This year, Australia experienced one of its warmest and driest winters in over a hundred years of recorded weather. The warmth has affected more than just thermometers and weather enthusiasts, with everyone from farmers to electricity suppliers feeling the effects.
Hot days, cool nights
According to the Bureau of Meteorology, the average maximum daily temperature for the whole country during winter was 1.9 °C above average. Queensland, Western Australia and the Northern Territory especially felt the heat, with some days in Brisbane reaching 13 °C above the average. These winter heatwaves are not new, but the warmth was widespread and significant, with more than 90 per cent of Australia recording daytime maximum temperatures that are within the top 10 per cent of warmest winters on record. Of course snowfall and blizzards still occurred in the southern ranges — as expected in winter — but the unseasonal daytime warmth had wide-ranging impacts across the country.
The night time temperatures were less consistent, with warmer than average nights recorded in Queensland and parts of the Northern Territory and Western Australia, but cooler than average nights in other parts of Western Australia and in south-eastern Australia. Some regions broke 20-year records for minimum temperatures and some areas recorded their coldest night time temperature on record. The colder nights were most likely due to the low rainfall, with the lack of cloud cover and low humidity letting the daytime warmth dissipate into the clear sky.
Many farmers in northeast Australia struggled with the unseasonal warmth, which caused crops to mature early. Large volumes of fruit and vegetables flooded the market, with bargain prices for crops from Australia’s largest winter growing region. Unconfirmed reports of greengrocers selling tomatoes for one cent a kilo and broccoli for four cents a kilo have been published online, and grocers reported that produce prices have fallen by more than 50%. Current produce prices are so low some farmers have chosen to dig their crops in rather risk making a loss by paying for picking, packing and freight. One Queensland farmer is taking a different approach, opening his carrot farm to the public for a pick-your-own harvest.
The cool nights have also been a problem. Central-west New South Wales had 50 to 55 nights below zero, in contrast to the winter average of half a dozen. The combination of hot days and frosty nights has devastated some canola crops in western New South Wales. A northern NSW farmer had to build greenhouses over his leafy greens crop to protect them from the harsh conditions.
Meanwhile, Queensland’s avocado growers are looking at a bumper harvest, with the warm weather promoting early flowering and increased bee activity to pollinate flowers. However, as the warm winter continued the bees have started to suffer, with the unseasonal heat melting wax in the hives and the lack of rain causing flowers to produce less nectar. The spring honey crop is expected to be the lowest in a decade.
In addition to day time warmth, the past winter was also very dry for Australia; the 9th lowest for national rainfall in over 100 years of records. Western Australia, where grain farmers rely on wet winters for a successful harvest, has been particularly affected. Many parts of Western Australia have been in drought for some time, and the winter drought is also affecting cattle farmers in Queensland and sheep farmers in Tasmania.
The warm, dry winter has also increased the bushfire risk for this summer, with Brisbane, Sydney, Canberra, Melbourne and Adelaide all considered to have ‘above normal’ bushfire potential for summer 2017. The increase in fire potential is due to the dryness of leaf litter, fallen logs, shrubs and trees. Despite the dryness, municipal water storage is high, with dams across NSW at 80 to 90 per cent of capacity.
Taking the heat off electricity
Finally, the warm winter has also been noticed by the Australian Energy Market Operator. During May to August, Victoria experienced its second-lowest ever electricity demand for a three month period. The reasons given for this record were ‘mild winter conditions’ and higher than expected electricity generation from rooftop solar panels, due to the lack of cloud cover. Electricity demand in all other regions of the National Electricity Market was ‘relatively flat’ compared to the same period last year, again mostly due to the milder winter.
Is it climate change?
Scientists are reluctant to attribute any one weather event to climate change, preferring instead to speak of trends and probabilities. However, the Climate Council asserted that the warm winter just past was ‘was made 60 times more likely by climate change… such warm winters are virtually impossible in a world without climate change’. It went on to comment that warm periods during winter are occurring more often, and lasting longer. The Climate Council’s statement is backed up by the CSIRO, which has found that winter rainfall in southeast Australia has declined by 28 per cent since 1990; this trend has been found across 50 weather stations.