1 
GLOBAL AND ENVIRONMENTAL MONITORING: 
TECHNOLOGICAL CONSIDERATIONS* 
by 
John S. MacDonald 
MacDonald Dettwiler 
Richmond, B.C., Canada 
ABSTRACT 
Achieving the goal of sustainable economic development requires that we 
manage our development of the earth's resources and our related impact on its 
environment in a way which provides economic growth while at the same time 
preserving the ecological equilibrium which sustains us. This management 
process requires the timely availability of reliable and accurate information about 
the state of the planet's ecosystems and the effect that human activities have on 
them. Beginning with this premise, this paper introduces the concept of an 
Information Delivery System centered on remote sensing of the earth from space, 
and examines some of the critical technological concepts that are fundamental to 
the successful creation of such a system, and therefore to the ultimate attainment 
of a process of sustainable development. 
INTRODUCTION 
The recent explosion in knowledge about our home planet has taught us that the global 
environment which sustains us is in a somewhat fragile equilibrium. We have come to realize that if 
we do not pay attention to the effect of human activity on the state of the environment, we could 
perturb it in ways which are irreversible and ultimately toxic to the survival of our species and many 
others which currently inhabit the earth. The prospect of global warming and the apparent 
depletion of the ozone layer as consequences of human activity are but two of the more well- 
known early manifestations of our ability to upset nature's equilibrium. It is generally accepted that 
human activity began to have significant effects on the environment at the time of the industrial 
revolution. If one examines the period since then, while there is evidence of some effect on 
environmental equilibrium due to human activity primarily in the industrial countries, there is no 
doubt that the quality of life for the average person in those countries has increased markedly 
during this period . These improvements have their roots in the very increase in economic activity 
which lies at the root of the negative effects we are having on the environment. While it appears 
that our long-term survival as a species will depend on our ability to act in ways which preserve the 
ecosystem of planet earth in its current state of natural equilibrium, none of us, whether we live in 
the industrialized countries or the so-called developing world is anxious to accept significant 
curtailment of continuous improvement in our quality of life through what is commonly referred to 
as "economic development". The challenge then becomes one of achieving economic growth 
while at the same time sustaining the ability of our planet to continue to support our own and 
other species for the indefinite future. This is an exciting challenge for all of us. In the words of the 
World Commission on Environment and Development: 
"Humanity has the ability to make development sustainable -- to ensure that it 
meets the needs of the present without compromising the ability of future 
generations to meet their own needs. The concept of sustainable development 
* Keynote paper presented at the ISPRS Mid-term Symposium on Global and Environmental Monitoring: 
Techniques and Impacts, Victoria, B.C. Canada, September 18,1990.