May 17, 2012
Australia’s Warming Is Confirmed Using 1,000 Years Of Climate Data
Scientists in Australia have used 27 natural climate records to create the first large-scale temperature reconstruction for the region over the last 1000 years. This is the first study of its kind.
Researchers at the University of Melbourne led the study. They used a range of natural indicators including tree rings, corals and ice cores to study the temperatures in Australia over the past millennium and compared them to climate model simulations.
"The results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950", lead Researcher Dr Joelle Gergis from the University of Melbourne said.
"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.
The study will form the Australasian region's contribution to the 5th IPCC climate change assessment report chapter on past climate. The Study was published today in the Journal of Climate.
"Using what is known as 'palaeoclimate' or natural records, such as tree rings, corals and ice cores, are fundamental in evaluating regional and global climate variability over centuries before direct temperature records started in 1910", Gergis said.
Dr. Gergis examined these natural records provided by decades of work by more than 30 researchers from Australia, New Zealand and around the world .
The reconstruction was established using 27 natural climate records calculated in 3000 different ways to ensure that the results were robust.
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".
The study is part of a global collaboration, PAGES, Past Global Changes Regional 2K initiative, which is working to reconstruct the last 2000 years of climate across every region in the world in order to reduce uncertainties associated with future climate change projections.
Collaborators include the ARC Centre of Excellence for Climate System Science, Climate Change Research Centre and the University of New South Wales where the climate modeling was conducted.