I think these increses are result of improved technology.
When a well is drilled, the fact that oil or gas is found does not mean that the well will be completed as a producing well. The determining factor is economics. If the well can produce enough oil or gas to cover the additional cost of completion and the ongoing production costs it will be put into production. But now we need to develop new things, such as biofuels from waste plant material and wind and wave power. If you believe that hydrocarbons are the cause of climate change, we need to find ways of capturing carbon dioxide and storing it because there is no question that we will have to burn coal and natural gas for many more years. Apart from government, which means the taxes, there is no prospect of paying for this without oil profits - a power station equipped with carbon capture and storage would cost lesser than what we have now right?