As greenhouse gases increase, so do temperatures – both here in Canterbury/Waitaha, and around the world.
What’s more, continuing to release greenhouse gases into the atmosphere at our current rate will mean that average temperatures in Canterbury/Waitaha could be up to 1.5°C warmer by 2040, and up to 3.5°C warmer by 2090.
Temperature increases are likely to be even greater in the mountains and high country, where by 2090, if no action is taken, average spring and summer maximum temperatures could soar as much as 6°C higher than today’s average.
Small temperature increases make a big difference. With just a 0.5°C - 1.5°C increase, we’ll see impacts here in Canterbury/Waitaha, with many more hot and dry periods in spring and summer.
Rising temperatures trigger other changes too. Rainfall patterns and growing seasons shift, droughts and fires become more likely, and there will be less snow and fewer frosts.
While that might sound like we’ll get more beach or BBQ days, rising temperatures can be bad news for our water supply, plants, animals, and homes.
If we all make a real effort to cut emissions, it’s possible that we can limit warming in Canterbury/Waitaha beyond 2030.
Our traditionally seasonal climate in Canterbury helps control pests and diseases, both on land and in water. More hot days put our biodiversity and water quality at risk.
Animals can really suffer from the heat, affecting both their wellbeing and production. For example, heat stressed cows may produce less milk, meaning there’s less available for dairy products. This affects farmers’ yield and can drive up dairy prices for us all.
A longer, warmer growing season with fewer frosts could provide opportunities to grow new crops, such as different varieties of grapes in areas which were previously unsuitable.
Drought caused by longer periods of dry weather means less water to go around, with restrictions to supply becoming more common. That means there’s less for non-essential water use such as gardening or filling the paddling pool.
Long, dry periods place increased demands on agricultural irrigation to support plant growth. If water supply is limited, production will be affected, and prices of fruit, vegetables, meat and dairy products will likely increase. Warmer conditions can also make it harder to grow crops such as potatoes that prefer cooler growing conditions.
Rising temperatures affect water bodies and their inhabitants across our districts. Warmer water can have impacts on aquatic life by reducing the amount of dissolved oxygen available in the water, as well as increasing the frequency of algal blooms. Algal blooms affect mahinga kai as well as recreational fishing and swimming.
We’re lucky that so far, the world’s oceans have taken up a lot of the carbon dioxide we’ve produced. But this comes at a cost – our oceans are becoming more acidic, which affects marine life, making it harder for kaimoana to build their shells or skeletons.
Around our coasts, sea level rise is a key concern for our coastal communities. Average sea levels around Aotearoa have already risen by around 20 cm since 1900, and depending on the rate of ice melt in Greenland and Antarctica, sea levels could rise by a metre by the end of the century.
We have recently seen devastating fires in the Port Hills, Pukaki and Ōhau. More hot days make plants and trees very dry, turning them into fire hazards. Wildfires can wreak havoc with our farms, homes, animals, forests and put people’s lives at risk.
Hotter days affect people too – particularly our vulnerable younger and older generations, and those working outdoors.
Increased acidity can have a real impact on our aquaculture industry, of which more than 60 per cent is mussels. Shellfish are particularly vulnerable to increased ocean acidity, especially as they form their shells in their early and juvenile life stages.
Pāua, cockles, kuku, and kina are taonga species with hard shells that are valued for recreational and cultural reasons. All are vulnerable to increased ocean acidity.
Increasing storm frequency and intensity can all impact the growth cycle of kuku (green-lipped mussels).