Intrepid Science Blog

500 years of drought and flood: trees and corals reveal Australia's climate history Patrick Baker , University of Melbourne ; Chris Turney , UNSW Australia , and Jonathan Palmer , UNSW Australia Australia is the land of drought and flooding rains, and in a recent paper we’ve shown that’s been the case for more than 500 years. As part of our Australia and New Zealand Drought Atlas we’ve published the most detailed record of drought and wet periods (or “pluvials”) since 1500. The data reveal that despite the severity of the Millennium Drought, the five worst single years of drought happened before 1900. But 2011 was the wettest year in our 513-year record. The dominant theme of Australia’s drought history is variability. We may get one year of extremely wet conditions (for example in 2011) or we might get six years of extremely dry conditions (such as 2003-2009). North Queensland may be flooded out while Victoria suffers with drought. Or in extreme circumstances, the entir...

In Lewis Carroll’s wonderful book  Through the Looking Glass , Tweedledee emphatically declares to Alice: ‘Contrariwise: if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.’  It’s always a struggle to move beyond ‘contrariwise’. There’s a remarkable inertia in large institutions and industry to get the order of things right. Even when the need is a pressing one. Our planet is experiencing a frightening number of environmental crises. Extreme and abrupt climate change, biodiversity loss, soil degradation, ocean acidification and deteriorating water quality are just a few of the many important challenges we face on a worryingly large list.  But all are interconnected. Several years ago the United Nations Environment Program launched an ambitious target: for the world to develop a ‘ Green Economy ’, one which is low in carbon, efficient with resources and socially inclusive. By making the shift to a green economy an...

DNA evidence proves climate change killed off prehistoric megafauna Chris Turney , UNSW Australia and Alan Cooper Imagine a world populated by woolly mammoths, giant sloths and car-sized armadillos – 50,000 years ago more than 150 types of these mysterious large-bodied mammals roamed our planet. But by 10,000 years ago, two-thirds of them had disappeared. Since the end of the 19th century, scientists have puzzled over where these “megafauna” went. In 1796, the famous French palaeontologist Georges Cuvier suggested a global catastrophe had wiped them out. Others were appalled. The great Thomas Jefferson was so against Cuvier’s idea he sent an expedition to try to find vast herds of these animals grazing contentedly in the American interior. The only thing anyone could say with certainty was there should be a lot more of them than we see today. Alfred Wallace, who wrote the first paper on evolution by natural selection with Charles Darwin, noted that “we live in a zoologically ...