Just days into his new term, Donald Trump's administration has begun a sweeping purge of climate and health data from federal websites, sparking widespread concern among researchers, scientists, and environmental advocates. Key resources, including the Centers for Disease Control and Prevention's (CDC) social vulnerability index and environmental justice index, have already been taken down, with more expected to follow.

The CDC's social vulnerability index, which was developed in 2007, provides critical data on demographic and socioeconomic factors that affect health risks, including poverty, race, and ethnicity. The environmental justice index, launched in 2022, helps identify communities disproportionately affected by pollution. Both tools have been removed from the CDC's website within the past week, according to reports.

Researchers have been archiving government websites for months in anticipation of the purge, a typical practice during presidential transitions. However, the urgency was heightened with Trump's return to office, given his previous efforts to dismantle climate and environmental policies. During his first term, access to nearly 20% of the Environmental Protection Agency's website was removed, and similar moves are now underway.

The purge is part of a broader effort by the Trump administration to undo previous administrations' work on climate change, racial equity, and gender identity. In an executive order, Trump claimed that "diversity, equity, and inclusion" (DEI) has "corrupted" government institutions, and that "climate extremism has exploded inflation and overburdened businesses with regulation."

In addition to the CDC, other federal agencies, such as the US Department of Transportation, have also removed webpages related to climate change and DEI. The department's "priorities" website has taken down pages on both "climate and sustainability" and "equity." An internal memo sent this week instructed USDOT operating administrations to identify and ultimately "terminate" Biden-era activities relating to climate change and DEI.

Furthermore, information on HIV and AIDS has been removed from the US President's Emergency Plan for Aids Relief (PEPFAR) website, which has been in operation since 2003 and has helped over 20.6 million people access antiretroviral therapy in 2024 alone.

Fortunately, initiatives such as the End of Term Web Archive project and the Environmental Data and Governance Initiative (EDGI) have been working to archive and preserve government data, including the CDC's social vulnerability index and environmental justice index. However, even with archived data, the lack of updates poses significant challenges for researchers and policymakers.

"Any dataset has a lifespan of utility," notes Dan Pisut, senior principal engineer at GIS software company Esri. "Aging datasets might not fully represent what's actually happening on the ground, so people have to be careful about how they use them." While archived data is better than nothing, the limitations of outdated information could have far-reaching consequences for public health and environmental policy.

As the Trump administration continues its data purge, concerns about the erosion of critical resources and the undermining of scientific research are growing. The implications of this purge will be closely watched, and the tech community will be following developments closely.