Hundreds of scientists gathered in Boston’s Copley Square over the weekend to express their concerns about, and to protest against the policies of President Donald Trump’s administration.

The rally, which included crowds holding bright signs such as “Stand up for science,” “Science is not a liberal conspiracy,” “Science, not silence” and “Climate change is NOT a controversy,” had sponsors that included the Union of Concerned Scientists, Greenpeace USA, Mass Sierra Club and groups from universities in the area, according to Scientific American.

Although not directly sponsored by or affiliated with the annual meeting of the American Association for the Advancement of Science (AAAS) — a five-day conference that opened nearby on Wednesday with the theme "Serving Society Through Science Policy" — the protest rally was offered support by the CEO of AAAS, who backed plans to hold similar rallies under the banner "March for Science," scheduled to be held on Earth Day, April 22, in Washington and across multiple cities.

"It is partly because of the previous statements of the president and his appointees on issues such as climate change and vaccination for children which have not been in keeping with good science," Rush Holt, AAAS CEO, explained to BBC News.

"But mostly by what we have seen since the new administration has come in, [which] is silence about science. Very few appointments to positions are filled by people who understand science, very few comments about the importance of science; there is no science advisor in the White House now and we don't know whether there will be one…and so the silence is beginning to sound ominous," he said.

The AAAS conference included lectures that reflected contemporary political issues such as the psychology of “fake news,” and how to protect climate science from hostile governments. It also saw the participation of several scientists who walked over from the conference to take part in the rally. Several of the event organizers gave speeches and addressed the rallies over the weekend.

“I’m concerned that we’re going to lose the EPA. I’m concerned that we’re going to lose regulations that have a direct impact on human health, like automobile emissions…People will get sicker. People will die because of a lack of environmental regulation and medical research,” Jacquelyn Gill, an ecologist at the University of Maine and one of the speakers addressing Sunday’s rally, told the Guardian.

Beka Economopoulos, one of the event organizers and the director of the mobile and pop-up Natural History Museum, explained that one of the big concerns are the arguments regarding “trimming the fat” of budgets because science and medical research funding already make a minuscule proportion of the federal budget.

“That money has got one of the best returns on investment you could possibly hope for…the real stakeholders are the citizens that stand to gain or lose the most if the institutions are weakened,” she said. Beka also expressed apprehension at the appointment of Oklahoma attorney general Scott Pruitt’s as head of the EPA.

“We have a sort of fox in the henhouse situation here with Scott Pruitt as head of the EPA, an agency that he has sued 14 times,” she told the Guardian.

“This is about freedom of inquiry…from the muzzling of scientists and government agencies, to the immigration ban, the deletion of scientific data, and the defunding of public science, the erosion of our institutions of science is a dangerous direction for our country. Real people and communities bear the brunt of these actions,” Economopulos told the crowd, according to the BBC.

However, not every scientist was optimistic about the rally. Eminent string theorist Jim Gates, for instance, said that without an end goal in mind, the movement may be perceived as “science against Trump”.

“At least as far as I can detect, there is no theory of action behind this…This bothers me tremendously…I don’t understand how the organizers of this march can guard against provocateurs, quite frankly…I don’t think they’re ready for that, I don’t think they’re considering that kind of danger. To have science represented as this political force I think is just extraordinarily dangerous,” he warned.