Section One
PLENARY AND BANQUET ADDRESSES
1    GLOBAL CHANGE AND THE RIO EARTH SUMMIT:
PROSPECTS FOR THE FUTURE
Jerald L. Schnoor, UI Foundation Distinguished Professor
Department of Civil and Environmental Engineering
Center for Global and Regional Environmental Research
The University of Iowa, Iowa City, Iowa 52242
INTRODUCTION
Humans have always been in tension with their environment as they seek out a better standard of
living; land has been cleared for agriculture or commerce, and animal populations have been
exploited. What is different about the situation that we find ourselves in today is the magnitude of our
impacts. We are more numerous. 5.5 Billion people on earth seek out an existence, and they are
multiplying. Every six months, there is another contingent of people equal in population to the
country of France, about 50 million. Imagine, every six months another France for whom to provide
food, housing, shelter, and jobs. Every ten years, there is another population the size of China. And
coupled with population is the problem of an ever-increasing per capita consumption among developed countries, especially. We are powerful. Twin juggernauts: burgeoning population and per capita
consumption are driving the global change problems discussed at the Rio Earth Summit in Rio de
Janeiro, Brazil, on June 3-15, 1992.
The Earth Summit was officially entitled, "The United Nations Conference on Environment and
Development." To discuss environment in the same breath as development is something new. They are
no longer considered oxymorons. Rather, they are inextricable concepts that go hand in hand. We
cannot have sustainable economic development without a healthy environment and resource base, and
we cannot have a good environment without a productive economy that provides for attention to
environmental problems. To do otherwise results in the legacy of problems that we see in Central and
Eastern Europe today. As an environmental engineer, I naively went to the Rio Earth Summit
thinking that it was a meeting solely about the environment, and I came away realizing that the
environment is merely the backdrop for global issues of social justice, poverty, and politics. As long as
there are 1.3 billion people on earth without adequate drinking water supplies, 2.3 billion without
access to sanitary facilities, and millions of children dying of water-borne diseases, we cannot ignore
issues of resource allocation and global governance.1
The Earth Summit was also about issues of global change: greenhouse gases, stratospheric ozone
depletion, and declining biodiversity. These are the so-called "loud problems" brought to the table at
Rio with such urgency by the developed countries.1 Most of these problems were created by the
developed countries themselves. Frequently, the developed countries patented and profited from the
technologies that created these problems. Under such circumstances, it is difficult to garner much
sympathy or ardent support for action from the developing world. Nonetheless, the problems are real
and demand attention.
Greehouse gases are increasing rapidly in the atmosphere. Carbon dioxide from fossil fuel emissions is increasing at 0.5% per year. A little more than half of the anthropogenic greenhouse gas effect
is due to carbon dioxide (Table I).2 Methane concentrations in the atmosphere, another potent
greenhouse gas, are increasing at -0.9% per year, mainly due to flooded agriculture (rice production)
and animal husbandry to feed an expanding population. Chlorofluorocarbons (CFCs) are increasing
several percent per year, depending on which one is discussed. Although the Montreal Protocol and
updates have banned CFC production by the year 2000, the gas concentration in the atmosphere is
likely to increase for another decade. Half-lives for the CFC chemicals in the atmosphere are on the
order of decades to 200 years, so the problem will be with us for a long time. Nitrous oxide concentrations (N20) are primarily the result of fossil fuel emissions, biomass burning, and increasing nitrogen
48th Purdue Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.