History - AustralianAustralian CultureAustralian IdentityAustralian animalsCultural Comparisons Between Australia and other CountriesAustralian Prehistory


Australian Environmental Issues

Blue-tongue
A true-blue battler

Box jellyfish
How to avoid the stings and what to do if stung

Crocodile
So you wrestle crocs...

Dingo
Unfairly judged in killing off the thylacine?

Echidna
The wise little gnomes of Australia

Emu
Victors of the great Emu war

Flies
Shaping everything from how Australians speak to how they salute

Funnel Web spider
Yyou'll never leave your ugg boots outside

Kangaroo
Most herbivores don't grow a spine until they are the size of an elephant. Not so the roo.

Snakes
Kill less people than cows

Shark attack Australia
How to ensure you don't go by the name of Bob

Tasmanian Devil
The solution to mainland extinctions?

Tasmanian Tiger
A sad tale

Wombat
Keg of muscle

Quoll
The mainland's largest marsupial carnevore

Mythical creatures
Yowies and dropbears; some say they are myths but those who are not afraid to talk have shared their stories

 

 

Email

 

 

Uluru - What was and what could be

How Climate Change Might Affect Australia

Until 100,000 years ago, Australia was covered in rainforest. Could it be covered again?

Gum trees and red desert sand is synonymous with many international conceptions of Australia; however, it is the rainforest which has the longer association with the Australia landscape. Dating back more than 100 million years, some of Australia's rainforests are more than 10 times older than the Amazon and still contain ferns, conifers and angiosperms that once covered the Gondwana super continent. In 2002, the discovery of the remains of tree kangaroos in caves of Nullarbor Plain (now a desert) indicate that many of the rainforests lasted over central Australia through the Pliocene epoch (5.333 million to 2.58 million years ago) when global temperatures were 4 degrees hotter than industrial times. They continued to sometime in the last 100,000 years. The existence of leaf eating megafauna such as the Sthenurine Kangaroo and Diprotodon until around 50,000 years ago suggest plants other than the virtually inedible eucalypts were very common on the landscape until recently.

Australian megafauna

For tens of millions of years, the Australian continent had sufficient edible plants to support the evolution of huge Sthenurine Kangaroo and Diprotodon

Why the rainforests disappeared after tens of million of years of climatic variations poses questions about whether they could ever return in the era of global climate change that predicts increased temperatures but also more rainfall in certain areas.

There are two main explanations for why the rainforests retreated. The first is that the Earth gradually cooled due to changes of its orbit around the sun and/or changes in solar activity. As the Earth cooled, less rain fell on Australia and the rainforests became desert. The second theory proposes that humans were responsible for causing the collapse of the annual monsoon over central Australia. To clear forest for the animals they fed upon and to herd them towards spears, humans engaged in large scale burning of the landscape. Rainforest became savannah and then desert. After the foliage was razed to the ground, rain fell and soaked into the sand or quickly evaporated under the scorching sun. In turn, a reduction in humidity decreased the number of clouds forming. In a sense, prehistoric humans did over thousands of years what many South Americans are doing in decades as they turn rainforest into farms. As stated in the Future Eaters:

"Rainforests are killed by fire, but the Eucalypts had evolved in the fire prone areas, and they thrived on it. In an unholy alliance with fire, the eucalypts spread across the continent - destroying the original forests, creating the Australian landscape we know today.
I think the triumph of the eucalypts was to change, even the climate of the continent. The original forests had acted like a sponge - storing huge quantities of moisture, and transpiring it back into the atmosphere. This allowed the monsoon rains to penetrate hundreds of kilometres south. The rains fed a permanent river system, that flowed inland - filling the lakes at the heart of the continent." (2)

In 2004 and 2005, Dr John Magee and Dr Michael Gagana from the Australian National University argued that this burning caused a decrease in the exchange of water vapour between the biosphere and atmosphere. Clouds stopped forming and the annual monsoon over central Australia failed. Whereas once the Nullarbor Plain was home to forests and tree dwelling Kangaroos, now it is desert. Likewise, Lake Eyre, formerly a deep-water lake in Australia's interior, is now a huge salt flat occasionally covered by ephemeral floods. (1) (2)

Nullabor

The Nullarbor plain is now mostly desert, but when humans first arrived in Australia it was covered in forest and was home to tree-kangaroos. Potentially, it could be reforested.

Tarkine Rainforest

In Purnululu National Park, sandstone domes have provided some protection from fire, thus allowing rainforest to hold on where shrub and fire prone woodland has taken over elsewhere.

Exactly how an increase in global temperatures will affect this human modified landscape has been a source debate. Given that rainforests dominated when temperatures were up to 4 degrees hotter than now, then there is potential for rainforests to return. The potential variables would be changing ocean currents and changing vegetation. Given favourable vegetation and ocean currents, a hot climate should allow for rainforests to prosper.  

According to climate models relied upon by the CSIRO, global warming will result in northern Australia (which wants less rain) getting more rain while southern Australia (which wants more rain) will get less. The former Australian government's chief climate change expert, palaeontologist Tim Flannery, summed up the expected change by saying

"there will be more rain but the climate will be drier."

On the surface, there seems to be some doubt as to whether the models have been interpreted in an objective way and even more doubt as to whether the models are utilising the best possible variables when making their calculations. In regards to Tim Flannery’s conclusion that there will be more rain but it will be drier, a significant problem with his interpretation is that many of the rivers in southern Australia originate in northern Australia. Therefore, if there is more rain in the north, more water will flow south and potentially influence the climate of the south in the process. For example, Lake Eyre to the north of Adelaide is fed by rain falling in regional Queensland. In recent decades, Lake Eyre has been filling more than it has been over the subsequent century. Although this broadly supports the climate models' prediction of more rainfall, it doesn't support the interpretation that there will be less water for use in the south.

Murray Darling

Image 1 - Murray Darling Catchment. Rain that falls in the north will swell waterways that flow south.

Lake Eyre catchment

Image 2 - Lake Eyre catchment

Increased water flows into Australia’s rivers could potentially increase vegetation, which long term, could  increase rainfall and restart the annual monsoon over central Australia. For example, two Russian scientists, Victor Gorshkov and Anatassia Makerieva, have developed a theory known as the biotic pump (3), which they have used to help explain the failure of climate models to predict climatic events. The biotic pump proposes that condensation, not temperature, drives wind and in turn plays a major role in bringing more condensation to the drier interior of continents. Specifically, as condensation reduces air pressure, air is sucked from over oceans and brings even more rain thus creating a positive feedback loop.

The scientists predict that if Australia was reforested, a wetter climate would follow and perhaps increase rainfall by up to 90%. Potentially, increased rain in the north could increase the forests in the north and bring even more rain south and help reforest the south. This could increase the risk of flooding in the north, but would allay some of the fears about a lack of water and heat waves in the south, especially if more northern rivers were dammed and redirected away from Queensland’s urban areas. (It is unknown if vegetation changes have been factored into climate model predictions. It is unlikely though because the biotic pump is still just a theory.)

The theories of the Russian scientists are relatively compatible with the research of Dr John Magee and Dr Michael Gagana from the Australian National University who showed that deforestation caused massive climate change when humans first arrived in Australia. It is also consistent with observations of declining rainfalls and increasing forest fires in Brazil that have been attributed to the destruction of the Amazon rainforest to clear land for agriculture.

Even if the biotic pump is not the cause of wind or the drawing of moist air from the ocean (as some critics argue), it is almost universally accepted that forests recycle water and cause more rain. In a rainforest, 50 per cent of rainfall gets recycled by the ecosystem. Rain falls, is sucked up by trees, released into the atmosphere, reaches a critical humidity and then falls again at a different location. In short, large scale revegetation nourished by rain will cause more rain and thus expand the tree line. (This is the reason why the Amazon jungle covers most of South America). Additionally, rainfall will affect temperatures. An increase in cloud cover caused by forests transpiring water results in less sunlight reaching the earth. For example, in 2013, Australia endured its hottest month on record due to an absence of cloud cover over central Australia. 50,000 years ago, that area of central Australia had been covered with forest and would have had significant cloud cover.

In 2015, the Guardian newspaper ran a campaign that Australia could expect to 20 per cent longer droughts, more days characterised by severe fire danger, and a drop in rainfall by up to 69 per cent in southern Australia. (3) If true, such conditions would destroy the very viability of Australia as a country. Australia's food bowls in the south would collapse, towns would run out of water and bushfires would destroy whatever remained. Even small Pacific nations threatened by rising sea levels would have a brighter future.

Kevin Hennessy, a principal research scientist at the CSIRO, said the solution was to reduce CO2 emissions.(4) Many Australians believe they can achieve this by buying themselves a Tesla, or relocating their superannuation into funds with a focus on renewable energy. Unfortunately, even if every Australian bought a Tesla or the government made it compulsory for people to have solar panels on their roofs, given that Australia only contributes 1.07% to global emissions, such purchasing decisions won’t change rising temperatures even if they reduced Australia's emissions to 0. The argument is akin to fat people at risk of heart attacks saying their risk of death could be minimised if they had a diet coke with their Big Mac meal. It would be a good argument for McDonalds but it would do nothing for their obesity.

Admittedly, there is an argument that if Australia shows the way, the rest of the world, particularly China (which accounts for 27 per cent of global emissions and rising) will follow by also buying Teslas and putting solar panels on their roofs. Disregarding whether everyone driving Teslas will make a difference to rainfall and heat in Australia, history suggests that it is an argument that over states Australia's influence on the global stage. Just as Australia has tried to set an example for democracy that China hasn’t followed, Australia's has tried to set an agenda climate change that China has also chosen to ignore. In short, China doesn't care about Australian proselytising.

While most of the western world has stablised or reduced its CO2 emissions from 1970 to 2018, China has almost trippled its emissions from 2000 to 2018. As humbling as it may be, Australia doesn't have control of the global thermostat and China is not listening to Australians.

Even though Australia has virtually no power to alter global CO2 emissions, it does have power to influence whether a warmer world sees Australia turn to ash in bushfires or return to lush rainforest as it was in warmer epochs. In China, scientists have planted a great green wall of forests in its north (Three-North Shelter Forest Program) to stop the advancing Gobi desert. In Africa, scientists have planted a green wall to slow the advancing Sahara. Maybe Australians are like Chinese and Africans in that they don’t care how other cultures react to environmental threats. If the case were different, however, perhaps Australians could likewise consider planting great walls of trees. Not only would the tress stop the advance of Australia's deserts and take CO2 out of the atmosphere, the rainforests that endured for million of years across central Australia might return to endure as they have for so many tens of millions of years already.

1) Miller, Gifford & Fogel, Marilyn & Magee, J. & Gagan, Michael & Clarke, Simon & Johnson, Beverly. (2005). Ecosystem Collapse in Pleistocene Australia and a Human Role in Megafaunal Extinction. Science (New York, N.Y.). 309. 287-90. 10.1126/science.1111288. https://www.researchgate.net/publication/7741099_Ecosystem_Collapse_in_Pleistocene_Australia_and_a_Human_Role_in_Megafaunal_Extinction

2)Taming the Fire https://www.abc.net.au/science/future/ep1/trans1.htm

3)Hance, Jeremy New meteorological theory argues that the world’s forests are rainmakers Publish in Mongbay  1 February 2012http://news.mongabay.com/2012/0201-hance_interview_bioticpump.html

4)https://www.theguardian.com/environment/2015/jan/26/climate-change-will-hit-australia-harder-than-rest-of-world-study-shows

Invasive ferals

Carp

Carp and Trout
A tale of two ferals

New hope for Cane Toads
The many unknown predators of the toad

Rabbits
A fence almost 2,000 km long to keep rabbits out of WA? Sounds like a great idea! If it doesn't work, we'll build another one!

The Willow
How a change in its status from asset to weed led to fish kills with blackwater and blue-green algae outbreaks

To bait dingos?
Should the health of the ecosystem be considered or just the kennel club registration?

Koala control
What to do about the "koala plague" on Kangaroo Island

Cat
Apex predator in Australia. Confined to urban areas in America.

Environmental values

Environmental problems
How money and ideology shapes environmental "science."

Bushfire
Australia's Stockholm Syndrome with gum trees.

The Kangaroo industry
Should we eat skippy?

Climate change in Australia
Australia was once covered in rainforest. Could it be again?

Sustainability
The dark side of sustainable environmental policies

Native pets
Why no pet wombats?

 

 

       

Australian environmental science is defined by an ideology that is not unlike a prison warden. There, the scientists are not seeing themselves as part of the ecosystem, but as masters over it; protecting the rights of the species that they say have rights and killing those that they say do not…but inevitably killing both.

"It was always seen as desirable to remove or cull the introduced species. We also need to ask whether it was possible to do so, how it should be done, whether it could have unintended consequences and what it would cost? I don't think anyone really asked those questions." Physicist John Reid - 2012