Scientists say climate records from Australasia show there are no other warm periods in the last 1,000 years that match the warming experienced since 1950. A study led by researchers at the University of Melbourne used a range of natural indicators including tree rings, corals and ice cores to study Australasian temperatures over the past millennium and compare them to climate model simulations. \"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,\" researcher Joelle Gergis said Wednesday in a release. Using natural records such as tree rings, corals and ice cores is fundamental in evaluating regional and global climate variability over centuries before direct temperature records began to be kept in 1910, she said. Australasia is the geographic region consisting of Australia, New Zealand, New Guinea and neighboring islands in the Pacific Ocean. Records provided by decades of work by more than 30 researchers from Australia, New Zealand and around the world were collated to provide data for the study. The records not only provide a climate picture of the past but are also a significant platform to reduce uncertainties associated with future climate variability, Gergis said. The study published in the Journal of Climate is part of a global collaboration working to reconstruct the last 2,000 years of climate across every region in the world.