BIOL 350 Lecture Notes - Lecture 3: Carbon Sink, Scientific American, Water Cycle
12 Nov 2016
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Document Summary
*see figure* from the mid 1950s to present there has been an increase in the amount of arable and cropland particularly in asia, north america and africa. So more arable land per capita has gone down about 25% expected by 2025. Minerals a lot of minerals now have a finite lifespan for extraction. In the last 30 years extraction has doubled. *scientific american how much is left predicts there is about 15 more years of silver left (2029), gold about 15 years (2030), copper (about 2044 gone). Many metal elements go into the production of electronic devices even if we are recycling. Most of the places where minerals are happen to also be underneath important crop land, farm land and forests. So when we extract it the wastes from extracting destroy this viable land = secondary impact. Forests not just a source of fuel, fiber and lumber.
