The industry is concerned that plans to make oil and gas platforms and other offshore infrastructure part of the third phase of the European Emissions

Trading Scheme (ETS), which begins in 2013, would effectively impose an unfair tax on the industry as it is not possible to power platforms and equipment using anything other than fossil fuels. Oil and gas producers would be forced to buy extra carbon permits to make up for their pollution under the scheme, and will also suffer steadily rising costs as newer offshore equipment uses more power than older equipment.

The industry claims the ­potential lost investment could lead to 900 million barrels of the remaining 25 billion barrels of North Sea oil equivalent being left under the water – which has attracted accusations of “scaremongering” from the environmental lobby.

Malcolm Webb, chief executive of industry association Oil and Gas UK, said: “Ideally, we want an exemption, although we would settle for compensation. If we go on neglecting the need to maximise our indigenous oil and gas resources, all that we will do is to increase our energy insecurity as a nation.”

Webb contrasted electricity ­generation, which is done with offshore turbines powered by hydrocarbons that have just been extracted, with other platform activities such as gas flaring, which the industry does not object to being covered by the ETS.

“We have raised concerns with the government, but we have so far got nowhere. The government doesn’t see the magnitude of the problem as we see it. It sees a lower number than the 900 million, but whatever that number, this is still a real concern,” he said.

Duncan McLaren, chief executive of Friends of the Earth Scotland, said it was “morally outrageous” for the oil lobby to be predicting reduced investment and damaged energy security.

“I have heard this argument from all parts of the energy industry that the lights will go out unless we give them tax breaks or other assistance. It’s just scaremongering.

“Even if we take the argument at face value that investment in the North Sea would fall, a rise in energy imports would not be necessary if we reduced our demand through energy efficiency. There are European and UK targets to cut it by 20% by 2020, which is pretty substantial. If they are saying they are going to cut production by more than that because of incentives to disinvest, it doesn’t add up.”

Webb’s comments came on the back of widespread concern over Copenhagen and future carbon emissions targets at the biennial Offshore Europe conference in Aberdeen last week. The oil industry’s argument is that it would be dangerous to over-burden producers with environmental targets in the short to medium term, since they will still be needed to deliver the majority of world energy for at least the next couple of decades.

Christophe de Margerie, chief executive of Total, told the conference that governments needed to “be careful” with carbon.

“We all are concerned about the environment, but we need to know what will be the price,” he said. “When we have to develop new tougher fields it will mean more emissions, but there is a time when you have to think what you want.”

He had also expressed concerns that Copenhagen would see the Europeans imposing the toughest targets on themselves while other countries got off more lightly.

Connie Hedegaard, the Danish climate change minister and Copenhagen organiser, used the Aberdeen conference to call on the industry to raise its game to help develop a decent energy infrastructure in the shortest possible time.

She said companies had a choice between “rejecting and delaying” or “recognising and dealing” with the problem, and she feared that the voices calling for action to be postponed might hold sway unless politicians redoubled their determination.

“It’s do-able provided we all have the political will, and you [the oil and gas industry] can help us create that will and pressure,” she said.