This book is about the landcover change that has occurred in Australia over
the last twenty years. It presents the results of the Australian Case Study
for the International Space Year (ISY), 1992. The Case Study used satellite
data to detect, interpret and communicate changes in the landcover of the
Australian continent that have occurred during the last two decades.
This statement introduces an important characteristic of this book. Even
though this book was a team effort, one person (Dean Graetz) wrote this
text and did so in a personal and direct style. This is how I write because
this is how I am. The opinions that I offer here are mine, and mine alone,
I write this book as a concerned individual scientist. I am not presenting
the opinion of CSIRO. CSIRO does not have an opinion on the matters discussed
here.
The theme of the ISY was 'Mission to Planet Earth', and for good reason.
During the last two decades, many individuals and institutions had raised
their voices in concern over observations suggesting that all was not well
with the health of the planet. Problems of pollution, particularly atmospheric
pollution, had grown so large that national boundaries became irrelevant.
Acid rain, a by-product of the enormous amounts of coal burned in the industrial
areas of a few nations, had visibly influenced the forests and fresh water
lakes of most of Europe. The nuclear reactor disaster at Chernobyl in 1986
clearly showed that the innocent also suffer.
Moreover, it was not just the industrialised nations that were creating
problems. Degradation of previously pristine ecosystems by the expansion
of agriculture and forestry or through poor management of grazing animals
had become more frequently reported during the 1980s. In Africa, in particular,
the extent and severity of landscape change in the Sahelian region was so
great that the word 'desertification' became part of common usage. In South
and Central America, Equatorial Africa and in South East Asia the extent
and rapidity of deforestation of the tropical rainforests appalled those
observers who feared the short and long term consequences of unwise landuse,
not only for the nations directly involved but for the whole world.
Environmental problems were no longer national issues or even continental
in scope. They could involve the entire planet. Human activity had become
a global force.
