I notice you’re concerned with CO2 being released into the atmosphere. But CO2 is truly a minor part of the Earth temperature dynamics, and by far the major “greenhouse gas” is water vapor, which concetration tends to counteract CO2 changes. At least this is the theme presented in a simple essay “The Saturated Greenhouse Effect” (with references to original hard research) on friendsofscience (org or com?) in which the mainstream model shows warming of air at 6-13 km elevation over a broad equatorial zone – but it was recently shown NOT TO EXIST! So the basic model is wrong. And what is the correct model?

Well, average Earth surface temperature is (except for radioactive decay inside the Earth) a matter of how much light and energy is REFLECTED back out. Reflection is enhanced by clouds that tend to be nucleated by cosmic particles, that are blown away by solar flares! the solar flare connection is developed nicely by a Prof at my alma mater (MIT) in a terrific video on youtube “The Great Global Warming Swindle” – have a look! (Oh, it is damned by some “greenie” folks!) It even traces the history of funding for “evil CO2″ studies back to a British PM who hated coal mine unions. She aimed to close British coal
entirely.

Looking at Earth atmosphere going back to Precambrian times, I have evolved a view on energy that points to a dramatic way to deal with our largest energy need (and to solve or help in three other “problem” areas.) I write a book, of course… (ha ha.)

Good luck in coal, we still need the stuff for many uses, and it is a very amazing window on past life.

Typically less than 20% of what the US Energy Information Admininistration (EIA in the Department of Energy) calls “reserves” are economically recoverable.

The United States Geological Survery (“USGS”) has done a series of reports examining economic recoverability. Several of these are summarized in Chapter D of the National Coal Resource Assessment issued in June 2009 available at http://pubs.usgs.gov/pp/1625f/ .

You’ll find a summary of economic recoverability of coal on page 12 of Chapter D of the NCRA. Chapter D is available at http://pubs.usgs.gov/pp/1625f/downloads/ChapterD.pdf .

A full report as well as other resources examining the economic availability of US coal supplies and the remaining life of existing mines is available from http://www.cleanenergyaction.org.

The direct link for the fully referenced report on US coal supplies is http://cleanenergyaction.org/coal-supplies.