Climate change alters weather extremes. We expect to see more extreme hot days (30+ °C), longer periods of dry weather, and higher risk of flooding when rain occurs.
We’re already seeing these extremes and expect these to increase and become more severe. Rare and extreme floods called a ‘one in 100 year event’, which means it has a 1% chance of occurring in any given year, will occur three times more often in Rotorua by 2090*.
Based on how much greenhouse gas we think is going to be added to our atmosphere each year we can estimate our future climate and risks.
Heat
’Hot days’ are days hotter than 25 °C. Between 1986-2005 Rotorua averaged about 10 hot days a year, but is expected to increase to 30 – 72 days a year by 2090*.
Extremely hot days (30+ °C) are also expected to increase. Extremely hot days pose health risks and can cause difficulty growing things because soil moisture reduces.
Heat sensitive plants, insects and birds will struggle to survive and numbers will reduce. We will also see an increase in pest species migrating to this area, which could cause further issues for our natural environment due to competition with native species.
Horticulture
Some fruit and vegetables, need winter chilling so our horticultural industry may suffer with a reduction in cold days but other subtropical produce may grow better than currently. Warmer winters means pests like the Queensland fruit fly could become established in this area - which would be devastating for our horticulture industry.
Droughts
Droughts in Rotorua and the Bay of Plenty are expected to be more frequent and severe, affecting our natural environment, tourism based around this environment, and mahinga kai (food-gathering) practices. Species that live in water habitats, like wetlands, rivers and streams, will be affected if their habitats dry up. Droughts also put pressure on agriculture and forestry.
Wildfires
Wildfires in forest or scrubland will become more prevalent in hotter, drier weather and could destroy our forest industry, infrastructure, our mountain biking network, and homes. Fires reduce air quality which affects our vulnerable people.
Rainfall and flooding
An expected reduction in annual rainfall in Rotorua will be spread between increased rainfall in winter and autumn, and declining spring and summer rainfall*.
Extreme rainfall events are expected to increase in intensity and frequency, increasing the risk of flooding land, streams and rivers
Flooding can damage homes and infrastructure and is a risk to people’s health and safety. Rainfall events can also wash pollution into our waterways.
*Reference: Climate change projections and impacts for the Bay of Plenty Region