Four organisations – the World Bank, the UN Development Programme, the UN Environmental Programme and the World Resources Institute – recently collaborated on the most ambitious study of global ecosystems ever undertaken. The first results of this project, called a Pilot Analysis of Global Ecosystems, were presented to a special sitting of the United Nations in 2001.

The goal of the investigation was to answer the most important question of the century: What is happening to Earth’s capacity to support nature and humankind. The report divided its conclusions into assessments of five major types of ecosystems – forest, freshwater systems, coastal/marine habitats, grasslands and agricultural lands – and all the studies indicated that all five systems are showing signs of deterioration. Half of the world’s wetlands have been lost in the past century; 58 percent of coral reefs are imperilled by human activity; 80 percent of grasslands are suffering soil degradation; 20 percent of dry-lands are in danger of becoming deserts; and groundwater is being depleted almost everywhere.

Architects create habitats, and instead of creating artificial or alien habitats that are fashionable, they can assist in rehabilitating and enlarging local and national biodiversity through their projects.

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12.7.1 Fresh Water and Ground Water

Water is essential to life: the human body is about 75 percent water, with up to 85 percent of brain cells liquid. Around 71 percent of the planet is covered in water, but 97,5 percent of it is salt water, and of the remaining 2,5 percent, some 70 percent is frozen in the polar caps and around 30 percent is present as soil moisture or in underground aquifers. Less than 1 percent is thus accessible for direct use by humans, animals and plants.

Consequently, an estimated 1 billion people around the globe lack clean drinking water and about 3 billion do not have adequate sanitation. Humankind is currently using about 40 percent of the available freshwater. It is anticipated that by the year 2050 this will have risen to 90 percent, leaving only 10 percent for animals and plants.

Yet 40 percent of the water used globally is for sanitation and other uses in buildings. The operation of buildings places a strain on raw water reserves, while wastewater and sewage needs to be treated before being returned to watercourses.

12.8.6 Pollution

The leeching of chemicals into the soil is one of the most severe environmental impacts a development can have on a site. Asbestos – now banned in many countries – can remain in the soil for hundreds of years, practically freezing the use of such soils for many generations. In the past environmental legislation – and awareness – of these impacts was non-existent, leading to widespread environmental devastation. Pollutant run-off to rivers kills fish and poisons the water, impacting on the watershed structure for many kilometres downstream. Fortunately, awareness leading to a better legislative environment is in place now and the interrelationships between things are better understood.

However, even small-scale chemical leeching, such as the disposal of turpentine used to clean paintbrushes, must be avoided