Megadroughts In Australia

By Paul Homewood

 

 

With Australian drought a hot topic at the moment, it is worth revisiting this paper from 2014:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL062447

 

As studies have also found in California, severe droughts are nothing new for Australia. Evidence suggests that megadroughts have occurred in the last millennium, dwarfing any seen in the recent past.

There is a lot of technical stuff, but the concluding paragraphs tell the story:

 

The idea that climate never used to change until recently is something that was put to bed by HH Lamb half a century ago. Nevertheless so-called climate scientists still try to convince us otherwise.

 

And it is not just drought, but temperatures as well. The Little Ice Age was very real in Australasia as well as the rest of the world.

WUWT pulled together many strands of evidence of the MWP and LIA in Australia here.

However, the clearest evidence comes from New Zealand, where the Franz Joseph glacier expanded massively during the LIA.

 

Franz Joseph glacier

 

Historian Brian Fagan wrote in his book, The Little Ice Age:

“a mere pocket of ice on a frozen snowfield nine centuries ago”…. “Then Little Ice Age cooling began and the glacier thrust downslope into the valley below smashing into the great rain forests that flourished there, felling giant trees like matchsticks. By the early 18th Century, Franz Joseph’s face was within 3 km of the Pacific Ocean” .

“ The high tide of glacial advance at Franz Joseph came between the late 17th Century and early 19th Century, just as it did in the European Alps”.

It became so cold in New Zealand in those years that cold adapted penguins and sea lions moved north to the mainland:

A University of Otago-led study has discovered that the “Little Ice Age” is linked to dramatic shifts in Southern Hemisphere wildlife.

The international research team used ancient DNA and carbon dating to assess archaeological remains from New Zealand and sub-Antarctic coastal sites, while also exploring prehistoric climate signatures from across the Southern Hemisphere.

Study leader Professor Jon Waters, of Otago’s Department of Zoology, says researchers found a “very clear pattern”.

“Cold-adapted sub-Antarctic penguins and sea lions suddenly moved north to mainland New Zealand, right at the start of the Little Ice Age, around 1500 AD.

“One distinctive feature of our spectacular wildlife is how many species have arrived here only over recent centuries.

“This new research points to the role of climate change in redistributing species as conditions shift across the planet,” Professor Waters says.

Australian National University researcher Dr Ceridwen Fraser says there was a clear correlation between the downward spike in temperatures 500 years ago and the arrival of sub-Antarctic species.

“Interestingly, the Little Ice Age seems to have hit the Southern Hemisphere some 50 to 100 years later than the Northern Hemisphere.”

The human-driven extinction of mainland wildlife populations, and the subsequent sudden drop in temperature, is also thought to have decreased the human population of southern New Zealand, which in turn made the region more hospitable for new arrivals from the chilly south.

According to ancient DNA researcher Dr Nic Rawlence, of Otago’s Department of Zoology, the colder conditions “released human hunting pressure, creating opportunities for new species to arrive”.

https://www.scimex.org/newsfeed/little-ice-age-brought-penguins-and-sea-lions-to-nz-mainland

 

The increase in temperatures since the 19thC in the region needs to viewed from that wider perspective.