Humans may leave Austarlia because of drought Expires: 28 days

On Thu, 2 Jun 2005 16:57:26 +1000, "Mike OMalley"

Moose, you should not encourage anyone to come here. They might see how good it is (was?) and decide to stay....and the land cannot even support the present population.

Australia is about 80% dead flat and pretty dry. The east coast has a low but significant mountain range extending for 3000kms from north to south. In spite of heavy and ongoing clearing-logging-burning, the region still possesses substantial natural forest and national parks. The southern corner has snowfields that are larger than the whole of Switzerland. Much of the melt is stored and used for subsequent irrigation.

The western slopes of this range feature good soil and reliable winter-spring rains which enable high wheat and other agricultural production for at least part of the year.

Northern half of Australia lies in the tropics and experiences seasonal monsoon rainfall with very heavy falls during summer and autumn. It is virtually uninhabited and unproductive apart from beef cattle and sugar cane. Much of it is fairly flat making fresh water storage extremely difficult particularly because of huge crocodile infested, mangrove lined river systems.

There is a small amount of forest in the SW corner of Australia where moist air sweeps in from the southern ocean.

Whilst the continent has experienced frequent droughts in the past, this one is more severe than ever. The cities of Sydney and Perth are genuinely facing a life and rest situation as their water storage levels dwindle. Other inland towns are facing ruin. Average rainfall has been steadily dropping for the last twenty or so and no significant rain is forecast for the foreseeable future.

I have two plausible theories. The antarctic glaciers are melting and huge icebergs are floating north, cooling the southern ocean and reducing evaporation from it. At the same time, the atmosphere is warming through pollution and less sunlight is reaching the water surface. Conditions over the generally flat Australian landscape are becoming less conducive to the formation of rain. The second is that because dry soil is a poor conductor of electricity, the whole of dry Australia has become (negatively) charged (due to wind action) and this also operates against the formation of raindrops even when sufficient moisture DOES cross the country. Clearing of inland forests has accentuated the problem because the deep roots of trees previously acted as conductors which would dissipate that charge. So the drought is reinforcing itself.

Australia might become the first real victim of global warming.