• References:
    • NASA Fact Sheets - Earth Science Enterprist Series (accessed 4/14/99) Biosphere. http://www.gsfc.nasa.gov/gsfc/service/gallery/fact_sheets/earthsci/eos/biosphere.pdf
    • EPA (1999) Global Warming: Climate Change and Wisconsin. http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/SHSU5BWK6D/$File/wi_impct.pdf