Organizers of a March for Science in Washington, D.C., say they expect huge crowds in the nation’s capital and at more than 425 affiliated marches across the globe on Saturday, April 22, including Tucson.

The Tucson group, meanwhile, has shelved its plan to march from De Anza Park to El Presidio Park downtown after learning it would need about $20,000 to barricade North Stone Avenue, hire off-duty police and medics, and take out insurance.

The meat of the event, a Rally for Science at El Presidio Park, will be held from 10 a.m. to 2 p.m. with bands, speakers and booths promoting science outreach, staffed by nonprofits and student groups from the University of Arizona.

It’s not quite the same as marching, said Marea Jenness, a Tucson High Magnet School science teacher, who is planning logistics for the event. She also helped with the Tucson “sister” march of the Women’s March in January.

“I want to walk,” she said. “It’s the activity that people engage in to show they’re protesting. It’s hard to be active at a rally.”

Jenness said she will participate in an informal “Women March for Science” group that is gathering at 9 a.m. at Armory Park to walk along the sidewalks to El Presidio.

Other groups are planning similar mini-marches, she said.

Jenness said organizers decided to pull the plug on the main march after realizing it would be difficult to raise the money to fund all the infrastructure the city required for a permit to march down Stone Avenue. Barricades alone would require about $9,000.

Jenness said she encountered similar costs for the Women’s March in January, but that group was able to raise the funds easily on social media.

The Rally for Science also has some competition. April 22 is Earth Day and the UA has scheduled a celebration at Biosphere 2 — an event that will include many of its most prominent climate scientists. Earth Day events are also being held that day at the Tucson Children’s Museum and a “People’s Climate March” is scheduled at El Presidio Park the following Saturday.

Heatherlee Leary, one of the organizers of the Tucson rally, said the group is still hoping for a turnout of 2,500 to 5,000 supporters of science.

“It’s a rally and a science-outreach event,” she said. “It’s not only a protest, it is also an opportunity to support the local science community.”

Leary, a natural resources student at the UA, said the group is also hosting a prerally speaker series.

Details are on the group’s website: marchforsciencetucson.org

Josh Hoskinson, a UA graduate student in Ecology and Evolutionary Biology, said he’s heard mixed response from faculty at the university, some of whom don’t want to be viewed as partisan.

“The problem is that it is a reaction to the change, and even more so, the mentality of the administration. The proposed budget still reflects the mentality of where the administration’s priorities are, and they are not with science,” Hoskinson said.

Rachel Gallery, an assistant professor of natural resources at UA, will speak at the rally as a representative of the group "500 Women Scientists." She said she understands the reluctance of some scientists to participate in what could be regarded as political acts.

“Scientists, in general, are cautious people, cautious by nature, due to the nature of our jobs and the process we use — the scientific method,” she said.

Gallery said she is not marching or rallying against anything. “I am marching in support of science,” she said.

“It’s very important for us to show how much science has helped and served society in every single way. I also think that one of science’s most important roles, besides providing a fundamental understanding of how the world works, is to inform policy — present data that can be used to make decisions that affect our lives.”

UA environmental scientist Scott Saleska plans to march on behalf of science on Earth Day, April 22, in Washington.

Saleska has personal and professional reasons for concern. The Trump administration has identified his field of study as the target of federal cuts.

The president has called climate change a hoax and his administrator of the EPA, Scott Pruitt, has said there is “tremendous disagreement” among scientists on the causes of global warming.

“This statement is incorrect,” said a letter sent to Pruitt by Saleska and 29 other prominent scientists, including UA colleagues Jonathan Overpeck and Joellen Russell.

“In fact, we know with an exceptionally high degree of confidence that most of the climate warming over at least the last six decades has been caused by rising levels of carbon dioxide and other greenhouse gases in the atmosphere due to the burning of fossil fuels and other human activities,” the letter said.

Saleska said the same group of scientists made the same argument in an amicus brief to the U.S. Supreme Court 10 years ago, when several states successfully sued the EPA to force it to regulate carbon dioxide emissions.

Saleska, who studies the carbon cycle in rainforests, said scientific thought on global warming isn’t partisan.

“Science doesn’t care about global warming. Science doesn’t care whether the Earth is destroyed. People care, and then they do something, and we have a Clean Air Act that gives a mandate to EPA to address that risk,” he said.

Astronomer Laird Close also plans to join his fellow scientists in D.C. on April 22, even though his field of study is not under attack. He is concerned the administration wants to still the voices of scientists.

Close, a Canadian citizen who has worked at the University of Arizona since 1991, said something similar happened during the administration of former Canadian Prime Minister Stephen Harper, whose Conservative government ordered scientists not to talk to the press.

Close said early moves by the Trump administration seemed to threaten similar silencing of scientists here.

“I saw a parallel with what was going on with the new administration and what went on in Canada. We don’t want to see a muzzling of our scientists to push an ideological agenda of any party,” he said.

Protesting doesn’t come naturally to scientists, Close said.

“I actually don’t do politics,” said Close. “I don’t view science as Republican or Democratic and I think all scientists feel pretty strongly that way.”

It’s very important that it doesn’t get viewed as a bunch of scientists who are against the current administration,” he said.

Close said he hopes large numbers of people turn out to support science.

“Obviously, a single person going to Washington and holding up a sign doesn’t change anything,” he said.

“It’s an important exercise in civics, so I’m excited in bringing my two daughters who are 10 and 12 to sort of see democracy in action. The march for science is something I feel strongly about and I want to pass that enthusiasm on to my daughters.”

All of the scientists interviewed for this story made it clear they were speaking for themselves and not for their employers.

Contact: tbeal@tucson.com or 573-4158. Follow him on Facebook or on Twitter: @bealagram