'No threat'

Nasa said in a statement: "Several minutes into the flight of the Taurus rocket ... launch managers declared a contingency after the payload fairing failed to separate."

The $278m mission was designed to place the satellite into orbit about 650km high to help improve climate models and help researchers determine where the greenhouse gas originates and how much is being absorbed by forests and oceans.

The launch rocket was carrying hydrazine fuel but Nasa officials said there was no sign that the satellite posed any threat.

A team of Nasa experts is being assembled to investigate the incident.

Dangerous warming

Last month Japan successfully launched the world's first satellite to monitor global warming emissions.

Scientists currently depend on 282 land-based stations and information from aircraft flights to monitor carbon dioxide at low altitudes.

Carbon dioxide is believed to be the main greenhouse gas which traps heat from the sun, causing potentially dangerous warming of the planet.

Carbon dioxide emissions rose three per cent worldwide from 2006 to 2007, according to international science agencies.