The article "Human Appropriation of the Products of Photosynthesis" by Peter M. Vitousek, Paul R. Ehrlich, Anne H. Ehrlich, and Pamela A. Matson examines the significant impact of human activities on the Earth's biosphere. The authors calculate the fraction of net primary production (NPP) that humans have appropriated, which is the energy left after subtracting the respiration of primary producers from the total energy fixed biologically. They use three methods to estimate human influence: a low estimate based on direct human consumption, an intermediate estimate that includes all human-dominated ecosystems, and a high estimate that accounts for potential NPP lost due to land conversion and desertification. The low estimate is 7.2 Pg of organic material directly used by humans annually, representing about 3% of the biosphere's total annual NPP. The intermediate estimate is 42.6 Pg, or 19% of total NPP, which includes co-opted NPP from human-dominated ecosystems and potential NPP lost due to land conversion. The high estimate is 58.1 Pg, or 38.8% of potential terrestrial productivity, which accounts for both co-opted NPP and potential NPP lost due to human activities such as deforestation and desertification. The authors conclude that human activities have significantly altered the Earth's biosphere, leading to species extinctions and genetic diversity loss. They argue that current patterns of exploitation and consumption could support a much larger human population without depleting a significant portion of the Earth's resources. The article highlights the need for sustainable practices to manage the Earth's resources effectively.The article "Human Appropriation of the Products of Photosynthesis" by Peter M. Vitousek, Paul R. Ehrlich, Anne H. Ehrlich, and Pamela A. Matson examines the significant impact of human activities on the Earth's biosphere. The authors calculate the fraction of net primary production (NPP) that humans have appropriated, which is the energy left after subtracting the respiration of primary producers from the total energy fixed biologically. They use three methods to estimate human influence: a low estimate based on direct human consumption, an intermediate estimate that includes all human-dominated ecosystems, and a high estimate that accounts for potential NPP lost due to land conversion and desertification. The low estimate is 7.2 Pg of organic material directly used by humans annually, representing about 3% of the biosphere's total annual NPP. The intermediate estimate is 42.6 Pg, or 19% of total NPP, which includes co-opted NPP from human-dominated ecosystems and potential NPP lost due to land conversion. The high estimate is 58.1 Pg, or 38.8% of potential terrestrial productivity, which accounts for both co-opted NPP and potential NPP lost due to human activities such as deforestation and desertification. The authors conclude that human activities have significantly altered the Earth's biosphere, leading to species extinctions and genetic diversity loss. They argue that current patterns of exploitation and consumption could support a much larger human population without depleting a significant portion of the Earth's resources. The article highlights the need for sustainable practices to manage the Earth's resources effectively.