Down under climate messages get more strident

Southern ocean warming worries scientists, heatwaves terrify government

Australia’s government has warned that rising global temperatures already represent a health risk – one that’s going to get worse as the country records more heatwave days.

Saying that “climate change must be considered a health priority”, the federal government’s Climate Commission believes the increase in hot days over the last 50 years has already led to an increase in heat-related deaths.

While the “headline” numbers bandied about in the climate change debate, such as two or three degrees in the average temperature, don’t sound too bad, such changes are associated with a sharper increase in the number of dangerous days, where the mercury surpasses 35 degrees Celsius (95 degrees Fahrenheit).

By the end of the century, the commission predicts, the “top end” (where some cranks believe Australia should be building new cities) will have daytime average maxima over 35 degrees for ten months of the year.

According to a report in Scientific American, another worrying health impact can be seen in 2011’s sudden rise in the fatal Hendra virus, which spreads from bats to humans via horses.

The health warnings come as scientists working in the Southern Ocean, which is the entry point for about 40 percent of the carbon stored in the Earth’s oceans, is warming, becoming less salty and more acidic, and is suffering an increased carbon load.

In this interview, Dr Steve Rintoul of the Antarctic Climate and Ecosystems Cooperative Research Centre, says the fall in salinity in the Southern Ocean agrees with predictions of climate-driven rainfall patterns.

“The fact that the surface waters are getting fresher tells us that there’s more rainfall than there used to be,” he said. “So the Southern Ocean provides one of the clues but that’s already happening now.”

Rintoul's report, "Position Analysis: Climate Change and the Southern Ocean", is available here. ®

Sponsored: Today’s most dangerous security threats