Bush accused of distorting evidence on climate change

The Bush administration has been accused of routinely misleading the public over the threat of global warming and of orchestrating efforts to try to suppress scientific findings that highlight the reality of climate change.

The chairman of a Congressional committee investigating the administration's actions said yesterday that government officials had sought repeatedly "to mislead the public by injecting doubt into the science of global warming". Democrat Henry Waxman also said the government was refusing to make public documents that would expose its behaviour.

Meanwhile, two pressure groups provided survey findings to the committee that suggested almost half of federal climate scientists who responded said they had experienced pressure to eliminate the words "climate change" or "global warming" from their writings. One third said they had experienced officials at their agencies making public statements that misrepresented their findings.

There have long been accusations that Mr Bush's government has interfered with scientific findings for ideological and political reasons. In the field of reproductive health, it has discredited the effectiveness of condoms for preventing sexually transmitted diseases and refused to authorise emergency contraception. In oncology it has sought to show a link between breast cancer and abortions.

But nowhere has the government's efforts been more focused than in the field of global warming - something Mr Bush has only recently been willing to publicly accept has a link to human activity. Despite the belated acknowledgement, he remains adamantly opposed to an enforced reduction of greenhouse gas emissions.

Mr Waxman said his committee had sought documents from the White House that would reveal its strategy but the government had not been forthcoming. He added: "We know the White House possesses documents that contain evidence of an attempt by senior administration officials to mislead the public by injecting doubt into the science of global warming and minimise the potential danger."

The committee heard testimony from several scientists, including Dr Drew Shindell, a researcher at Nasa's Goddard Institute for Space Studies. Mr Shindell said that, in 2004, a title for a paper he had prepared about climate change in Antarctica was "softened" by political appointees at the White House. "I objected, but was anonymously overruled, and the lack of transparency in the process made it very difficult to appeal," he said.

According to the findings of a survey by the Union of Concerned Scientists (UCS), Mr Shindell's experience is not unique. Questionnaires sent to scientists at seven federal agencies found that more than 40 per cent had experienced changes to their work which altered the meaning of their findings.

The continuing focus of climate change comes as some 500 scientists gather in Paris this week to complete a United Nations report on how global warming is likely to affect sea levels.

Meanwhile, in Washington, Mr Bush has signed a directive that will give him greater control over government policy statements on public health, the environment and civil rights.