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close this bookDiversity, Globalization, and the Ways of Nature (IDRC, 1995, 234 p.)
View the document(introduction...)
View the documentAcknowledgments
View the documentForeword
close this folder1. Introduction
View the documentGlobalization and the ways of nature
View the documentThe new globalization processes
close this folder2. Global trends and their effects on the environment
View the documentThe information revolution
View the documentDevelopment of global financial markets
View the documentDevelopment of more effective transportation networks
View the documentMovement of people
View the documentGlobalization and the unequal distribution of wealth
View the documentInternational migration
View the documentThe development of free markets
close this folder3. Planet-wide deterioration
View the document(introduction...)
View the documentOur sister planet
View the documentThe unusual, oxygenated planet
View the documentThe paradox of ozone
View the documentOceans can be degraded too
View the documentThe rivers are becoming muddy
View the documentOvershooting
close this folder4. Forests under attack
View the document(introduction...)
View the documentDeforestation in the 20th century
View the documentRain-forest environments
View the documentTemperate forests
close this folder5. Grasslands
View the documentSavannas
View the documentThe temperate grasslands
View the documentModifying grassland ecosystems
View the documentEnvironmental balance in grassland ecosystems
close this folder6. Aquatic ecosystems
View the documentExtractive exploitation
View the documentThe future of fish production
close this folder7. Managing planetary thirst
View the documentSome basic facts
View the documentWater supply and options
View the documentThe demand side of the issue
View the documentWater issues throughout the world
close this folder8. Protecting air quality
View the document(introduction...)
View the documentAir and its principal contaminants
View the documentProcesses of contamination in industrial and urban areas
View the documentCurrent and future trends
close this folder9. Clean energy for planetary survival
View the document(introduction...)
View the documentThe industrial revolution
View the documentThe use of hydroelectricity
View the documentThe age of petroleum
View the documentNuclear power
View the documentThe clean options
close this folder10. Africa in the 21st Century: Sunrise or sunset?
View the document(introduction...)
View the documentThe causes of poverty
View the documentHistorical causes of the current situation
View the documentWars are environmentally unfriendly
View the documentEvolution of environmental management in Africa
View the documentOld and new development models
close this folder11. Latin America and the Caribbean: A history of environmental degradation
View the document(introduction...)
View the documentIndigenous cultures
View the documentThe colonial period
View the documentExploitation of natural resources after independence
View the documentEffects of globalization on the environment
View the documentThe maquiladora phenomenon
close this folder12. The urban environmental challenge
View the documentThe development of modern cities
View the documentLarge cities in the Third World
View the documentThe megacities of today
close this folder13. Diversity and human survival
View the document(introduction...)
View the documentDocumenting diversity
View the documentResources for the future
View the documentDiversity of living systems
View the documentCauses and effects of the loss of natural diversity
View the documentDiversity and culture
View the documentRestoring what is lost
View the documentBiodiversity and research
close this folder14. Strategies for the future
View the document(introduction...)
View the documentDecentralize decision-making
View the documentPeople value their environment
View the documentProblems and responsibilities are global
View the documentBibliography

The rivers are becoming muddy

Some time ago, Erhart (1968), traveling by ship along the Congo and Amazon rivers, was puzzled by the lack of turbidity in the water - no sediments, no clays, nothing of the brown colour that one expects of mighty rivers draining such large basins. Eventually, he realized that the clear water was natural. These large streams flowed from rain-forest basins, where there was no erosion. Chemical processes of organic origin predominated. Although the water in these rivers was carrying salts, resulting from the leaching of ions from the soils they drained, no sediments were being transported. Ions of calcium, sodium, potassium, magnesium, and silicon and carbonates, phosphates, and chlorides were carried in the water in small proportions, producing a gradual increase in the salinity of the sea and supplying raw materials for the shells of sea organisms.

Erhart also realized that the old processes of soil formation (weathering) in rain-forest environments were the origin of limestone. Today’s calcareous mud at the bottom of the ocean is the current equivalent of the ancient limestones formed (by biostasy) 100 or 200 million years ago during the Mesozoic era, when dinosaurs roamed the Earth. However, the calcareous muds of the past were buried by younger sediments, composed of claystones, siltstones, and associated sandstones (what geologists call “flysch”), during a drier period that followed the humid period that produced the limestones. Erhart concluded that the forest had disappeared and that subsequently the soils had been eroded; he called this situation, in which mechanical processes predominated, rhexistasy.

Today, large forests are disappearing even faster as a result of human action. Deforestation is widespread. Forests are logged or burned, leading to soil erosion; rivers are becoming filled with muddy sediments. Flying over the Amazon brings new surprises every year: its tributaries are becoming yellow or brown in colour; the Amazon itself is no longer dark green; and in geological terms, the forest is starting to die.

In ancient times, forests would die, but others were born. There were always sufficient trees to maintain a low level of CO2. Now, as all forests are being cut back at the same time, we suspect there is considerable risk to the planet’s dynamics.