• A personal note on IGBP and the social sciences

    Humans are an integral component of the Earth system as conceptualised by IGBP. João Morais recalls key milestones in IGBP’s engagement with the social sciences and offers some words of advice for Future Earth.
  • IGBP and Earth observation:
    a co-evolution

    The iconic images of Earth beamed back by the earliest spacecraft helped to galvanise interest in our planet’s environment. The subsequent evolution and development of satellites for Earth observation has been intricately linked with that of IGBP and other global-change research programmes, write Jack Kaye and Cat Downy .

People on the land: Changes in global population and croplands during the 20th century

Ambio (2002)
Ramankutty N, Foley J A and Olejniczak N J (eds)
ISSN: 00447447
Doi: 10.1579/0044-7447-31.3.251
Vol 31; Issue 3; pp. 251-257

This study reviews the major changes in global distribution of croplands during the 20th century. During the 20th century, the cropland base diminished greatly (from ~ 0.75 ha person1 in 1900 to ~ 0.35 ha person1 in 1990). This loss of croplands was not globally uniform: more than half the worlds population, living in developing nations, lost nearly two-thirds of their per capita cropland base. The distribution of croplands has become increasingly skewed in 1990, 80% of the population lived off less than 0.35 ha person1. While agricultural yields have generally increased, they have barely kept pace with population growth in developing nations. Overall, the global food production system is becoming increasingly vulnerable to regional disruptions because of our increasing reliance on expensive technological options to increase agricultural production, or on global food trade.

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