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  • Early climate on Mars
    Based on mineral and environmental data gathered by the Mars Science Laboratory Rover Curiosity, a study estimates that Martian carbon dioxide levels approximately 3.5 billion years ago were orders of magnitude lower than the level of carbon dioxide needed to warm early Mars as indicated by climate models, suggesting that mechanisms as yet unknown reconciled the presence of a lake environment with an atmosphere incapable of warming the site to temperatures above freezing.
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  • Pre-Columbian builders and Amazonian forests
    A study of Amazonian rainforests in western Brazil, which contains more than 450 monumental pre-Columbian earthworks called geoglyphs, finds that the current bamboo forest has dominated the landscape for more than 6,000 years, and that pre-Columbian societies disturbed small areas in managed, palm-rich forests to construct the geoglyphs, providing insights into the exploitation of forest products for millennia prior to modern deforestation.
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