The March for Science is a response to the Trump administration’s distaste for science — or at least the kind that gets in the way of profit — but it is also a celebration of those among us who have devoted their lives to understanding how the world works. The thousands descending on the National Mall, on the first Earth Day under a regime that has taken a sharp knife to government science budgets, study stars and butterflies, barrier reefs and hedgehog reproduction, viruses and bird flight patterns. Most days, they make and test their hypotheses in laboratories or perhaps in the Arctic Circle or the Australian Outback, in an anti-gravity chamber or a deciduous forest. But on this rainy April Saturday, they have come together in Washington, D.C, to make a point that feels more urgent than ever: Science matters, and we ignore its findings at our peril. Michael Mann (shown above), a climatologist and geophysicist, has pioneered computational models based on patterns of the past 600 years of climate changes. Mann is perhaps best known for the “Hockey Stick graph,” which shows a sharp uptick in global temperatures starting around 1900. And he was one of the lead authors of the 2001 Intergovernmental Panel on Climate Change report, which helped establish the scientific consensus about the global phenomenon. But Mann may be proudest of his most recent work documenting the sometimes subtle impacts the climate is having on hurricane activity, extreme weather events, and phenomena like El Niño. “This is an area of the science where there is still legitimate debate and a lot of interesting work left to be done,” he said, “much of it steeped in basic physics where I got my start.” Mann is marching because “Science and scientists are now under attack in this country.” He should know. Mann is one of the favorite targets of climate deniers, as evidenced most recently by a hearing of the House Committee on Science, Space and Technology at which he was the only witness representing the mainstream view that climate change is the result of human activity. “When congressional Republicans are denying basic science,” Mann said, “and the Trump administration — run largely by polluting interests — is trying to revoke policies to protect our health and our environment, more than ever we need to hear the voices of scientists, loudly and clearly.”

Mary Droser at Lincoln Park in Washington, D.C., on Friday April 21, 2017. Photo: Matt Roth for The Intercept

“Not all species are equal,” said Mary Droser, a paleontologist who uses fossils to study how ecosystems develop and change over time. “You take out a particular species, a keystone species, and the whole thing crashes. That’s why so many people are now worried about the Great Barrier Reef.” Having studied the rise and fall of past species can make our current crisis particularly scary. “When people say save the earth, I think the earth will be fine. It’s humanity that I’m worried about. We know from the past that, in terms of extinctions, and in terms of environmental change, the tipping points come sooner than we think.” Droser finds it absurd that the current administration “wants to pick and choose what science to believe.” Still, she considers herself an optimist. “You can’t just go into despair,” she said. “What am I going to do, tell my 16-year-old that I’m just going to sit this one out?”

David Guggenheim in Washington, D.C., on Friday, April 21, 2017. Photo: Matt Roth for The Intercept

“We’re starting to realize how seriously our oceans are in trouble,” said David Guggenheim, a marine biologist who studies coral reefs. Since 1970, the Caribbean has lost about 50 percent of its reefs. For the past 17 years, Guggenheim has been working in Cuba, which has some of the healthiest coral reefs left in the Caribbean. The Cuban reefs have thrived because the country has protected its coastal waters — and also hasn’t suffered the effects of large-scale tourism or agriculture. Also, said Guggenheim, “they actually listen to their scientists. There’s no climate debate there like we have here.” Protecting fish is essential for protecting reefs, said Guggenheim. “We think of fish as something to eat, as crops that grow in the ocean. But they have jobs to do and one of them is keeping coral reefs healthy.” Guggenheim is marching because he’s alarmed by the anti-science bent of the new administration. “I’m used to getting around the table with the opposition. I’m used to compromising. But this is different,” said Guggenheim. “It’s a throw-back to the dark ages. The problem is the voice of science is not being heard. The voice of Trump is being heard.”

Melanie Killen at her home in Bethesda, Md., on Friday, April 21, 2017. Photo: Matt Roth for The Intercept

Melanie Killen is a developmental scientist who looks at the emergence of moral concepts from early childhood to adulthood. Theorists used to speculate that morality emerged in adolescence. But Killen and her team showed that a sense of right and wrong begins to form in children who are as young as 3, 4, and 5. By age 5, Killen’s team showed, children can also understand and account for relative advantage. Asked to divide supplies between two schools that have unequal resources, for instance, children will often choose to give a larger share to that the one with less. “They start saying things like, ‘well you have to give them more because then it’ll all be fair,” she said. Killen is marching to stand up for continued support for basic science. “The U.S. has been a leader in the world in terms of basic research funding for everything from child health to space exploration and cures for cancer,” she said. “The idea that we are reducing that funding is a terrible blow to progress.”

Jessica Ware at the National Mall in Washington, D.C., on Friday April 21, 2017. Photo: Matt Roth for The Intercept

Jessica Ware is an evolutionary entomologist. Her work focuses on dragonflies, which were the first creatures to fly on earth and are also among the fastest of the animals responding to climate change. Ware has traced the evolution of the insects’ genes through fossils, which date as far back as 250 million years ago, and follows current dragonfly populations in the Yukon and the northern-most points of the world. “Trying to understand how, when and why they evolved helps us understand where the planet is now and where it’ll be in the future,” said Ware. She is marching, in part, to highlight the importance of evolution. “The U.S. is lagging behind almost every single country in terms of the general public’s belief in evolution. But it’s not something to be believed. It’s a process that creates life and causes things to go extinct. It exists.” Ware also wants all young people to know that they could be scientists, something she didn’t realize as a child. “I am an African American woman with LGBT family,” said Ware. “When people think of science, they don’t think of someone who looks like me.”

John Vadermeer and Ivette Perfecto, ecologists at the University of Michigan, at Lafayette Square in Washington, D.C., on Friday, April 21, 2017. Photo: Matt Roth for The Intercept

“Most science gets done for the benefit of the powerful,” said John Vandermeer. “We feel it should be done for the benefit of everyone.” Vandermeer and his wife, Ivette Perfecto, have worked together for 37 years, using ecological principles to improve agriculture. For much of that time, they have focused on coffee production in Puerto Rico. They have also established a coffee plantation in Chiapas, Mexico, where they research interactions among pests and their natural enemies. Agriculture is a major cause of both climate change and species extinctions. But Vandermeer and Perfecto have been studying more sustainable ways of growing, focusing on natural systems that control pests without pesticides. They’ve recently developed games that help farmers understand the complexity of ecosystems. For Perfecto, the march is about more than science. “I feel like we’re losing democracy,” she said. “Science is just one of the casualties.”

Robin Wall Kimmerer, outside her hotel in Rockville, Md., on Friday April 21, 2017. Photo: Matt Roth for The Intercept