Assisted colonisation of Australian tortoise sets controversial precedent

From ScienceInsider, August 11, 2016 (Photo credit: Gerald Kuchling)

As long as it has been known to science, the diminutive western swamp tortoise has been in peril. By the time it was formally named in 1901—using a decades-old museum specimen—Pseudemydura umbrina was presumed extinct. And since it was rediscovered in the 1950s, biologists have struggled to protect it from the twin threats of habitat loss and introduced predators, which drove its numbers to bottom out at just 30 individuals in the 1980s. Now that climate change poses an even more urgent threat to the endangered tortoise, biologists have a controversial plan to safeguard its future—by moving it to new sites outside of its known historical range. The translocation, which took place today, makes the tortoise the first vertebrate to be deliberately relocated because of climate change. Read more…

Book review: The Sixth Extinction by Elizabeth Kolbert

sixth-extinction-e1396185506227There’s an old video clip that many Australians are familiar with. In black and white, the last known thylacine – or Tasmanian tiger – quietly paces about its caged enclosure, reclines in the sun, yawns at the camera.The footage was recorded in 1933 at the Beaumaris Zoo in Hobart, and serves as an eerie reminder of just how final extinction is.

In her latest book, The Sixth Extinction: An Unnatural History, American journalist Elizabeth Kolbert takes us on a global tour of extinction, in all its finality, as well as while it is happening before our eyes. The focus of the book is the latest, human-induced wave of destruction creeping around the globe, but Kolbert has widened her investigative lens to enlighten us about the processes behind extinction, as much as its victims. Disparate tales of species collapse are united by an unflinching exploration of the science – and the scientists – dedicated to understanding their demise. Continue reading “Book review: The Sixth Extinction by Elizabeth Kolbert”

Forecasting heat wave severity

Hot and bothered - heat wave hits Australia in January (Reproduced with the permission of the Bureau of Meteorology)
Hot and bothered – heat wave hits Australia in January (Reproduced with the permission of the Bureau of Meteorology)

Heat waves are a feature of the Australian summer and they claim more lives each year than other natural events — bushfires, floods, and storms — combined. As the climate continues to warm due to the effects of climate change, heat waves are set to become more frequent, and potentially more deadly. So it seems a little odd that we haven’t had an accurate way of forecasting whether a heat wave is on its way, and more importantly, how severe an imminent heat wave might be. The Australian Bureau of Meteorology  (BOM) is currently piloting a heat wave forecasting system that will do exactly this — I wrote about the science behind the forecast system for Science (subscription required).

The system uses gridded climate data — rather than temperature data taken from individual weather stations — to produce a high-resolution map of forecast temperatures across Australia. It then compares temperatures at each map point with previous temperatures recorded for that point and asks two important questions: are the next three days in the hottest 5% of days compared to the past 30 years? How do those hot days compare to the month preceding them? This second question is essentially an acclimatisation factor. If it’s been relatively mild in the lead up to a heat wave, it’s going to hit harder than if people are already acclimatised to the searing heat. The final step — adding a measure of severity — is achieved by comparing these 3-day events with all previous heat waves from the past 50 years. A severe heat wave is one in the top 15 percent of heat waves within this period (see map). Extreme heat waves are even rarer, but also likely to have a far greater impact. Head over to Science to read more.

A silver lining for the Great Barrier Reef

 

Cloud cover could protect the Great Barrier Reef from sea surface temperature rises.

An overcast sky is rarely a welcome sight for snorkelers on the Great Barrier Reef. But a generous cover of clouds could be exactly what’s needed for the future survival of the magnificent corals that make the reef the biodiversity wonder that it is.

The Great Barrier Reef hugs the north-eastern coastline of Australia across more than 2600 kilometres, earning it the distinction of being the world’s largest coral reef system. A considerable portion of the nearly 3000 individual reefs and 900 islands lies within the protected waters of a marine park, yet human impact is still keenly felt.

Global warming has seen consistently higher sea surface temperatures over the past 45 years. Continue reading “A silver lining for the Great Barrier Reef”

Reaping what we sow: Agriculture’s role in climate change

English: cow

Climate change usually evokes images of belching smokestacks and car-filled motorways. But if you’ve ever wondered what impact food production has on the Earth’s atmosphere, check out last Friday’s episode of Up Close:

Reaping what we sow: Agriculture’s role in climate change

The verdict: meat production is bad (and it’s as much due to urinating as it is to farting and belching), but crops aren’t without their own impacts. And once more, as long as the global population continues to increase – which it will – greater methane and nitrous oxide emissions in the future are guaranteed.