Tree rings tell climate story

Endowment funding from ACTEW is helping one researcher extend his tree-ring study in Australia's alpine regions. The end result could be a comprehensive climate record stretching back hundreds of years - with some sobering lessons for the future. BY SIMON COUPER Humans have been keeping comprehensive scientific climate records for a few hundred years now, at most. The availability and reliability of meteorological information from the past is a geographic game, depending on where you are in the world and who has been paying attention. If you want to find hard data about things like average annual rainfall in Australia prior to the late 18th century - when Europeans arrived with their equipment and log books - then you need to think laterally. Or saw laterally, as is sometimes the case for Dr Matthew Brookhouse. Brookhouse is a scientist and lecturer in the Fenner School of Environment and Society at ANU. He's also a woodsman. For weeks at a time, the young researcher can be found striding through the high country of southeastern Australia, collecting alpine tree-ring samples to build up a climate record stretching back over the last 400 to 500 years. He?ll use them to look at the correlation between tree growth and environmental factors, such as snow quantity and ambient temperature. The relative distance between tree rings in the trunks of various trees shows the relationship between growth and environment. For this work, the iconic snow gum (Eucalyptus pauciflora) has proven to be a useful window to the past. 'It's funny, but snow gum turns out not to like snow,?