Here's some "basic", "high-level" info...;
At the most simple level, the land "owner", only owns the surface. The Crown owns whatever is underneath! I think most people are aware of that concept.
Coal Seam Methane / Coal Seam Gas - this "product" is actually a big problem for Underground Coal Mines... Canary in coal mine concept... This is the exact gas that kills the canary before the humans... This is what killed those people at Pike River (?), NZ, a few years back.
In these Coal Seam Gas "Zones", there are actually several layers, or seams of Coal, which could actually be mined in the future... Although hopefully we can use Solar & Wind, before they get to the point of mining these zones...
Yes, the environment is impacted on, both at the surface, and underground at the well sites, and surrounds...
The Fiscal Effect: there is "MEGA" money pouring into our Australian Economy as a result... To the point where even Lego profits from this... Excess money, results in purchasing of expensive Lego kits!

Gas - as a resource:... We all love gas these days... Heating our homes in Winter... The harsh reality is that we all like to stay warm, we have bigger houses now, and the population is growing, and we are using more and more gas...
Gas in Europe - traditionally, The Russians supplied the bulk of Europe's Gas... But now Italy, Germany and others are sick of that Black Market, and BP (and others) are gearing up to build new pipelines into Europe, via the South East Route, through Turkey, and not via Russia. Although the bulk of the gas will come from the exact same region... Caspian Sea Region. Azerbaijan is on the western edge, and they will 'profit' from this... Even many Aussies will be involved... Quite a few Aussie guys are already there, or are about to go there... They have built up experience from building the pipelines through Queensland...
Germany - they claim to be almost 100% running on Wind & Solar, but this it total Bull Crap! They still have about 20 Nuclear Reactors running, although they are switch maybe 1 off per year... But I bet they are only switching off the smaller older ones... Not sure, I haven't researched it in detail. In Germany, wind is effectively better than Solar, and The Wind works at night (usually!), for when you want to use lights, and electric heating, in Winter, etc... But Germany also uses masses of Gas for heating... Cold Climate... EVERYONE WANTS GAS!
There's no easy answers either way... This is just a bit of "mostly factual" stuff that is going on...