Far-reaching study tabs greenhouse gas emissions as main culprit
By Summit Voice
SUMMIT COUNTY —Studying tree rings, ice cores and corals, a research team from the University of Melbourne identified the fingerprint of mankind in an unprecedented warming trend that’s unprecedented in the Earth’s recent history.
“Our study revealed that recent warming in a 1,000 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,” said lead researcher Dr. Joelle Gergis. There are no other warm periods in the last 1,000 years that match the warming experienced in Australasia since 1950, she said.
Gergis said using ‘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.
She collated these natural records provided by 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 3,000 different ways to ensure robust results.
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 Climate Change Research Centre and the ARC Centre of Excellence for Climate System Science, University of New South Wales where the climate modeling was conducted.
The study published today in the Journal of Climate will form the Australasian region’s contribution to the 5th IPCC climate change assessment report chapter on past climate.