The Millennium Ecosystem Assessment is an extensive study of global changes in ecosystems and their potential impact on human beings. It was launched in 2000 by the former United Nations Secretary-General Kofi Annan and started in 2001. More than 1.360 researchers contributed to the assessment of key ecosystem services. The results were published in 2005. Apart from the main report, "Ecosystems & Human Well-being: Synthesis Report", several more specific reports, e.g. "Biodiversity", "Desertification", "Health" or "Wetlands & Water-Synthesis" have been published. One of the main results of the study is that changes in the Earth's ecosystems due to human activities were more rapid and more pronounced in the past 50 years than at any time in human history. The growing need for food, freshwater, wood, fibres and fuels continues even today to cause a substantial and irreversible loss of biological diversity.