The Environmental Protection Agency on Thursday relaunched a webpage dedicated to climate change that had gone dark under President Donald Trump, who frequently dismissed the scientific consensus that humans are warming the planet.

The restoration of the climate website comes four years after the Trump administration took down much of the EPA’s digital presence that explained global warming and why it is worth fighting.

To underscore the reversal, EPA Administrator Michael Regan, who was confirmed by the Senate last week, declared in a video message posted on the new website: “Combating climate change, it’s not optional, it’s essential at EPA.”

As the nation’s chief protector of clean air and water, the EPA is poised to play a central role in President Biden’s efforts to eliminate carbon pollution from the power sector by 2035 and the rest of the U.S. economy by 2050. Meeting those ambitious goals will almost certainly require a new suite of regulations from the EPA curbing greenhouse gas emissions from cars, power plants, landfills, factories and a host of other sources.

The new climate site, with English and Spanish versions, is sparsely populated and promises “more content to come.” But environmental advocacy groups are already praising its return for the early symbolic shift it represents in federal climate policy.

“Only when we’re armed with the facts about what we face now and in the coming years — and have information on what we can do to make a difference on climate change — can we make the best decisions,” Andrea McGimsey, senior director for Environment America’s “global warming solutions” campaign, said in a statement.

After Trump’s 2016 election as president, some environmental activists and scientists worried that the president’s dismissal of climate change and his appointment of like-minded agency heads could imperil federal scientific data.

They began to feverishly copy and archive large sets of public information on everything from historical temperature records to data about droughts and floods, as well as climate projection models. The efforts spanned a “guerrilla archiving” event in Toronto to meetings at the University of Pennsylvania, where researchers mapped out how to download as much federal data as possible before Trump took office.

Those fears that the Trump administration would simply delete existing data or forbid any kind of climate-related research largely did not come to pass. But the administration did downplay references to climate change in many federal reports and policies, and it was never an issue of priority.

Among former EPA administrator Scott Pruitt’s first actions in office in 2017 was removing the agency’s long-standing climate webpage, which had existed for about two decades, as well as other information on the Barack Obama administration’s Clean Power Plan. The Trump administration did maintain a publicly available archive of how the page looked on the day before his inauguration.

The climate Web pages of some other agencies, notably NASA and the National Oceanic and Atmospheric Administration, remained largely intact under Trump. Yet across federal agencies, the use of the term “climate change” declined by almost 40 percent between 2016 and 2020, according to the Environmental Data and Governance Initiative, a nonprofit that tracked the changes.

“We are relieved to see that the EPA is now actually going to post information about climate change on its website — again,” Dominique Browning, co-founder of the activist group Moms Clean Air Force, said in a statement Thursday. “The site was removed by a denier administration, and their denial is endangering all of us. It’s time to face reality.”

Andrew Freedman contributed to this report.