Political leaders in most functioning democracies have established checks and laws to ensure that their countries are guided by knowledge. On 14 June, President Donald Trump took one of his biggest steps yet to dismantle an important part of this system in the United States: an executive order that federal agencies should cut the number of advisory panels by at least one-third.

This is not just another of his ill-informed policies, or one that only wonks care about. It is the government making itself stupid. Ignoring, suppressing or manipulating science advice has been a pattern of this administration; now the very committees that provide that advice are being eliminated.

Scientists must sound the alarm.

As the research director of the Center for Science and Democracy at the Union of Concerned Scientists in Washington DC, I’ve long studied the use and misuse of science in government decision-making. The federal advisory system — which includes both science and stakeholder committees — is a safeguard. It ensures that policy decisions are guided by evidence, even when there is political pressure to ignore information.

There are roughly 1,000 such committees, totalling some 60,000 members. To address issues from drug laws to foodborne illness, government agencies rely on the advice of leading specialists. Committees at the Department of Transportation make public transit safer; panels at the Department of Agriculture oversee food safety, and so on.

The Trump administration’s assault on science will have an impact far beyond this presidency. The loss of institutional knowledge, technical training and overall capacity in the government won’t simply be restored through the election of a science-friendly administration. It will take years to rebuild. Meanwhile, federal science agencies will struggle to fulfil their missions of protecting public health and safety, and the environment.

The committees now under threat also help the public to hold decision-makers accountable when they ignore important evidence. In 2008, the administration of George W. Bush — and in 2011, that of Barack Obama — failed to set a standard for ambient levels of ozone (an air pollutant that causes respiratory and cardiovascular distress) that the seven-member Clean Air Scientific Advisory Committee recommended. The recommendation enabled the public to challenge the administrations’ decisions. Without an advisory committee, the lines between science assessments and policy decisions are blurred.

The executive order is ostensibly a cost-cutting measure. But federal advisory committees are a bargain for taxpayers. Agency staff run a few meetings a year, alongside other duties, and some compensation is granted for economy-class travel and other expenses that committee members incur. According to the US Federal Advisory Committee Act Database, the Clean Air Scientific Advisory Committee spent US$951,860 in 2018, of which only $110,540 went to direct committee costs. (The rest went to existing staff members, who would have been paid anyway.) Thousands of world-class specialists donate their time to help the government to make informed decisions.

Also, every meeting of an advisory committee solicits public comments. This gives community advocates and people without easy access to government officials a way to make their views known. The upcoming cull will give the public less opportunity for input.

External advice has been one of the main targets of the Trump administration’s many attempts to sideline science. In 2017, the head of the Environmental Protection Agency (EPA) issued a directive to remove advisers with current EPA grants (individuals whose expertise the EPA clearly found useful). The agency retained advisers tied to industries that have financial interests in EPA regulations.

Our analysis found that, in the first year of the Trump administration, federal science advisory committees met less frequently than in any of the 21 years since the government started tracking them. Nearly two-thirds of these committees met less often than their charters direct. We have also logged more than 100 attacks on the use and communication of science in the Trump administration so far, more than for any other president. These include avoiding or removing terms such as ‘climate change’, halting a study by the US National Academy of Sciences and reversing a decision to ban a pesticide linked to neurological conditions in children.

Those actions have chipped away at the nation’s access to science advice. The executive order takes a jackhammer to it. By asking agencies to arbitrarily eliminate one-third of their advisory committees, the president is essentially asking which wheel you’d like removed from your car. Which is it to be: water quality, air pollution or chemical waste?

James Madison, the fourth president and a founding father of the United States, wrote, “Knowledge will forever govern ignorance; And a people who mean to be their own Governors, must arm themselves with the power which knowledge gives.” We owe it to ourselves and our expertise, to the United States and the many other nations affected by its decisions — on emissions, infectious agents, drugs and so much more — to insist on being governed by knowledge, not ignorance. Speaking up for science panels is speaking up for democracy.

So what to do? Push back, demand action. Use the power of constituency, urge Congress for oversight, and even go to court if necessary. This is not about partisan politics; it is about making decisions based on the best available information.