The March for Science, which takes place on Saturday in more than 500 cities across the world, is an implicit rejection of President Donald Trump and his embrace of “alternative facts” over objective truth. But it’s also a defense of science itself, which thrives on federal funds and faces massive cuts under Trump.

Organizers and proponents of the march generally admit that their actions on April 22, which is Earth Day, won’t change Trump’s mind about science or about these cuts. But they hope the event will be educational enough that more citizens will step up and defend the importance of research. “There needs to be a public dawning ... that how science is practiced actually makes a difference in their lives,” Dr. Rush Holt, the CEO of the American Association for the Advancement of Science and executive publisher of the Science journals, told me earlier this year. He called the march “a rare opportunity for scientists to help get out the message of just how valuable, how powerful science is and how important it is—how it’s more important to lives of nonscientists than to the job of scientists.”

The people marching on Saturday care about science, and understand its importance in climate change research and modern medicine. But the fact is, many Americans are science illiterate; the majority cannot name a single living scientist. So here are several reasons we need the science Trump wants to cut.

You need science to know what to wear in the morning.

Daily weather forecasts rely on satellites, and most satellites are launched and operated by the National Oceanic and Atmospheric Administration (NOAA), according to Rick Spinrad, NOAA’s chief scientist during the Obama administration. The White House has proposed a $510 million cut to NOAA’s $2.3 billion satellite division.



That’s a lot of money to cut from a program that, to be fair, does far more than tell us whether it’s a good day to wear a sundress. Forecasting helps cities and states prepare for weather disasters, thereby preventing millions in economic damage. Airlines rely on accurate forecasts to provide safe travel. NOAA’s own research suggests Americans gain $31.5 billion in socioeconomic benefits from weather forecasts each year.