In a forthcoming article in the Harvard Environmental Law Review, I argue that climate change is one of the most pressing national security issues facing the United States and the world. Climate change is not simply an environmental issue. It also accelerates existing national security threats, acting as both a threat accelerant and catalyst for conflict. And the peer-reviewed science is now refined as to be essentially irrefutable. Human activity is causing climate change and recent advances in climate attribution science showcase the causal linkage between extreme weather events and climactic change. Climate change will increase the intensity and frequency of droughts, wildfires, and extreme weather, serving as the defining factor of our “climate-security century.” Denying these widespread advances in climate science undermines national security, and we shouldn’t be afraid to say so.

Just as climate change is destabilizing the physical environment, it is also beginning to destabilize the legal landscape while bringing together different areas of law in new and surprising ways. We need innovative legal and policy solutions to tackle the “super wicked” problems caused by climate change. In what follows, I highlight three interrelated climate-security questions that are in need of answers.

  1. How does Climate Security Affect Climate Mitigation Efforts?

For starters, climate change is forcing us to look at the relationship between environmental law and national security law with fresh eyes. Historically, environmental law has had somewhat of an adversarial relationship with national security law. For example, numerous environmental laws include exemptions for military activities when the president determines that they are in the “national security interest.” This includes the Clean Air Act, the key statute that regulates greenhouse gas (GHG) emissions within the United States.

But what if excessive GHG emissions are the cause of the underlying national security threat — a point made all-too clear by the most recent National Climate Assessment? In the climate-security context, what was once in conflict may well be aligned as we look to preserve our common future from all threats, however defined. Indeed, climate change demands greater environmental protections to reduce GHG emissions. And we already know that the U.S. military is an enormous emitter of carbon and other GHG emissions. In fact, Brown University’s Costs of War Project recently estimated that the U.S. Department of Defense emitted more greenhouse gas emissions into the atmosphere than many industrialized nations, such as Sweden and Denmark. As we think broadly about future climate mitigation strategies, we must take into account all GHG emissions, regardless of their source.

  1. Is Climate Change a National Emergency?

Paradoxically, President Donald Trump’s controversial declaration of a national emergency at the southern border may have given climate change activists a possible tool to address climate change. As the Trump emergency border declaration painfully demonstrated, what constitutes an “emergency” under the 1976 National Emergencies Act is not well-defined in statute, and Trump is testing that boundary. Further, the Supreme Court will afford great deference to the president when making an emergency determination. The outer limits of what constitutes an emergency remain to be seen by the Supreme Court under Chief Justice John Roberts — could a climate emergency count?

Obviously, any climate emergency discussion would require a change in who occupies the Oval Office. Nevertheless, if a future president declared climate change a national emergency, she could potentially invoke already-delegated powers at her disposal to slow the rate of domestic fossil fuel extraction and lower our collective GHG emissions.

To be clear, we need domestic climate change legislation that prices carbon and all GHG emissions appropriately. This would fully honor the legislative process and would afford the highest amount of democratic legitimacy. Whether this is a carbon tax or a cap-and-trade model is less important; what matters is that we actually pay carbon’s true cost. Every day that goes by without meaningful climate action amounts to a de facto climate tax that is “hidden, unfair, and ever-increasing.” Yet in the absence of any climate political action in the face of overwhelming science, what are we to do?

In the face climate intransigence, the “break glass in case of emergency” approach will be an increasingly appealing option to a growing number of activists and some politicians. Indeed, there is already a growing segment of activists and politicians who are eager for any action on climate change in whatever form it may take. And so, they are embracing “emergency language” in their approach. For example, while it does not actuate legal authorities, Sen. Bernie Sanders (I-Vt.) currently has a Senate Resolution declaring climate change a national emergency, in the hopes of raising awareness on the issue. Could this be setting the stage for a future climate emergency declaration under the National Emergencies Act?

  1. What are the Opportunities and Risks in Conceptualizing Climate Change as a National Security Issue?

National security, military, and intelligence professionals are solution-oriented information brokers who bring credibility and expertise to an increasingly complex climate discussion. Within the national security community, there is already a deep culture of planning that is designed to counter emerging threats. This security planning mindset is tailor-made to find workable solutions and tackle the “known-unknowns” inherent to the problem of climate change. We know that climate change is transforming our physical environment and the military’s operational environment in fundamental ways. We also know that climate change will exacerbate existing environmental stressors and the developing world will be most affected by climate change. But we don’t know with precision how, exactly, the melting ice caps will impact sea-level rise, nor do we know where food, drought, and water insecurity will spark the next conflict or refugee crisis. Nevertheless, we must plan accordingly with the best information, intelligence, and science before us, focusing on the most vulnerable parts of the nation and the world.

But having a broad conception of what amounts to a national security concern comes with its own potential pitfalls that we must not dismiss. The current president has been all too quick to broaden his own definition of what constitutes national security to encompass trade, immigration, and other issues. In doing so, national security can serve as a blunt instrument wielded by the executive branch, bypassing the democratic process. Indeed, recall that Secretary of Energy Rick Perry invoked a national security rationale in defending the Trump administration’s decision to continue to operate coal-fired power plants. Put simply, we must be cognizant of not having too capacious a definition of what constitutes “national security.” If everything is national security, nothing is national security. And this could continue the trend of centralized decision-making in the executive branch at the expense of the legislative process.

So, Where Do We Go from Here?

The answers to these three questions will become more important over time, particularly if our current climate paralysis continues. As my colleague Cary Coglianese has aptly described, climate change is a “collective action problem on steroids.” The stakes couldn’t be higher, yet the United States has been absent on both the international and domestic climate stage, stepping away from the Paris Climate Accord and largely ignoring the alarm bells sounded by the scientific and national security communities for years.

The small silver lining: Climate change may well be serving an important purpose. I argue in the Harvard Environmental Law Review that climate change sheds light on shared values between the environmental and national security communities that have always existed since our nation’s founding, albeit below the surface. After all, both environmentalists and national security professionals ultimately seek to safeguard the security, health, and welfare of every citizen. In its most fundamental ways, what is good for the environment is good for national security.

Finally, it is readily apparent that the costs for climate denialism are simply too costly to pay anymore. Both parties must acknowledge that climate change is fundamentally a scientific problem in need of a political solution. Not vice versa. As Greta Thunberg leads a worldwide climate strike today and the world prepares for a historic Climate Week in New York City next week, we must be clear-eyed about climate change’s underlying threats and what an increasingly diverse group of youthful crusaders, scientists, and national security professionals scientific are telling us.

Image: Teenagers and students take part in a climate protest outside the White House in Washington on September 13, 2019. Swedish environment activist Greta Thunberg, 16, has spurred teenagers and students around the world to strike from school every Friday under the rallying cry “Fridays for future” to call on adults to act now to save the planet. Photo by Nicholas Kamm/AFP/Getty Images