The document discusses the importance of sustainable living. It notes that our lives and economies depend on resources from the earth, and that living sustainably means living off the earth's natural income without depleting resources. It then discusses some key issues with the current unsustainable model like CO2 emissions, deforestation, and population growth. Deforestation is removing forests faster than they can regrow, which causes problems like droughts, wildfires and animal extinction. High CO2 emissions from fossil fuel use are also causing problems like more severe weather. The document argues that societies need to pursue more sustainable economic development that improves lives without degrading earth's life support systems. It provides some examples of sustainable practices around resource and energy use.