The former head of one the United States’ leading scientific agencies has said she fears for the “very future of our democracy” if scientists are “muzzled and intimidated” by Donald Trump’s administration.

Speaking to a packed house of about 250 people at the American Association for the Advancement of Science’s (AAAS) annual meeting, former National Oceanic and Atmospheric Administration (NOAA) chief Professor Jane Lubchenco said she was even concerned for the “health and well-being of scientists” amid warning signs that she described as “very sobering”.

Since Mr Trump was elected he has appointed a string of climate change deniers to key positions in government, information about climate change has been deleted from federal websites and staff at the Environmental Protection Agency were told not to speak out publicly without approval.

This ‘gag order’ was described by Professor Barbara Schaal, president of the AAAS, as “chilling” when she opened the meeting.

An event organised by the Union of Concerned Scientists (UCS) at the annual meeting saw emotions run high as some people in the crowd compared Mr Trump to the Italian fascist leader Benito Mussolini and his administration to the Nazis in 1930s Germany.

However, one of the founders of the UCS, Kurt Gottfried, who was a child in Austria when the country was annexed by Germany in 1938, said such comparisons were “ridiculous” at the moment – but also warned they might not be in the future.

Ms Lubchenco, who was the NOAA administrator from 2009 to 2013, told the audience: “My biggest worry is about the consequences to society if scientists are muzzled and intimidated, if science is defunded, data deleted and scientific institutions are undermined.

“I fear for the health and well-being of scientists and the economy and the environment, indeed the very future of our democracy and our world.

“Why? We need science at the table for individuals and for institutions to make smart decisions. We need data to help citizens and businesses be smart about what they do, we need science to create the new knowledge that will help society solve many of the big problems that are facing us.”

She said it was unclear whether her worst fears would become reality but added “we have warning signs that are very sobering”.

“I fear that neither policymakers nor citizens will have access to the best available science because federal scientists are afraid or unable to do their best science and to share it with the public and policymakers,” Ms Lubchenco said.

“I fear that the scientific integrity policies that are essential for wise decision-making… will be either ignored or dismantled. I fear that science will seen increasingly as partisan and untrustworthy.”

The controversial orders Donald Trump has already issued Show all 9 1 /9 The controversial orders Donald Trump has already issued The controversial orders Donald Trump has already issued Trump and the media White House Press Secretary Sean Spicer takes questions during the daily press briefing Getty Images The controversial orders Donald Trump has already issued Trump and the Trans-Pacific Partnership Union leaders applaud US President Donald Trump for signing an executive order withdrawing the US from the Trans-Pacific Partnership negotiations during a meeting in the Roosevelt Room of the White House in Washington DC. Mr Trump issued a presidential memorandum in January announcing that the US would withdraw from the trade deal Getty The controversial orders Donald Trump has already issued Trump and the Mexico wall A US Border Patrol vehicle sits waiting for illegal immigrants at a fence opening near the US-Mexico border near McAllen, Texas. The number of incoming immigrants has surged ahead of the upcoming Presidential inauguration of Donald Trump, who has pledged to build a wall along the US-Mexico border. A signature campaign promise, Mr Trump outlined his intention to build a border wall on the US-Mexico border days after taking office Getty Images The controversial orders Donald Trump has already issued Trump and abortion US President Donald Trump signs an executive order as Chief of Staff Reince Priebus looks on in the Oval Office of the White House. Mr Trump reinstated a ban on American financial aide being granted to non-governmental organizations that provide abortion counseling, provide abortion referrals, or advocate for abortion access outside of the United States Getty Images The controversial orders Donald Trump has already issued Trump and the Dakota Access pipeline Opponents of the Keystone XL and Dakota Access pipelines hold a rally as they protest US President Donald Trump's executive orders advancing their construction, at Columbus Circle in New York. US President Donald Trump signed executive orders reviving the construction of two controversial oil pipelines, but said the projects would be subject to renegotiation Getty Images The controversial orders Donald Trump has already issued Trump and 'Obamacare' Nancy Pelosi who is the minority leader of the House of Representatives speaks beside House Democrats at an event to protect the Affordable Care Act in Los Angeles, California. US President Donald Trump's effort to make good on his campaign promise to repeal and replace the healthcare law failed when Republicans failed to get enough votes. Mr Trump has promised to revisit the matter Getty Images The controversial orders Donald Trump has already issued Donald Trump and 'sanctuary cities' US President Donald Trump signed an executive order in January threatening to pull funding for so-called "sanctuary cities" if they do not comply with federal immigration law AP The controversial orders Donald Trump has already issued Trump and the travel ban US President Donald Trump has attempted twice to restrict travel into the United States from several predominantly Muslim countries. The first attempt, in February, was met with swift opposition from protesters who flocked to airports around the country. That travel ban was later blocked by the Ninth Circuit Court of Appeals. The second ban was blocked by a federal judge a day before it was scheduled to be implemented in mid-March SANDY HUFFAKER/AFP/Getty Images The controversial orders Donald Trump has already issued Trump and climate change US President Donald Trump sought to dismantle several of his predecessor's actions on climate change in March. His order instructed the Environmental Protection Agency to reevaluate the Clean Power Plan, which would cap power plant emissions Shannon Stapleton/Reuters

Scientists could decide to quit Government jobs or not apply for them, affecting everything from the quality of weather forecasts to new sources of renewable energy and the safety of medicines, she said.

But Ms Lubchenco also appealed to people not to make science a partisan issue.

“It isn’t, it shouldn’t be and don’t buy into that framing of the debate,” she said.

The eminent physicist, Professor Lewis Branscomb, who has advised four US Presidents, echoed that point as he suggested some politicians in Mr Trump’s own party might prove to be allies.

“A great many of the leading Republicans are very nervous about where all this is going to lead,” he said.

“If there is a chance of having strong friends anywhere in the conservative community, then don’t put them in the pot with everything else we plan to cook.”

He appeared taken aback by the heady atmosphere of the meeting.

“The energy is right here in the room, look at it, we’ve never had a meeting like this,” Mr Branscomb said.

But some among the audience expressed fears that the dangers posed by Mr Trump were being underestimated.

In pictures: Women of the world march against Trump Show all 32 1 /32 In pictures: Women of the world march against Trump In pictures: Women of the world march against Trump London An image of President Donald Trump is seen on a placard during the Women's March in London, England Getty In pictures: Women of the world march against Trump Sydney A view of the skywriting word reading 'Trump' as thousands rally in support of equal rights in Sydney, New South Wales EPA In pictures: Women of the world march against Trump Rome People shout and hold signs during a rally against US newly sworn-in President Donald Trump in Rome Getty Images In pictures: Women of the world march against Trump London A protester holds a placard during the Women's March in London, England Getty Images In pictures: Women of the world march against Trump Marseille A placard ready 'Pussy grabs back' is attached to the handle bar of a bike during a 'Women's March' organized by Feminist and human rights groups in solidarity with women marching in Washington and around the world for their rights and against the reactionary politics of the newly sworn-in US President Donald Trump, at the Old Port (Vieux Port) of Marseille, southern France Getty Images In pictures: Women of the world march against Trump Bangkok A young Thai girl holds a "women's rights are human rights" sign at Roadhouse BBQ restaurant where many of the Bangkok Womens March participants gathered in Bangkok, Thailand Getty Images In pictures: Women of the world march against Trump Bangkok A Thai woman takes a photo of a "hate is not great" sign at the women's solidarity gathering in Bangkok, Thailand Getty Images In pictures: Women of the world march against Trump Bangkok American expats and travellers gather with the international community in Bangkok at the Roadhouse BBQ restaurant to stand in solidarity in Bangkok, Thailand Getty Images In pictures: Women of the world march against Trump London Protetesters gather outside The US Embassy in Grosvenor Square ahead of the Women's March in London, England Getty Images In pictures: Women of the world march against Trump Marseille Women's March at the Old Port (Vieux Port) of Marseille, southern France Getty Images In pictures: Women of the world march against Trump Marseille Protestors hold placards reading 'My body my choice, my vote my voice' during a 'Women's March' organized by Feminist and human rights groups in solidarity with women marching in Washington and around the world for their rights and against the reactionary politics of the newly sworn-in US President Donald Trump, at the Old Port (Vieux Port) of Marseille, southern France Getty Images In pictures: Women of the world march against Trump Rome A person holds a sign during a rally against US newly sworn-in President Donald Trump in Rome Getty Images In pictures: Women of the world march against Trump Kolkata Activist Sarah Annay Williamson holds a placard and shouts slogan during the Women's March rally in Kolkata, India AP In pictures: Women of the world march against Trump Kolkata Activists participate in the Women's March rally in Kolkata, India AP In pictures: Women of the world march against Trump London A Women's March placards are rested on a bench outside the US Embassy in Grosvenor Square ahead of the Women's March in London, England Getty Images In pictures: Women of the world march against Trump London A women carries her placard ahead of the Women's March in London, England Getty Images In pictures: Women of the world march against Trump Manila Women protesters shout slogans while displaying placards during a rally in solidarity against the inauguration of President Donald Trump, in suburban Quezon city, northeast of Manila, Philippines AP In pictures: Women of the world march against Trump Berlin Protesters attend a 'Berlin Women's March on Washington' demonstration in front of the Brandenburg Gate in Berlin, Germany AP In pictures: Women of the world march against Trump Berlin Protesters attend a 'Berlin Women's March on Washington' demonstration in front of the Brandenburg Gate in Berlin, Germany AP In pictures: Women of the world march against Trump Berlin Protesters attend a 'Berlin Women's March on Washington' demonstration in front of the Brandenburg Gate in Berlin, Germany AP In pictures: Women of the world march against Trump Melbourne Protesters take part in the Melbourne rally to protest against the Trump Inauguration in Melbourne, Australia Getty Images In pictures: Women of the world march against Trump Macau Protesters take part in the Women's March rally in Macau Getty Images In pictures: Women of the world march against Trump Melbourne Womens march on Melbourne protestors marching during a rally where rights groups marched in solidarity with Americans to speak out against misogyny, bigotry and hatred Rex In pictures: Women of the world march against Trump Macau Protesters hold placards as they take part at the Women's March rally in Macau Getty Images In pictures: Women of the world march against Trump Macau Protesters hold placards as they take part at the Women's March rally in Macau, Macau. The Women's March originated in Washington DC but soon spread to be a global march calling on all concerned citizens to stand up for equality, diversity and inclusion and for women's rights to be recognised around the world as human rights Getty Images In pictures: Women of the world march against Trump Manila A mother carries her son as they join a rally in solidarity against the inauguration of President-elect Donald Trump as the 45th President of the United States in suburban Quezon city northeast of Manila, Philippines AP In pictures: Women of the world march against Trump Sydney An infant is held up at a demonstration against new U.S. President Donald Trump in Sydney, Australia Getty Images In pictures: Women of the world march against Trump Sydney A woman attends a demonstration against new U.S. President Donald Trump in Sydney, Australia Getty Images In pictures: Women of the world march against Trump Sydney A woman expresses her Anti-Trump views in Sydney, Australia Getty Images In pictures: Women of the world march against Trump Sydeney Protesters demonstrate against new U.S. President Donald Trump in Sydney, Australia. The marches in Australia were organised to show solidarity with those marching on Washington DC and around the world in defense of women's rights and human rights Getty In pictures: Women of the world march against Trump London Protesters march from The US Embassy in Grosvenor Square towards Trafalgar Square during the Women's March in London, England Getty In pictures: Women of the world march against Trump London Protesters carrying banners take part in the Women's March on London, as they stand in Trafalgar Square, in central London Reuters

Jeremy Grantham, the Boston-based investment strategist known for steering investors away from coming crashes and who set up the Grantham Foundation For the Protection of the Environment, accused scientists of having a lack of passion.

“I think scientists actually think passion is not scientific. They have enormous respect for the dignity of science,” he said.

“They understate their work on climate change and that is simply dangerous if it leads to a lack of understanding by senior politicians.

“This is a matter of real survivability for certainly our society as we know it and for many species – including our own.”

Mr Grantham said there was a need for scientists to speak out more strongly on such issues and “it shouldn’t take the second coming of Mussolini” to provoke such a response.

And Dr Phil Rice, of Harvard Medical School and an emergency doctor, went further.

“This is an authoritarian fascist government. All these institutions that people are hoping to rely upon to keep him and his group in check I think are just going to fold,” he said.

“This is a locomotive coming at us… just like they did in Germany, they will come for the scientists, this is just the first salvo.

“They will attack the scientists and they will imprison them. I think part of the response has to be that we are going to protect each and every one of us that gets attacked.

“Even if you just do your science and don’t speak out, you will get attacked. The universities are going to be gone after just as they are beginning to.”

However Mr Gottfried advised against comparing Mr Trump to the far-right leaders of 1930s Europe.

“I saw my school yard filled with tanks and my sky filled with German fighter planes,” he said.

“I’ve experienced what you are talking about and I want to warn you about over-stating the case.

“I think the US is not Germany or Austria in 1938. We have a lot of strengths we can rely on.

“We damage ourselves by exaggerating the threat. This country has strengths that Germany did not have, to equate the two is ridiculous.

“Unfortunately you may turn out to be right, but to talk now as if it is a forgone conclusion is a mistake.

“You may help the people who want [a] Hitler to come to power. I’ve seen what you are talking about and it’s not what we are facing. It may be, but we help it come about if we make exaggerations that are really way off.”