One of Dr. Rod Schoonover's jobs with the State Department's Bureau of Intelligence and Research was to understand the threats the global climate emergency poses to American national security. As a scientist, he pored over 25 years of papers, reports and publications as part of his analysis.

When his bureau was asked to share these threats with the House Permanent Select Committee on Intelligence, the testimony was blocked by the White House. Members of the Trump administration claimed that it included "climate alarm propaganda" that did not reflect their views on the issue.

While Schoonover was ultimately permitted to provide a five-minute oral summary of the testimony, the written document was kept off the permanent Congressional record of the hearing.

Last week—in his first public event since resigning his position in protest—Schoonover was interviewed by World Resources Institute Distinguished Senior Fellow Andrew Light.

When Light asked if the way the White House handled his work was a "suppression of science," Schoonover replied, "It felt like it. Is it a pattern? Yeah, it seems like it."

For National Security, Climate Change is a 'Threat Multiplier'

For decades, the U.S. defense community has been concerned (PDF) about the implications of climate change on national and global security. Schoonover explained that while part of this interest stems from concern about the security of military bases themselves (from threats like sea level rise, for example), the larger concern is about how it will impact geopolitical tensions.

"It's critical for the intelligence community to understand the evolving threat landscape presented to the United States and its allies, and of course that includes a changing climate," he said.

As the written testimony Schoonover's bureau submitted to Congress attests, "With increased pressure from climate change existing social and political structures will come under greater strain, which could deepen grievances and stoke tensions … The consequences will likely be severe enough in some instances to compel international reaction, including from the United States."

For example, a three-year drought in Syria—already a dry country—is thought to have escalated tensions leading to the ongoing conflict through crop failure and subsequent mass migration of farmers to cities.

In some small island nations, on the other hand, sea level rise is infiltrating freshwater aquifers, which puts further pressure on already limited freshwater supplies and threatens the very survival of island residents, a reality that could lead to political unrest that escalates beyond national borders.

Climate Change Impacts Go Way Beyond Extreme Weather—and We're Still Figuring Out How

Schoonover observed that while most research on the links between climate change and security focuses on extreme weather, there are many other stresses that may be equally important but not as well studied. The range of impacts spurred by higher temperatures is just one example.

"When you increase the temperature, you're not only making it hot to human beings, you're changing a lot of the biochemical, biophysical, biological, ecological systems in the biosphere … and quite honestly, we don't understand that well enough." A global temperature increase of just a degree or two could manifest in human lives in countless ways: "through fisheries, through agriculture, through changing patterns of disease-carrying organisms, changes in the ecological food system, oceanic oxygen content."

Climate Change 'Surprises' Are Inevitable

We may not know everything about how climate change is affecting and will affect our planet, but we know enough to know there will be climate "surprises"— which Schoonover defines as low-probability, high-impact events, the type of events that national security experts are trained to prepare for.

He cites a recent example in the Caribbean, where sargassum seaweed—once a natural part of a balanced ecosystem—is now choking the region's beaches, with tons washing up every day and causing health problems for beachgoers. "It is fueled by fertilizer runoff from Brazil and warming ocean conditions … And these small island nations in the Caribbean consider this to be a national security threat—not just a nuisance—because of the impact on tourism, on economic vitality. It is strangling the resources for a lot of these countries."

'Our National Security Rests on Scientific Integrity'

When asked about the administration's claim that he was being alarmist with his testimony, Schoonover didn't mince words. "There's what mainstream science says, and then there's what mainstream science doesn't say." He emphasized that his remarks on the subject are not the agenda of one individual, but rather they reflect the scientific evidence he's compiled while reviewing countless scientific articles and assessments on climate change. "Our national security rests on scientific integrity."

Schoonover's conviction about this issue motivated him to publish an opinion piece in the New York Times last week. But ultimately, he hopes people will focus less on the White House's response to the testimony prepared by his bureau at the State Department and more on the climate and security connection.

"My hope is that I become less of a story and we return to the substantive issues of climate change and national security, because that's way more important than any individual — including me."