Ten years ago, I left my job as a tenured university professor to work as an intelligence analyst for the federal government, primarily in the State Department but with an intervening tour at the National Intelligence Council. My focus was on the impact of environmental and climate change on national security, a growing concern of the military and intelligence communities. It was important work. Two words that national security professionals abhor are uncertainty and surprise, and there’s no question that the changing climate promises ample amounts of both.

I always appreciated the apolitical nature of the work. Our job in the State Department’s Bureau of Intelligence and Research was to generate intelligence analysis buttressed by the best information available, without regard to political considerations. And although I was uncomfortable with some policies of the Trump administration, no one had ever tried to influence my work or conclusions.

That changed last month, when the White House blocked the submission of my bureau’s written testimony on the national security implications of climate change to the House Permanent Select Committee on Intelligence. The stated reason was that the scientific foundation of the analysis did not comport with the administration’s position on climate change.

After an extended exchange between officials at the White House and the State Department, at the 11th hour I was permitted to appear at the hearing and give a five-minute summary of the 11-page testimony. However, Congress was deprived of the full analysis, including the scientific baseline from which it was drawn. Perhaps most important, this written testimony on a critical topic was never entered into the official record.

The bottom line of written testimony was this: “Climate change will have wide-ranging implications for U.S. national security over the next 20 years.” In developing this assessment, I drew from peer-reviewed scientific studies and findings of the government’s own scientists. This conclusion was hardly new. The intelligence community has repeatedly warned of the dangers that climate change poses to national security. Early this year, for instance, Dan Coats, the director of national intelligence, warned in the annual “Worldwide Threat Assessment,” “Global environmental and ecological degradation, as well as climate change, are likely to fuel competition for resources, economic distress, and social discontent through 2019 and beyond.” (On Sunday, President Trump announced that Mr. Coats would step down shortly, to be replaced by one of his biggest defenders, Representative John Ratcliffe, a Texas Republican.)

In blocking the submission of the written testimony, the White House trampled not only on the scientific integrity of the assessment but also on the analytic independence of an arm of the intelligence community. That’s why I recently resigned from the job I considered a sacred duty, and the institution I loved.

As a tenured professor trained in physics and chemistry, I was admittedly an unusual fit for the intelligence community. I likely would never have considered the move if not for a program run by the American Association for the Advancement of Science that connects Ph.D. scientists to roles within the U.S. government to shape and inform policy. I found a home in the Bureau of Intelligence and Research, the oldest civilian intelligence agency in the government and well known for its history of analytic sharpness and courageous dissent.

Science has long intersected with intelligence analysis. Indeed it would be difficult if not impossible to elucidate the ramifications of nuclear materials, near-earth objects, infectious diseases and many other pressing national security concerns without a deep understanding of the foundational science of each. This, too, applies to climate change.

Decades of scientific measurements have established that global temperatures are increasing and ocean waters are acidifying. These changes produce shifts in a vast number of earth system processes: in the atmosphere, ocean, freshwater, soil, ice masses, permafrost and organisms making up the biosphere. Some effects are well known, like increased frequency and intensity of heat waves and droughts, and rising sea levels. Others are less familiar, like decreasing oceanic oxygen levels and the redistribution of species.

These events do not arise in isolation but combine with existing social and political conditions and can disrupt societies and nations. They harm people directly or degrade the social, political, economic, agricultural, ecological or infrastructural systems that support them.

With these environmental changes we should expect disruptions to global water and food security, reduced economic security and weakened livelihoods, worsened human and animal health, and risks to the global supply chain on which the United States and its partners depend. Political instability, heightened tensions over resources, climate-linked humanitarian crises and adverse effects to militaries in some places are likely to increase. Migration will probably increase both within and between nations, with sociopolitical and resource implications already becoming clear.

Despite the increased politicization of climate change, I embraced the opportunity to participate in an unclassified congressional hearing on such an important matter. In particular, I welcomed the chance to engage Republican members of Congress on the topic because of the party’s historically strong support of other science and technology issues. Previous closed-door discussions persuaded me that at least some Republican lawmakers were open to the argument that climate change was a national security concern. I believe that once one accepts that global temperatures are increasing, a fact that only the most ardent climate disbeliever rejects, the case for that fact’s relevance to nation security directly follows.

When I joined the government in 2009, leadership was generally receptive to environmental security analysis. After the administration changed in 2017, my job was arguably even more important because of the skepticism within the Trump administrative over climate change. The intelligence community tries to deliver objective truth to decision makers — truth that persists irrespective of who occupies the White House.

I take great pride in the many positive and productive interactions I had with senior officials in my 30 months in the Trump administration. But the decision to block the written testimony is another example of a well-established pattern in the Trump administration of undercutting evidence that contradicts its policy positions.

Beyond obstructing science, this action also undermined the analytic independence of a major element of the intelligence community. When a White House can shape or suppress intelligence analysis that it deems out of line with its political messaging, then the intelligence community has no true analytic independence. I believe such acts weaken our nation.

My last day on the job was July 12. In the weeks since the hearing I came to understand that there was little left for me to achieve in my position. More than most officers in the intelligence community, I interacted often with the public in discussions of environmental security issues. After the experiences of the prior two months, I wondered whether I could continue public engagements without being tainted by questions about my own analytic independence.

Grappling with the implications of climate change and biodiversity loss, the two primary security concerns I’m focused on, is too important to me to wait around for a possible change on these issues in a future administration. We need to better understand and anticipate the challenges facing the nation and its partners. Whatever my next step might be, I believe these issues remain critical, and I will try to continue this work going forward.

Rod Schoonover was, until recently, a senior analyst in Bureau of Intelligence and Research at the State Department. He also worked as director of environment and natural resources at the National Intelligence Council and was a professor of chemistry and biochemistry at California Polytechnic State University, San Luis Obispo.