The upcoming Oil production peak AND the upcoming Natural Gas shortage are inter-related but two different problems.
First peak oil is when world wide oil production peaks and than starts to drop. We will be pumping oil for another 100 years BUT whenever peak oil hits, demand will exceed supply and that will be a permanent situation. On the other hand OIL will still be around, its price will go up but we will still have some oil (through less and less each year till it is all used in about 100 years).
The upcoming Natural Gas shortage is different, unlike oil Natural Gas is a gas and as a Gas each well produces its maximum volume until it is empty (Oil is a liquid and a liquid's production starts up slow than increase till it peaks and than drops, Oil follows a bell curve it its production life).
Thus the problem with Natural gas is once each well is out it is out, you can not come back to it for years after peak production and get some more out of it. With Natural Gas you produce than you cap.
Just like Oil, Natural gas worldwide follows more or less the same pattern as most of its wells, but while Oil is a Bell shape production curve, Natural Gas is a cliff. That is what we are running into right now for Natural Gas, more and More wells are NO longer producing and are thus closing down. We have less well coming on line (and the tend to be smaller fields so they are consumed quicker than the older wells).
Peak oil is a bad enough a problem, the upcoming Natural Gas cliff is worse.
One side affect, the biggest remaining pools of Natural Gas are in the former Soviet Union (FSU) and Iran, both of which are connected by pipeline to Europe. The US has been using Canadian Natural Gas to supplement its own but if it wants nay more Natural gas it has to import form the same area (Nigeria has some also but shipping from Africa to the US has the same problems as Iran and FSU to the US).
One of the problem of natural gas is that the best way to transport it is by pipeline. Unlike Oil (which is a liquid) shipping by ship is much more costly for natural Gas than through a pipeline. The main reason for this is to ship by Ship, you MUST liquidity the Gas, which takes the energy of about 1/3 of the Natural gas being Liquidized (The process is by Compression). An additional cost is that the compressed gas has to be kept in heavy duty containers to keep it from escaping. These containers increase the weight of the shipping vessel and with that increased weight the cost to move the ship.
One of the advantages Europe has over the US is it can get its Natural Gas by pipeline NOT ship. Thus Europe's costs for USING Natural Gas is going to be lower than the future use of Natural Gas in the US. This was one of the problem with the Kyoto Treaty, Europe knew it could use Natural Gas while the US best alternative to Peak oil is Coal.
For more information see:
http://www.peakoil.net/This site is run by Geologists who have concern about peak oil, as opposed to the survivilist types worried about a Government take over.