Lake Powell.

Arizona’s Lake Powell, the second biggest reservoir in the United States, dropped to record low water levels when drought hit the region this past summer.

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Nation & World

How climate change will impact national security

8 min read

Belfer Center research director examines recent assessment from entire U.S. intelligence community

Rising temperatures and intensifying weather due to climate change, along with the unlikelihood of meeting the 2030 emissions goals of the Paris Agreement, will exacerbate geopolitical tensions, social instability, and the need for humanitarian aid, according to a joint report by the U.S intelligence community last month. The National Intelligence Estimate lays out the likely security implications over the next two decades of the mounting climate crisis. Calder Walton is assistant director for research at the Belfer Center’s Intelligence Project, which organized Harvard Kennedy School’s first conference on climate change and national security last spring. He spoke to the Gazette about the report and the important role the intelligence community should play in addressing the crisis. Interview is edited for clarity and length.


Calder Walton

GAZETTE: We hear about the threats posed by climate change from an environmental standpoint, but rarely about the risks and threats it poses to national security. How does the U.S. intelligence community view climate change, and is this a new domain?

WALTON: The purpose of the U.S. intelligence community, established after the Second World War in the wake of Pearl Harbor, was to provide policymakers with decision advantage and forewarning of threats to national security. If the primary purpose is to give decision advantages about national security threats, obviously, by definition, the U.S. intelligence community has to have a role giving key decision-makers their assessments about the greatest existential threat in human civilization: climate change. What is going to be the impact of changing climate on national security, economic society, civil society? And this isn’t just national security; this is international, globalized security. If we look at it like that, clearly, the U.S. intelligence community has to have a role. And they’re very, very late to the game.

GAZETTE: How are other intelligence services responding to climate change? Is any country leading the way?

WALTON: I don’t think anyone is a shining star in terms of taking this seriously. I have yet to find an example of a country that has an intelligence bureaucracy set up to really deal with this and to provide assessments about the national security implications of climate change to policy leaders in a sufficient way.

The overwhelming focus of intelligence communities across the globe is still on post-Cold War structures — stealing other people’s secrets. And we are now in an age of globalized challenges, the primary one being climate change, but also the bio revolution and biosecurity, cyber, and disinformation. Climate change and pandemics are linked; climate change will, scientists tell us, create more new disease outbreaks. And then, add in synthesized biology; we have cyber, artificial intelligence, and machine learning. These are globalized challenges that will affect societies across the world.

We are really at an inflection point in terms of the way that we understand intelligence and national security. U.S. national security and intelligence were built up to deal with blocs of states, first the fascist states and then Soviet communism. Nine-eleven was the first wake-up call about non-state actors, but the U.S. intelligence community still used the same framework of established bureaucracies built up in postwar years to deal with non-state actors. And now, with a pandemic and climate change, we’re seeing truly globalized challenges. It seems to me that we need to rethink how we understand intelligence to deal with it, geared to sharing global intelligence to deal with global challenges we face.

“Scarce resources leading to political violence, terrorism — that’s the kind of secondary threat progression that the U.S. intelligence community will be looking at.”

Calder Walton

GAZETTE: What are the most important takeaways from this report?

WALTON: Let’s start with the basics: that climate change does pose a threat to U.S. national security. The National Intelligence Estimate is a joint assessment produced by the entire U.S. intelligence community, 18 agencies. That’s significant. There are no naysayers; there’s no doubt. So that’s a breakthrough. In this extraordinarily polarized and politicized environment, that is a big milestone itself.

There is a series of direct and indirect security threats that the report lays out. First and foremost, it says that it is likely that the temperature will rise by 1.5 degrees by 2030, which is the Paris Agreement target. So, we are unlikely to stop that from happening. And then, the report reveals the direct and indirect consequences of climate change: raising temperature and the inability of, as they see it, our decarbonization efforts to prevent that temperature rise in the U.S. Direct consequences relate to territorial integrity. The U.S. military’s been talking about rising sea levels on bases since the 1970s, if not earlier. Rising sea level, which is affecting how we’re undertaking military operations. And then, the secondary knock-on effects of population displacement, of civil disorder as key essentials become scarce, damage to crops, and economic realignment. Also, refugee crises or population displacement, and radicalization of people angry with their own government or willing to take action against countries that they regard as the big polluters. Scarce resources leading to political violence, terrorism — that’s the kind of secondary threat progression that the U.S. intelligence community will be looking at.

GAZETTE: China accounts for 30 percent of the world’s carbon emissions, followed by the U.S. Are the risks from climate change multiplying the existing concerns U.S. intelligence has about China, and does it change their approach?

WALTON: It is. What we’re witnessing is the combination of these global challenges to international security — biosecurity, natural and synthesized biology and pandemics, climate change, disinformation — being fused with great power, geopolitical conflicts. There’s this idea that we can either deal with the international security threats of climate change or China. But in reality, they are not mutually exclusive; they’re all interwoven. Climate change is now fused with geopolitics.

How is the U.S. intelligence community thinking about China and these issues? This is an area firmly within the traditional wheelhouse of what the U.S. intelligence community can do. The absolutely important information will be verification and attribution: whether China is adhering to its public statements about its carbon reduction. Is it being truthful or is it not being truthful? That’s where intelligence collection — human intelligence, signals intelligence, imagery intelligence from satellite, overhead reconnaissance, and open-source intelligence — is going to be absolutely key. Senior policymakers in Washington will say, “I need to know whether China is adhering to what they profess to be doing in terms of decarbonization.” So that will be a requirement set to the U.S. Intelligence Committee, to steal those secrets. That is not that different from what we’ve done in the past, and will be increasingly important.

There is a significant role the U.S. intelligence community could play and really, in my view, must play going forward. It’s disseminating its assessments, particularly from overhead satellite mapping, what the U.S. intelligence community is observing both on the territorial integrity of countries and population displacement. During the Ebola crisis, the U.S. National Geospatial Intelligence agency, through its satellite platforms, collected and then publicly disseminated via its website information about the spread of Ebola in West Africa. That is exactly the direction that we need to go in with climate change.

GAZETTE: What comes after this report? Is there a next step?

WALTON: The next step is for the U.S. intelligence community to say, “This is what we can deliver. We know what we need; we know what policymakers need to know; we know what the public needs to know; and this is how we can contribute to assessments and messaging and help shape public policy.” The worst thing they could do would be to set up a new bureaucracy within a particular agency and say, “We’re now doing climate change.” It’s time for some bold thinking. This is a profound existential crisis for the way we live our lives, and it’s time for profound thinking about intelligence to inform decision-making. Instead of the traditional focus of intelligence agencies to retain information because it is classified, it seems to me that when it comes to climate change the emphasis should be about publicly disseminating that intelligence. In other words, a reversal of tradition.

It’s incumbent for assessments to be as widely read as possible so that we understand this, so that members of the public can hold policymakers’ feet to the coals about making changes. There’s no good if we find out in 50 years’ time, they were being briefed on this. The stakes are too high for that.