Lead researcher, Dr Joelle Gergis from the University of Melbourne said the results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950. This period far exceeded the magnitude of warning in the so-called "Medieval Warming" period of 1238 - 1267.
"Our study revealed that recent warming in a 1000 year context is highly unusual and cannot be explained by natural factors alone, suggesting a strong influence of human-caused climate change in the Australasian region," she said.
She also noted that reconstructions of regional temperature not only provide a climate picture of the past but also a significant platform to reduce uncertainties associated with future climate variability.
According to the research team, the climate reconstruction was developed using 27 natural climate records calculated in 3000 different ways to ensure the robustness of the conclusions.
Gergis also said "We could not explain the 20th century warming by natural variability alone, suggesting a strong influence of greenhouse gases in the Australasian region."
A PDF of the paper published in the Journal of Climate is available here for a fee.
The research will form the region's submission to the 5th IPCC climate change assessment report chapter on past climate due to be published toward the end of 2014.