Did you know that Australia was the driest inhabited continent in the world? How ironic is it then that in the past 20 years, Aussies have been experiencing quiet a lot of rain? In fact, in some places it rained more than at any time in the past 200 hundred years! But how do we know how much it rained in the early 1800s? At that time the Brits had barely just started colonizing the continent! They definitely didn’t bother setting up rain gauges!
The answers come from the trees! By taking a core from old native trees and carefully studying the annual tree rings, scientists can work out how much it rained in 1802! What’s more important, though, is that the last two decades turn out to be unusually wet compared to the previous two centuries. In the one hundred and ninety years from 1800 to 1990 there were only two years when it rained more than 20 inches. By contrast, in four out of the past 20 years alone, it rained that much (and more). What is causing this?