"If I were a business man I would say “please please please do a deal in Copenhagen, and please please please make it market based"," said De Boer, speaking on the second day of the Copenhagen climate change summit . "Because if we fail to get a market based deal here and if the US Senate fails to pass cap and trade legislation then the EPA will be obliged to regulate. And every businessman knows that taxes and regulations tend to be a lot more expensive and lot less efficient than market based approaches," said De Boer.

De Boer said that the talks had "got off to a good start", but predicted tough negotiations when ministers and then heads of government arrive next week.

"I have heard representatives of both Europe and the US say that the target that China has tabled can be improved upon; I have heard representatives from Europe and China say that the target tabled by the US can be improved upon ... and I have heard the Island states and the least developed states say that nobody's targets are good enough at the moment," de Boer said. "So clearly we are going to have a very intense process of negotiation to get us to the maximum possible."

De Boer added: "We all know that the targets that are on the table at the moment from rich countries are not good enough to get us into that minus 25-40% range that scientists refer to as a place we need to be." "And I think that those world leaders are coming here for a very serious negotiation on how they can maximise ambition both in industrialised countries and in major developing nations and how they can put the money on the table which will allow the developing nations to really engage substantially."