Climate Change Is National Security: Presidential Leadership Makes A Difference

American Security Project


A changing climate -- rising sea levels, melting sea ice, worsening storms, extreme heat, and drought -- threatens America's military infrastructure and readiness, fragile governments and stability, and the US' position as a global leader. Despite the risks, the US has only intermittently recognized climate change as a threat in the government's national security strategic assessments.

Climate Change: A Threat to National Security

Climate change impacts US national security interests in a myriad of ways.

First, it impacts the physical military infrastructure and readiness. For example, the Norfolk Naval Base is an at-risk military base due to the rising sea level. And, extreme heat impacts readiness by limiting troops' ability to train outdoors and pilots' ability to fly training missions.

Second, climate change has been described as a "threat multiplier." For instance, crop failure and food insecurity may force people to migrate in search of food and jobs, and if migrants are unable to find food and jobs, or take jobs away from more established residents, protests may break out. If this happens in places where the government is fragile, such civil unrest may lead to political instability and ultimately a failed state. Instability and failed states threaten US national security interests.

Third, it also plays a role in great power competition. In recent years, the US has withdrawn from its position as a global leader on climate change and its ability to exert influence on a variety of issues is threatened. For example, as Arctic sea ice continues to melt, new oceanic pathways for trade, resource mining, geopolitics, and potential military conflict are opening up. Russia's stake in the region has been of particular attention in recent years, as they have a powerful icebreaker fleet and the most maritime claims under the UN Law of the Sea Treaty. Additionally, China has labeled itself a "near-Arctic state" and has more icebreakers than the US.

ProPublica - How the Climate Crisis Will Force A Massive American Climate Migration, November 2020.

Climate Change: Inside Past Administrations' National Security Strategies

1. Bush Administration

September 11th happened less than a year into President Bush's first term, and the World on Terror dominated President Bush's tenure. As such, Bush's National Securities Strategies (NSS) from 2002 and 2006 placed a strong emphasis on combatting terrorism. While there is no use of the phrase "climate change" in either NSS, there are references to emissions reductions and the importance of limiting human impact on the climate.

In the 2002 NSS, there is a subsection, titled "Enhance energy security," that references clean energy generation:

Economic growth should be accompanied by global efforts to stabilize greenhouse gas concentrations associated with this growth, containing them at a level that prevents dangerous human interference with the global climate.

This language recognizes the role humans play in the global climate and the importance of controlling our emissions. The NSS suggests a few strategies with which to achieve these reductions including a cap-and-trade system, improved emissions standards, and regulations, and assisting developing countries with their growth to mitigate global emissions.

"Unlike Bush, both of President Obama's National Securities Strategies (2010 and 2015) link climate change to US national security interests."

The 2006 NSS similarly maintains a strong focus on the Terrorism; however, the section on enhancing energy security and clean development references efforts toward international cooperation to address climate change:

[The US] joined with Australia, China, India, Japan, and the [Republic of Korea] in forming the Asia-Pacific Partnership for Clean Development and Climate to accelerate deployment of clean technologies to enhance energy security, reduce poverty, and reduce pollution.

In a following discussion on the unsustainable reliance on foreign oil, the report suggests strategies for increasing our energy security, including investment in "revolutionary solar and wind technologies [as well as] clean, safe nuclear energy;" and developing "clean coal and … zero-emission coal-fired plants."

Ultimately, neither of Bush's NSSs directly identify climate change as a threat to US national security interests -- rather, emphasizing the need to find economic growth strategies that do not increase global carbon emissions and bolster America's energy security.

"In stark contrast to his predecessors, President Trump removed any mention of climate change from his 2017 National Securities Strategies ... Similar to Bush's NSS reports, however, the need to bolster Americas energy security and the connection to economic growth is referenced…"

US Naval Station Norfolk (Photo: Ian Swoveland).

2. Obama Administration

Unlike Bush, both of President Obama's NSSs (2010 and 2015) link climate change to US national security interests. The 2010 NSS makes the direct connection between US national security interests and climate change:

The danger from climate change is real, urgent, and severe… a warming planet will lead to new conflicts… and the degradation of land across the globe. The United States will therefore confront climate change based upon clear guidance from the science, and in cooperation with all nations.

This NSS also emphasizes the need to confront the climate threat through international cooperation: "…an effective, international effort in which all major economies commit to ambitious national action to reduce their emissions."

The Obama emphasis on climate change helped pave the way for the 2015 Paris Climate Accords: "…we are working toward an ambitious new global climate change agreement to shape standards for prevention, preparedness, and response over the next decade."

The 2015 NSS identifies climate change as one of the top eight most important national security threats facing the US:

Climate change is an urgent and growing threat to our national security… The present day effects of climate change are being felt from the Arctic to the Midwest. Increased sea levels… threaten coastal regions, infrastructure, and property. In turn, the global economy suffers, compounding the growing costs of preparing and restoring infrastructure.

Overall, Obama's National Security Strategies go beyond Bush's in their recognition of both the threat climate change poses, and efforts to mitigate it.

General Stan McCrystal and John Kerry Instagram Live conversation on national security and the climate crisis, broadcasted on October 27, 2020.

"While President Biden has yet to issue National Securities Strategies, it is clear he believes climate change should be a national security priority ... during his first weeks in office Biden signed three Executive Orders and recommitted the US to the Paris Climate Agreement…"

3. Trump Administration

In stark contrast to his predecessors, President Trump removed any mention of climate change from his 2017 NSS. Trump's NSS mentions Middle Eastern terrorism, rogue nuclear states, unfair trade practices, US immigration policies, and "unfair burden-sharing with our allies” as threats to national security, but not explicitly climate change."

Similar to Bush's NSS reports, however, the need to bolster America’s energy security and the connection to economic growth is referenced:

America's central position in the global energy system as a leading producer, consumer, and innovator, ensures that markets are free and US infrastructure is resilient and secure. It ensures that access to energy is diversified, and recognizes the importance of environmental stewardship… Unleashing these abundant energy resources -- coal, natural gas, petroleum, renewables, and nuclear -- stimulates the economy and builds a foundation for future growth.

Additionally, there is a brief mention of emissions: "The United States will remain a global leader in reducing traditional pollution, as well as greenhouse gases, while expanding our economy."

Beyond the references to energy security and reducing pollution and emissions, there are no references to climate change and its role in US' regional security, operational security, or great power competition strategies. Ultimately, Trump's NSS fails to recognize the connection between climate change and US national security.

4. Biden Administration

While President Biden has yet to issue a NSS, it is clear he believes climate change should be a national security priority. Prior to his inauguration, Biden announced his intent to appoint Secretary John Kerry as the Special President Envoy for Climate, a newly created position with a seat on the National Security Council. Furthermore, during his first weeks in office, President Biden signed three Executive Orders (EOs) and recommitted the US to the Paris Climate Agreement, clearly demonstrating the administration's recognition of climate as a national security issue.

The first EO, signed on January 20, 2021, directs the heads of all agencies to review all existing regulations, orders, guidance documents, and policies, and update as needed, to ensure that all documents are guided by the best science available.

The second EO, signed on January 27, 2021, identifies climate considerations as an essential element of US foreign and national security. Specifically, the EO:

  • Requests a National Intelligence Estimate (NIE) on the national and economic security impacts of climate change;
  • Directs the Secretary of Defense and Chairman of the Joint Chiefs of Staff to consider the security implications of climate change in the "National Defense Strategy, Defense Planning Guidance, Chairman's Risk Assessment, and other relevant strategy, planning, and programming documents and processes;"
  • Directs the Secretary of Defense, in coordination with a number of other agencies across the government, to develop an analysis of the security implications of climate change, a "Climate Risk Analysis," that can be incorporated into modeling, simulation, war-gaming, and other analyses; and
  • Directs the Secretary of Homeland Security to consider the implications of climate change in the Arctic and along our Nation's borders.

Finally, the third EO, signed on February 4, 2021, addresses the international security implications of climate related migration. The EO directs the Assistant to the President for National Security Affairs, in consultation with various agency secretaries, to prepare a report addressing:

  • The international security implications of climate-related migration;
  • Options for protection and resettlement of individuals displaced directly or indirectly from climate change;
  • Proposals for how these findings should affect use of US foreign assistance to mitigate the negative impacts of climate change; and
  • Opportunities to work collaboratively with other countries, international organizations, and localities to respond to migration resulting directly or indirectly from climate change.


Climate change threatens our national security; yet, in recent decades the connection between climate change and national security has rarely been identified in the National Security Strategy. Bush acknowledged the importance of climate change, but not as a security threat. Trump sanitized climate change from the NSS. Comparatively, Obama recognized the threat posed by climate change, and the Paris Climate Agreement was a monumental step in attempting to mitigate the threat. Given the Biden administration's early emphasis on climate security, it is expected that it will be a central feature of his first NSS. Early indications are that climate change finally will get the whole-of-government and national security attention it deserves.


Copyright © 2021 by the American Security Project. This is an edited version of a report originally published on March 2, 2021. Reprinted here with permission.