The failure of world leaders in Copenhagen to reach meaningful agreement on carbon emissions is not merely disappointing to climate activists: business leaders say the political failure to set reduction targets leaves them without enough certainty to justify the massive investments needed to begin to move toward low-emissions economies.

The political order is widely felt to have substantially let down business leaders. Yesterday, Yvo de Boer, chief UN climate change official, said he expects to see "growing demands on the part of business to see this accord turned into something that is legally binding".

Peter Voser, chief executive of Dutch Shell, said more was needed. "It remains unclear how this political willingness will translate intoconcrete steps." Wulf Bernotat, chief executive of the European energy group Eon, warned cuts would "depend on further progress" in the UN talks. Bankers say Copenhagen's failure is likely to undermine confidence in the market for carbon credits.

US business leaders, too, say tougher clean energy standards and a price floor for oil and gas supplies would help raise green-tech investment and force companies to invest in less-polluting equipment. By some estimates, the private sector will need to provide 90 per cent of the $500bn-a-year investment needed to keep global warming at or below two degrees.

But with individual countries now supposed to fill in details of planned cuts in greenhouse gas emissions that the Copenhagen accords failed to establish, disappointment at the outcome has led some business leaders to conclude that business cannot wait for politicians to act.

Sir Richard Branson told Bloomberg he believes industry will have to go it alone. "We owe it to the public to get our house in order," he said. "If the governments won't set targets then I would suggest that the airlines get together and do it themselves and set an example."

Last week, businesses including Microsoft, Duke Energy, Nike, and Dow Chemical wrote to President Obama urging him to push for a treaty with "substantial" financing goals. "Such an agreement will provide the market certainty that will unleash the investments needed to create jobs," the letter concluded.

With the failure of Copenhagen apparent, there is a growing feeling that expecting politicians to act beyond short-term political self-interest is itself poor thinking. Lester Brown, president of the Washington-based Earth Policy Institute, says our politicians are simply not up to the task. "They are obsolete. They take too long to negotiate and ratify. In this case, the game may be over by then."

But while Obama and other political leaders brace themselves for the fall-out for coming home empty-handed, some businesses say the elevation of the global warming issue in Copenhagen to a global imperative is still of some benefit.

"It's helpful," says Russell Mills, global director energy and climate-change policy at Dow Europe. "The key issue is we have started on a global process."