April 22 is Earth Day, an international holiday dedicated to the environment. This year, Earth Day is kicking off an “Earth Week” culminating in the People’s Climate March on April 29. And, on Earth Day itself, scientists will take to the street in the March for Science.

Trump’s attacks on the environment have been closely entwined with attacks on science itself. Trump himself believes climate change is a hoax and has picked a climate change denier, Scott Pruitt, to head the Environmental Protection Agency (EPA). William Happer, Trump’s proposed science adviser has deemed that climate science, as a whole, is “really more like a cult.” The Trump administration has moved to freeze grants for scientific research and has placed gag orders on scientists working for the EPA and USDA. The conflict between Trump and the scientific community intensified when Trump temporarily banned the National Park Service from Twitter.

But scientists are fighting back. In December of last year, 400 scientists at the American Geophysical Union meeting in San Francisco demonstrated against Trump’s attacks on science. Scientists working for government agency have been moving to save the climate data currently on federal sites, before Trump has a chance to take it down. And, with the March for Science, things are getting bigger. Starting as a Facebook group of 200 members, it ballooned to 300,000 members in the span of a week. Invigorated by other anti-Trump protests around women’s rights and immigrant rights, we could be seeing the biggest fightback among scientists in decades.

Under capitalism, scientists are trained to see themselves as passive observers of nature. Political engagement is seen as ideological interference in the scientific process. The mere fact that scientists feel compelled to take to the streets is forcing scientists to challenge that incorrect notion. And it has provoked debate within the scientific community itself. Sylvester James Gates, the theoretical physicist and former science adviser to the Obama administration, has attacked the March for Science on the grounds that “such a politically charged event might send a message to the public that scientists are driven by ideology more than by evidence” (Bloomberg.com, 3/7/2017).

But science is, and has always been, political. For example, Galileo was persecuted by the Catholic Church in the Middle Ages for challenging church doctrine. He was charged with “heresy” for declaring that the Earth revolved around the Sun. Science isn’t simply about studying nature and accumulating knowledge, but about using that knowledge for the betterment of humanity. While science has been used to build the atomic bomb, radical scientists also played a leading role in the anti-nuclear movement. And with our very climate in danger, scientists are forced to be political to help find a way out.

Defend scientists and climate change science from attacks from the oil industry, Trump and Republicans.

Hands off the EPA. Use climate-change science to guide policy not right-wing ideologies. No funding cuts for climate research.