On food and the future
Australian agriculture has always been unusual. Within 10 years of the arrival of the First Fleet it was producing a surplus, and it has done so ever since. Our population has remained so small compared with what we can produce that the prosperity of our farmers has always depended on what they can sell overseas. Most other countries grow their produce to feed and clothe their own people.
Mine tailings on the rocks
Unsightly heaps of rock waste and ponds of tailings are common sights at many of our metal mines. Years ago the public accepted them as part of the price of full employment and prosperity in the region, but now there is increasing pressure on the mining companies to do something about them.
What?s in Port Pirie’s vegetables?
Two years ago scientists from the Division of Soils investigated the effects that heavy-metal emissions from the Port Pirie lead smelter were having on the surrounding countryside. They found that the smelter had affected a large area, producing higher-than-normal levels of lead, cadmium, and zinc — both in the soils and in the vegetables and wheat grown in them. However, these abnormal levels were lower than the standards recommended by health authorities and did not constitute a health risk (see ECOS 7).
Prospects for solar air-conditioning
The most noticeable thing about solar energy is that we get more of it in the summer than we do at this time of year. Many Australian sunburnt skins will attest the fact next summer, as more than 1000 watts per square metre come pouring down on them from a clear blue sky. As well as the sunburn cream, all those watts conspire to bring out the fans, air-conditioners, swimming pools, and other accoutrements that go towards beating summer heat.
Why do cyclones start?
How cyclones start has always puzzled atmospheric physicists. They know the conditions needed — areas of high humidity with some rotation must be located over a warm sea, which must have a surface temperature of more than 25.5°C. But under these circumstances a cyclone may or may not develop. And having this information doesn't explain why that's so.
King Billy pines and the world?s carbon dioxide
We often hear that the carbon dioxide content of the atmosphere is increasing. Before 1880, so the story goes, the pre-industrial level remained constant at about 290 parts per million (p.p.m.). Now the level is about 330 p.p.m. Some people blame much of this increase on Man's burning of fossil fuels.
Cold-air ‘lakes’ in the Snowy
Up in the Snowy, open grasslands mixed in with the eucalypt woodlands give a varied and pleasant landscape. These grasslands are a common feature of the subalpine high country of New South Wales and Victoria.
Chipping away at wood wastes
To many conservationists,‘woodchips’ is a dirty word. For them it conjures up images of a once-forested landscape devastated by clear-felling. The hullabaloo about woodchips really started a few years ago, when companies began clear-felling eucalypts for export to Japanese pulp and paper mills. In fact, the practice had already been going on for many years, albeit on a smaller scale, to keep the local Australian paper industry supplied.
Firing our grass trees
Fire has been a natural phenomenon in the Australian bush for many thousands of years, so it is not surprising that a number of Australian plant species have become adapted to it.