How might climate change affect my region? Climate change in Canterbury
Canterbury's climate is generally warm and dry in summer and cold in winter with frequent frosts.
A change in our climate as a result of global warming and other influences means we need to think about how we are going to plan for and manage the projected impacts of climate change in Canterbury and New Zealand. But we also need to take appropriate action to reduce our share of greenhouse gas emissions responsible for global warming and climate change impacts.
Some of the predicted impacts of a moderate rate of climate change for Canterbury include changes in average temperature, sea level rise and rainfall patterns. In general, the region will be warmer and drier in coastal areas. The Canterbury foothills and the Southern Alps are likely to be wetter and have more snowfalls.
Climate scientists estimate that Canterbury's temperature could be up to 2.5°C warmer over the next 70-100 years. This compares to a temperature increase in New Zealand during last century of about 0.7°C. To put this in perspective, the 1997/98 summer, which many New Zealanders remember as particularly long, hot and dry, was only about 0.9°C above New Zealand's average for the 1990s.
Coastal parts of Canterbury could be up to 20% drier while the foothills and the Southern Alps could be up to 25% wetter. The region as a whole is likely to experience more varied rainfall patterns and flooding could become up to four times as frequent by 2070.
The effects of climate change may bring significant costs to the community.
If extreme weather events become more frequent or severe, the costs and damages associated with them are also likely to increase. The cost of dealing with stock losses, replacing or repairing damaged roads, bridges, houses and stormwater drains, and dealing with increased soil erosion and loss of soil nutrients can be formidable. Recent extreme weather events such as the Marlborough and Canterbury droughts, Cyclone Bola, the "weather bomb" in the Waikato/Coromandel area, and coastal flooding during the Waitangi Day storm, have shown how vulnerable our society and economy is to the weather and climate.
There are likely to be benefits and opportunities from a change in climate too. Farmers could benefit from better crop growing conditions and faster growth of pasture but greater fertiliser use would probably be needed. There could also be opportunities to grow new crops, with a longer growing season and fewer frosts.
However, if the rate and magnitude of climate change is not slowed down, that is, if we don't reduce greenhouse gas emissions, any beneficial effects of climate change are expected to diminish and the adverse effects and long-term risks expected to increase.
Canterbury's climate
The climate of this region is greatly dependent on the lie of the massive Southern Alps to the west. Summer temperatures are warm, with highest temperatures occurring when hot dry foehn northwesterlies blow over the Alps and plains. Mean annual rainfall is low, and long dry spells can occur, especially in summer. For much of the time, summer temperatures are moderated by a cool northeasterly sea breeze. Typical summer daytime maximum air temperatures range from 18°C to 26°C, but may rise to more than 30°C. A temperature of 42°C has been recorded in Christchurch. Winters are cold with frequent frost. Typical winter daytime maximum air temperatures range from 7°C to 14°C. Northeasterlies prevail about the coast for much of the year. Southwesterlies are more frequent during winter.
Last updated: 20 March 2008
