L. David Roper
http://www.roperld.com/personal/roperldavid.htm
6 April, 2016
In my quest to analyze data of global systems that are affected by or affect global warming, I have been looking for data about the deforestation of rain forests to analyze. The only good set of data I have found so far are for the Brazilian rain forest:
I take as "data" from the second column the values for 1977 and 1988-2008, and values of 4 for 1970 and 4.1 for 1900. A datum for 2009 is given in Nature 25 Nov 2010, vol. 468, p.489.
Units: 1 km^2 = 100 hectares = 0.3861 mi^2; 1 hectare = 10,000 m^2 = 2.471 acres = 107,639 ft^2.
I used the hyperbolic tangent function to fit the data. The best fit is:
The fit is 
, where a = 4.10, b = 3.21, t0 = 1993.1 and w = 20.7 .
One could be pessimistic and assume that humans will cut down the Brazilian rain forest until it is all gone, as has happened at other places on the Earth:
The "disappear" fit has seven times the chi square as the fit that levels off at ~3.2x106 fit.
It appears that the destruction of the Brazilean rain forest is coming to a close after about a 20% loss. Can that 20% be regained?
http://en.wikipedia.org/wiki/Rain_forests
http://en.wikipedia.org/wiki/Amazon_Rainforest
http://en.wikipedia.org/wiki/Deforestation
http://en.wikipedia.org/wiki/Deforestation_in_Brazil
http://rainforests.mongabay.com/amazon/
L. David Roper interdisciplinary studies
L. David Roper, http://www.roperld.com/personal/roperldavid.htm