The Bush administration has routinely suppressed or ­distorted communication of climate change science to the public, a climate specialist at Nasa’s Goddard Institute said on Tuesday.

The accusation, before the chief oversight committee in the House of Representatives, was reinforced by claims by Democratic lawmakers that the White House was withholding documents proving that Philip Cooney, a former Bush administration official who now works as a lobbyist for ExxonMobil, regularly edited climate reports for political reasons.