Global Systems
- Changing Environments

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Predictions

Many computer models have been done predicting the future.  They vary greatly.
Some suggest results are:

• Oceans will not warm as much as the land
• Greatest change will be in the northern parts of the Northern Hemisphere
• Area of land covered in snow will decrease
• Number of heat waves and tropical cyclones will increase
• Rainfall will increase in areas towards the poles but will decrease in subtropical regions (eg Mediterranean and Queensland/NT)

Who will survive?

Some scientists suggest that past climate change has resulted in loss of species from the earth.

Belief is that climate change combined with human destruction of ecosystems has lead to a reduction in biodiversity .

Australia is quite a biodiverse country we have

• Many species are unique to Australia
• 85% of our terrestrial mammals
• 91% of our flowering plants
• 90% of our reptiles and frogs
• 50% of the marsupial population

Great Barrier Reef

Coral is sensitive to small changes in temperature.
1-1.5 degrees C above summer average can stress the coral.
Protists (unicellular, photosynthetic organisms) live symbiotically with the oral and provide nutrients and colour
Stressed coral expels Protists and lose their colour (bleaching).
Algae take over and the coral may not recover.
The food chain is affected

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Kakadu

Any changes in fire regimes or rising sea levels could affect the Kakadu.  Although a lot of Kakadu is fresh water a rising sea level would salinate some of the lower lying fresh water regions changing the ecology of the area.

Species on the Move

• Centrostephanus rogersi has been found to be migrating south to Tasmania

• Kookaburras are migrating higher in the alps and feeding on alpine skinks
• Swamp wallabies and red-necked wallabies are moving higher up into the alps and eating more of the alpine flora

Changing Sea Level

We have found that the sea levels in the past have oscillated.  In the past 7500years sea levels have risen about 5.8 metres . This is natural for interglacial warming period. If all the water on the ice caps melted the sea would rise 70 meters (this is not predicted). But coastal cities could be inundated by moderate sea level rises.