Seeing the environmental forest

One of the most useful features about models, both statistical and physical, is that you can examine different aspects of the system you are analyzing separate from all other other influences.  Want to see if El Niño/Southern Oscillation could be driving the trend in global temperatures?  Construct a realistic model, then isolate the ENSO term.  Want to see if a combination of natural cycles explains the trend?  Isolate the terms for the natural cycles from those for greenhouse gases, and examine the results.

After digging through the recent State Department Environmental Impact Statement for the Keystone XL Pipeline , I am quite disappointed.  While right-wingers are cheering the fact that the State Department found that building Keystone XL won't have an impact on greenhouse gas emissions, that is the wrong conclusion.  In reality, the State Department found that the tar sand oil flowing through Keystone XL will generate the equivalent of 147 to 168 million metric tons of CO 2 emission per year (Executive Summary, page 15).  That is a sizable contribution to greenhouse gas emission from one single project.  It's between 57% and 65% of the average total CO2 emissions from all the world's volcanoes combined (average combined volcanic emissions per year: 260 million metric tons, see Gerlach 2011 ) and enough to raise atmospheric CO2 levels by 0.021 ppmv per year.  And the State Department somehow thinks that isn't going to impact greenhouse gas emissions? So, how c...