The land area of the Earth covers a total of more than 140 million km2
- somewhat less than one-third of the Earth's surface. Land resources are
finite, fragile and non-renewable. They include soil, which is mainly important
for agriculture; land cover, which is important for the environment; and
landscapes which are an important component of human habitat and welfare.
Besides forming a basis for plant and animal life support systems and agricultural
production, land aids in the preservation of terrestrial biodiversity, regulation
of the hydrological cycle, carbon storage and recycling, and other ecosystem
services. It acts as a store of raw materials, a waste dump and landfill
for both solid and liquid waste, and a basis for human settlement and transport
activities (FAO 1995a, Wood, Sebastian and Scherr 2000).
The 1992 Earth Summit took a step forward in bringing problems associated
with land resources to wider attention. In Agenda 21 (UNCED 1992),
Chapters 10, 12, 13 and 14 relate to land, covering the integrated approach
to management of land resources, desertification and drought, mountain
region development and sustainable agriculture. In the discussions of
deforestation, biological diversity and freshwater resources (Chapters
11, 15 and 18), significant emphasis is placed on land as a productive
resource, the importance of sustainable land use, and environmental pollution
and conservation. Agenda 21 has remained a primary basis for land
resources policy although a further landmark of awareness of land at the
highest policy level is found in the review prepared for the UN Millennium
Summit (UN 2000). This review identifies the threats to future global
food security arising from problems of land resources.