Editor-in-Chief Laura Helmuth said President Donald Trump’s administration was far worse for the scientific community than the magazine had feared.
The magazine’s endorsement was posted online on Tuesday, a day after Mr Trump questioned the science of climate change in relation to California’s wildfires.
Ms Helmuth said the timing was coincidental and the editorial was written during the past two months.
Donald Trump has basically damaged the United States and its people because he rejects evidence and science
Scientific American said “the evidence and the science show that Donald Trump has basically damaged the United States and its people because he rejects evidence and science”.
The editorial by senior editor Josh Fischman sharply condemned Mr Trump for his handling of the coronavirus pandemic. The magazine criticised Mr Trump for seeking cutbacks in scientific funding and hobbling the US response to climate change.
Mr Biden, the magazine said, “has a record of following the data and being guided by science”.
There was no immediate reply to a request for comment from the Trump campaign.
There has been some push back, with some commentators questioning whether the magazine had stepped out of its territory.
But Ms Helmuth said the magazine had not ignored politics in its long past. The Atomic Energy Commission burned 3,000 copies of an issue in the 1950s because of its stance against the hydrogen bomb.
The magazine has been running more opinion pieces lately, and in 2016 wrote an editorial questioning Mr Trump’s fitness to be president, although it did not endorse Hillary Clinton.
“Part of our magazine’s mission is to show people how the world works – whether it’s black holes, evolution, viruses, or systemic racism,” Ms Helmuth said.
“We felt it was our duty as part of that mission to warn people that Trump has been disastrous for research, science, health and the environment.”
The magazine hopes it does not have to make a presidential endorsement again, she said.
On Monday, Trump was confronted during the California briefing about a need to address climate change, and he said that the Earth would get cooler.
“I wish science agreed with you,” responded Wade Crowfoot, secretary of the California Natural Resources Agency.
“Well, I don’t think science knows, actually,” the president said.
