Reconstruction of Australia's last 1,000 years shows the last 50 years have been the warmest on record.

"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," study researcher Joelle Gergis , of the University of Melbourne, said in a statement.

The study is the first of its kind for the region, and to recreate the climate, scientists have used 27 natural climate records to reconstruct its temperature over the last 1000 years.

These climate records include tree rings, corals and ice cores, which are fundamental in evaluating regional and global climate variability over centuries before direct temperature records started in 1910. They've been collected over decades of work by more than 30 researchers from Australia, New Zealand and around the world.

The reconstruction was developed using 27 natural climate records calculated in 3000 different ways to ensure that the results were robust. These were compared to computer-based climate model simulations.

She said 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. Knowing more about past climate will help researchers plan and predict the future.

The data will be included in the 5th IPCC climate change assessment report chapter on past climate and was published today, May 17, in the Journal of Climate.