other benefits. For example, improved energy efficiency means lower power bills, insulated houses lead to warmer homes and less winter-related illnesses, and regularly-tuned cars improve air quality and health.
Energy
Warmer winters will put less pressure on electricity and heating supplies. Increasing rainfall in the Southern Alps could increase electricity supply because of higher levels in our major hydro lakes. However, smaller east coast hydro lakes may have less inflow, and in the summer more electricity may be needed for air conditioners.
Agriculture and forestry
Agricultural and forestry productivity may increase in some areas because of fewer frosts and the fertilising effect of elevated carbon dioxide concentrations in the atmosphere. A change in climate may also lead to the production of new commercial crops.
On the flipside, increased drought and other extreme weather events (such as storms and floods) will have a high financial cost, particularly in areas already affected by such events. Higher temperatures could also cause problems for crop production such as kiwifruit which require cold winters for fruit development.
More forest fires are also likely in drier eastern areas of the country.
Biosecurity and native species
Communities may enjoy the health benefits of warmer winters (and lower heating costs). However, hotter summers may increase the risk of heat stress. Sub-tropical diseases may also become a problem if carrier insects – such as mosquitoes carrying the Ross River virus – become established.
Rising average temperatures are likely to lead to the wider establishment and spread of new and/or existing “pest plants”, increased abundance of existing animal pests and greater survival of a range of insect pests.
Increasing temperatures are also likely to have an effect on our indigenous species, which are expected to respond by beginning to shift to more suitable climatic zones.
Water and rainfall
Snowlines are expected to retreat, changing water flows in associated rivers, particularly in the South Island.
Heavy rainfall is likely to put pressure on drainage and stormwater systems. Erosion and landslips from more frequent and intense rainfall as well as floods may increase road maintenance costs, but fewer snowfalls during winter could save such costs in some areas.
Infrastructure
More frequent extreme weather poses risks to major infrastructure such as buildings, roads, water, sewerage, electricity transmission and communication systems. Sea level rise and increases in storm surge, for example, are likely to endanger our coastal developments. However, costs can be avoided or reduced by factoring in climate change when routinely replacing or upgrading such infrastructure.
