TEMPERATURES will continue to increase, southern and eastern Australia will face more bushfires and southern Australia will see an increase in droughts due to decreasing winter and spring rainfall.
On the surface, the 5th biennial report into the state of the Australian climate contains no new headlines, that in itself is terrifying.
First conducted in 2010, the reports have been consistent in attributing increasing greenhouse gases and carbon dioxide levels to the continued burning of fossil fuels.
They have also been consistent in reporting the increase in average temperatures and extreme weather events.
For our farmers, many of whom are still in drought, the report refers to long-term consequences of climate change during a period when, rightly or wrongly, the industry is focused on the short term and day to day implications of weather.
CSIRO, director of the Climate Science Centre, Dr Helen Cleugh said the report describes both the variability and long-term trends that have been observed of Australia’s climate, combining both the work of the Bureau and the CSIRO.
Dr Cleugh said the long-term warming trend reported in previous State of the Climate reports has continued.
“Australia is now warming by just over one degree Celsius since 1910 when records began,” she said.
“The warming trend is leading to an increase to the frequency of heat exchange and we are also seeing in the observations a long-term increase in extreme fire weather and length of the fire season.
“Our observations show the oceans around Australia are warming.”
Dr Cleugh said observations made at Cape Grim in Tasmania and compared with measurements of air bubbles trapped in Antarctic ice, continued to confirm rising levels of carbon dioxide in the atmosphere.
“Our observations of carbon dioxide show those levels have increased to levels we have not seen in at least 800,000 years,” she said.
“The measurements from Cape Grim have actually exceeded 400 parts per million (ppm) and are staying above 400ppm.”
Bureau of Meteorology, manager of climate monitoring, Dr Karl Braganza said while State of the Climate does not report on effective rainfall, the difference between the amount of rain and the amount lost to evaporation, the Bureau does track evaporation.
“Evaporation rates have been going up over many parts of the continent,” he said.
“It is quite sensitive to variability, but the combination of the higher temperatures and the lack of rainfall clearly combines to reduce the amount of water in the environment.
“What we have found in the drought we are currently experiencing, over winter and spring we had record breaking evaporation over parts of NSW and Qld.”
State of the Climate
- Australian temperatures will increase
- More hot days, fewer cold days
- Global temperatures rise continues
- Sea-level rise to continue
- Oceans warming continues
- Further acidification of oceans
- Tropical cyclones decrease in number, but increase in intensity
- Extreme rainfall events to be more intense
- More fire weather for southern and eastern Australia
- Decreased winter and spring rainfall for southern Australia
- Increase in droughts
Landing in hot water
Dr Cleugh said one of the new features in the state of the climate was the observation that warming ocean temperatures is resulting in longer and more frequent marine heatwaves.
“Warming oceans are expanding oceans, so we are continuing to see sea-levels rising globally and around Australia,” she said.
Dr Cleugh said the rising carbon dioxide levels are also increasing the concentration found in the oceans, leading to continued acidification.