Peak oil: the summit that dominates the horizon  

The Guardian seems to be running a lot of peak oil articles lately - one recent example declares "Crude is still being discovered; existing fields are not being exploited to the full. So it's hard to predict the exact point at which the world's dwindling reserves will precipitate a crisis. But it's coming" - Peak oil: the summit that dominates the horizon.

Massive new oil finds off the southern states of America and Brazil plus exciting discoveries in currently non-producing countries such as Ghana and Uganda sit uneasily with claims the world is running out of crude.

BP recently boasted about a "giant" strike on the Tiber field in the Gulf of Mexico and BG, the former exploration arm of British Gas, talked of its "supergiant" at the Guará prospect off South America, yet critics argue they cannot make up for the fast depletion of existing fields.

These "peak oil" believers say the high point of oil output could even have passed already. They argue it will take 10 years to develop the likes of Tiber while a string of similar discoveries would have to be made at very regular intervals to move the peak point back towards 2030 the projection used in some scenarios put forward by the International Energy Agency.

The debate has intensified in recent weeks after whistleblowers claimed the IEA figures were unreliable and subject to political manipulation – something the agency categorically denies. But the subject of oil reserves touches not just energy and climate change policy but the wider economic scene, because hydrocarbons still oil the wheels of international trade.

Even the Paris-based IEA admits that the world still needs to find the equivalent of four new Saudi Arabias to feed increasing demand at a time when the depletion rate in old fields of the North Sea and other major producing areas is running at 7% year on year.

"The fields which are producing today are going to significantly decline. We are very worried about these trends," says Fatih Birol, the chief economist at the IEA, who has gradually ramped that depletion figure upwards and has expressed deep concerns at a huge fall-off in the current levels of investment in the sector.

Birol and the wider industry are certainly well aware that the days of "easy" oil are over. The big international companies such as BP and ExxonMobil are struggling to find enough new oil to replace their exploited reserves year-on-year and Shell found itself on the end of a major fine for exaggerating its reserves report to the Securities & Exchange Commission in the US.