As a one-time Pennsylvanian, this issue is of great interest to me, firstly, because Pennsylvania is at the center of the fracking controversy, and secondly, because I am very familiar with the Centralia Coal Fires.

The coal fires, if you don't know, are coal seam fires that have been burning in the the tunnels under Centralia since a garbage fire accidentally ignited them 1962, much to the chagrin of everyone who once lived and worked there. No one has been able to put them out.

I didn't realize it for many years, but the Centralia fires are far from isolated. There are hundreds of these fires spewing toxic and inflammable gases from mines all around the world. And they are not a new phenomenon. Apparently, a coal seam fire in Germany burned for more than 400 years.

Now, given that many of the posters in this thread are from the UK, and have a charming tendency to say,"Well, that is the sort of thing you'd expect in America", I tried to find info on Coal Seam Fires in
the British Isles. I didn't find anything, but I found out that there are currently efforts to introduce Underground Coal Gassification, which, in quick brushstrokes, is a method of generating mineable gas by setting coal seam fires.

Now, far be it from me to encourage Lizzie Cornish in anyway, but...