On Wednesday, presidential candidate Elizabeth Warren introduced the “Defense Climate Resiliency and Readiness Act” in a Twitter thread and an accompanying Medium post. The thrust of the bill, according to the Medium post, is for the military to “achieve net zero carbon emissions for all its non-combat bases and infrastructure by 2030.”

Warren proposes a couple of ways to pay for this, including a fee on military contractors for any greenhouse gas emissions and direct federal funding. All of the money, she said, would be reinvested toward building energy-efficient infrastructure.

“In short, climate change is real, it is worsening by the day, and it is undermining our military readiness,” Warren’s post reads. “And instead of meeting this threat head-on, Washington is ignoring it—and making it worse.”

Besides Warren, not one presidential candidate has proposed targeting the emissions from the U.S. military, which is a huge problem. The Union of Concerned Scientists has said that the U.S. military is the "largest institutional consumer of oil in the world," burning 85 million barrels of oil annually. As Warren said in her Medium post, it’s the “single largest government consumer of energy.”

The International Panel on Climate Change’s 1.5 Degree Report states that massive societal change will be necessary to keep global warming below the worst possible levels. So anything that requires the military to emit less, and creates a tangible pathway to continuing to emit less over time, is worth exploring.

However, it’s worth pushing back on the idea that climate change should be understood as a threat to “military readiness,” and a threat to national security. When the military frames climate change this way, it says that climate change-driven conflict warranting a militarized response is inevitable. The military defines this conflict as "disputes over refugees and resources," which is a way of saying that refugees are a danger to the U.S.

Warren didn't invent the rhetoric of climate change as a national security threat. It’s a line of reasoning that is pitched by the military itself and has been repeated by the media. It's an appealing argument. Centrist or right-leaning Americans often understand climate change as a moderate problem: sure, climate change may be real, but it’s probably not as severe as the overwhelming consensus of scientists have stated. This sentiment probably comes from a combination of Repulican practices of actively undermining climate scientists, and mistrust in the elite institutions that produce these scientists. But if concern about climate change comes from the military—a hallowed institution among centrists and Republicans specifically—these concerns have newfound power. Meanwhile, on the left, the thinking goes: we need to reach across the aisle to combat climate change, and maybe the military is the institution that can make the reach.

The 2014 Climate Change Adaptation Roadmap cited by Warren in her Medium post—like most military reports discussing risks due to climate change—makes two main points:

One, military bases and infrastructure are at risk due to climate change-related extreme weather events, like wildfires and flash floods, and long-term environmental changes like sea level rise.

Two, critically, other nations will become unstable and become a problem to the U.S.

“The impacts of climate change may cause instability in other countries by impairing access to food and water, damaging infrastructure, spreading disease, uprooting and displacing large numbers of people, compelling mass migration, interrupting commercial activity, or restricting electricity availability,” the report says.

The report also says that “already-fragile” governments will be undermined, and that avenues for terrorism and extremism can open up.

The second part of military reports like the 2014 climate roadmap are crucial: the military characterizes climate change as something that makes other countries unstable and puts the military at risk. According to the military, climate change is a “threat multiplier” in a scenario where the threat is people from other countries, and the threatened are the U.S. and its military.

Historically, fear of “instability” has been used to justify military intervention in countries like Iraq and Syria. In the context of climate change, instability becomes a rallying cry the military can use to justify conflict in regions that will be vulnerable because of climate change. After all, this is the primary purpose of the military specifically: to define and engage in conflict.

So when climate change is framed as a threat to “military readiness,” this means that the response to climate change is maintaining or intensifying ongoing military operations. When climate change is also framed as a “national security threat,” the targets of this response are defined the populations named in the 2014 Climate Change Adaptation Roadmap: migrants, refugees, vulnerable people from other countries. In other words, we should expect state-sanctioned violence and asylum denials to intensify and intensify in response to climate change-driven migration.

We’re already seeing this play out on our borders. Consider how the U.S. treats migrants from Mexico, Guatemala, Honduras, El Salvador, and other countries in central America: these migrants are defined as a threat to U.S. national security, and a consequence of increasingly radical policy has been routine violence. To name just a few examples, U.S. border patrol agents shot tear gas at people on the Mexico-side of the border last November. Asylum seekers are held in U.S. detention centers, where they are subject to unsanitary conditions, limited food, and are routinely sexually assaulted. This past week, a two-year-old in a US detention center died.

It’s also worth focusing on the situation in Syria, a conflict that some researchers, and representatives from the U.S. military have argued was driven or intensified by a climate change-driven drought. The U.S. has heavily and violently intervened in the country’s civil war for years. The aftermath has left thousands of migrants, and the U.S. admitted just 62 of them in 2018.

Betsy Hartmann, a professor emerita of development studies at Hampshire College, pushed back against defining climate change as a national security threat in a 2010 article for the Journal of International Development. Hartmann argues that the U.S. military portrays Africa, in particular, as a region that will become more prone to terrorism due to climate change-driven instability. But in saying this, the military defines Africa as “ungovernable,” and creates the rhetorical foundation to justify intervention.

“Spinning climate change as a security threat is likely to undermine, rather than strengthen, serious efforts to link climate change mitigation and adaptation to development efforts that reduce poverty and promote equity,” Hartmann writes. “Playing with fear is like playing with fire. You cannot be sure exactly where it will spread.”

Similarly, the Swedish government's Commission on Climate Change and Development said in a 2009 report, “Framing migration as a threat leads to policies that do little to control migration, but which do limit the benefits of migration to migrants, their communities of origin, and their host communities.”

But in the U.S., fears of climate change as a national security threat remain pervasive.

“We don’t have to choose between a green military and an effective one," Warren wrote in her Medium post. “Together, we can work with our military to fight climate change — and win,” she added.

Of course, emissions from the military should go down, and candidates like Warren and Bernie Sanders have also called to cut overall Department of Defense spending. But climate change is not a “fight” for the military. The military’s explanation of climate change conceives of a world of us versus the other, Americans versus migrants and non-Americans. This polarized understanding of who is a threat and who is threatened is setting the stage for inevitable conflict and violence.