Showing posts from 2017
How Antarctic ice melt can be a tipping point for the whole planet's climate Melting Antarctic ice can trigger effects on the other side of the globe. NASA/Jane PetersonChris Turney, UNSW; Jonathan Palmer, UNSW; Peter Kershaw, Monash University; Steven Phipps, University of Tasmania, and Zoë Thomas, UNSWMelting of Antarctica’s ice can trigger rapid warming on the other side of the planet, according to our new research which details how just such an abrupt climate event happened 30,000 years ago, in which the North Atlantic region warmed dramatically.This idea of “tipping points” in Earth’s system has had something of a bad rap ever since the 2004 blockbuster The Day After Tomorrow purportedly showed how melting polar ice can trigger all manner of global changes.But while the movie certainly exaggerated the speed and severity of abrupt climate change, we do know that many natural systems are vulnerable to being pushed into different modes of operation. The melting o…

The Tropics and the Furious Fifties

There’s an old sailor’s expression: “Below 40 degrees south there is no law, below 50 degrees south there is no God.” Since the sixteenth century, sailors have spoken in awe of the violent westerly winds and seas they experienced fighting their way across the Southern Ocean. With few landmasses to slow them down, the winds found across 40 degrees latitude often reach speeds of twenty-five knots—about 40 percent stronger than their northern hemisphere counterparts—earning them the title the “roaring forties.” As shipping pushed farther south, explorers realized that these winds form part of a vast storm belt that includes the “furious fifties” and “screaming sixties,” names more reminiscent of terrible rock bands than a major part of our planet’s circulation system. The early hunters and traders didn’t understand it at the time, but these winds are created by a procession of low-pressure systems carried east by the jet stream, a river of cold air hurtling and twisting round the Antarct…

Echoes of an ancient time in Australia

Exciting results published today in the international science journal Nature provide precious new insights into the arrival and movement of humans across Australia over a staggering 50,000 years. 
Sadly, many Aboriginal Australians no longer live where their ancestors had called home. So to better understand Australia’s history before the arrival of Europeans, a forward-thinking initiative called the Aboriginal Heritage Project was set up. Led by the University of Adelaide’s Australian Centre for Ancient DNA (ACAD) in partnership with the South Australian Museum and Aboriginal families and communities, the team – in which I was fortunate to play a small part – have uncovered some remarkable new findings. 
Headed by Alan Cooper and Ray Tobler, the ACAD group analysed over 100 hair samples collected with consent from Aboriginal people across the continent between the 1920s and 1970s. These samples were collected as part of a project where along with hair, detailed records of the individua…