The info on these pages was taken from my OAC biology textbook (Biology: Discovering Life by Levine/Miller copyright 1991) and some class notes, as an attempt to study for my exam.
Humans have transformed Earth's beautiful landscapes by clearing forests and grasslands for our crops. Over the last 2000 years, as technological and medical advancements have allowed us to live longer and support more offspring, world population has soared from around 130 million to way over 5 billion. For just under 2 million years, small populations of humans exploited their surroundings to provide life's necessities. Some cultures such as New World native people either lived in harmony with nature or learned to exploit natural environments in a sustainable fashion. Others however, such as Easter Islanders miscalculated their impact on their immediate surroundings and were destroyed by ecological collapse. In the last several decades, problems such as toxic waste dumps and pockets of polluted air have besieged cities ranging from Niagara Falls to L.A., yet most environmental issues were seen as local concerns caused by local problems and affecting local people. More recently however, the growth of human populations and the impact of our expanding technology have had effects well beyond the local level. Human activity is affecting the air we breathe, the water we drink, the soil we depend on and the climate.
The following describe in more detail some of the human impacts on the biosphere to date.
© 1999 Kristina
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