Editing Carrying capacity (section)

=== Millennium ecosystem assessment ===
The Millennium Ecosystem Assessment (MEA) of 2005 was a massive, collaborative effort to assess the state of Earth's ecosystems, involving more than 1,300 experts worldwide.<ref name=":0" /> Their first two of four main findings were the following. The first finding is:<blockquote>Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber, and fuel. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth.<ref name=":1">Reid, W. V., et al. (2005). ''The millennium ecosystem assessment: Ecosystems and human well-being.'' Washington, DC: Ecosystems and Human Well-Being: A Synthesis, p. 1.</ref></blockquote>The second of the four main findings is:<blockquote>The changes that have been made to ecosystems have contributed to substantial net gains in human well-being and economic development, but these gains have been achieved at growing costs in the form of the degradation of many ecosystem services, increased risks of nonlinear changes, and the exacerbation of poverty for some groups of people. These problems, unless addressed, will substantially diminish the benefits that future generations obtain from ecosystems.<ref name=":1" /></blockquote>According to the MEA, these unprecedented environmental changes threaten to reduce the Earth's long-term human carrying capacity. “The degradation of ecosystem services could grow significantly worse during the first half of this [21st] century,” they write, serving as a barrier to improving the lives of poor people around the world.<ref name=":1" />