With NATO recently recognizing climate change as a security challenge and setting new targets to reduce its greenhouse-gas emissions, defense forces are eyeing pathways to decarbonization. General Tom Middendorp, who retired as chief of defense for the Netherlands in 2017, now serves as chair of the International Military Council on Climate and Security and is the author of the book Klimaatgeneraal (Uitgeverij Podium, February 2022)—or “climate general.” In a conversation with McKinsey partner Axel Esqué, Middendorp detailed the types of security risks posed by climate change, discussed strategies for decarbonizing the defense sector, and suggested that sustainability efforts might make military units more operationally efficient.
This interview has been edited for length and clarity.
Axel Esqué: How does the defense industry connect the growing focus on sustainability with its core purpose of addressing security challenges?
Tom Middendorp: At first, the nexus between climate and security might not seem obvious. But US intelligence services have been warning us about the interaction between the two for more than 20 years. And we are starting to see how it is affecting military work.
I chair a global network that includes senior leaders from defense organizations in more than 35 countries. They all feel the impact of climate change in their daily work. In Afghanistan, water shortages led to tensions in populations, which were leveraged by the Taliban. In Somalia, we saw how the increasing number of droughts pushed poor farmers and fishers into piracy. In Mali, we saw herders and nomads forced to join extremist organizations. It’s already happening. And that’s now being recognized, which is good.
The next question is, how can the security community react? At the core of the problem is a growing gap between demand and supply. The world population is doubling in size, so demand is rising. Meanwhile, we are short on the supply of many resources, including water and rare minerals. This gap between demand and supply will become a source of friction in the world. And that will lead to disasters, migration flows, extremism, and internal and external conflicts in regions. It’s not a rosy picture, and I think defense communities need to be prepared and to adapt.
Axel Esqué: What are some examples of the different types of impacts that climate change could have on the global defense landscape?
Tom Middendorp: I think you can separate them into two kinds of impacts. First, there are the direct effects. Military forces need to be able to operate in any climate circumstance, which means that they need to adapt equipment, uniforms, and everything else to a changing climate. They also need to protect vital infrastructure such as harbors, or radar stations in coastal areas, against the influences of climate change. And military forces will need to reduce their own emissions to meet climate targets and become more energy independent, which will affect all the capabilities that a military has.
The second category is indirect effects. Climate is a risk multiplier in all regions of the world, causing migrant flows and political tensions—especially in fragile countries that are not resilient to its impacts. Another indirect effect is the increasing frequency of natural disasters, which often result in the military being called upon as first responders. The final indirect effect is geopolitical change resulting from climate change—a good example of this is the Arctic area that’s now melting away, opening up a completely new geopolitical arena.
Axel Esqué: NATO has committed to an at least 45 percent reduction in its greenhouse-gas emissions by 2030, and to go down to net zero by 2050. Momentum seems to be building. Is this a realistic commitment? Is it enough?
Tom Middendorp: The NATO targets refer to the alliance’s own assets, such as its AWACS [Airborne Warning & Control System] surveillance planes, its drones based in Italy, and its headquarters. I think it’s quite ambitious, but it’s the right decision, and I expect member states to follow. It demonstrates leadership and shows that there is no way back. Whether we like it or not, we have to go through this transition. And we need to speed it up.
Let’s see this as an opportunity, not as a threat. The military has always been early to embrace new technologies and has always been a platform for innovation. GPS, the internet—these came from the military and are now being widely used in the world. Why not embrace the enormous potential that green technologies have and be a platform for innovation there?
Axel Esqué: More near term, what would you say is the single key priority for the next two to three years for defense organizations that are thinking about sustainability?
Tom Middendorp: I think there is no golden solution here. We need to climate-proof our organizations, our policies, and our equipment. On the government level, we can do that with policy making and regulations and by setting requirements for future military equipment. That’s happening right now.
I think there is no golden solution here. We need to climate-proof our organizations, our policies, and our equipment.
On the industry side, I think it’s important to refocus R&D on minimizing the logistical footprints of military units and maximizing their energy independence, without reducing their combat effectiveness. And that’s a challenge. It calls for real innovation. The reward is huge, because the company that develops these kinds of technologies will be first in line for any defense organization.
Axel Esqué: Could sustainability efforts have an effect on operational effectiveness?
Tom Middendorp: If we can make units that are more self-sustaining, they won’t need to rely on the huge logistical supply chains that they use now. Those supply chains are the biggest cost driver of any military mission. They are also the biggest risk factor in any mission—the Achilles’ heel of units. They are often targeted by enemies, requiring us to allocate a lot of forces to protect them. The more we can reduce logistical dependence by using green technologies, the more operational gains we can achieve.
Green technologies can also help us to reduce heat and noise signatures. Vehicles running on batteries make less noise and have less of a heat signature. So there is enormous operational potential there.
Axel Esqué: Currently, we’re seeing geopolitical tensions rising to levels unseen since the Cuban missile crisis in 1962. This has resulted in some efforts to secure resources—including fossil fuels. Do you see this as a short-term detour or a longer-term deviation from the sustainability imperative for the defense industry?
Tom Middendorp: There seems to be a tension. Geopolitical factors cause a short-term push for more conventional energy resources, while climate change triggers a long-term effort toward energy transition. But I see them as interrelated. They even reinforce each other.
One effect of the current geopolitical tension is that countries want to become less vulnerable by becoming less energy dependent on other countries. Accelerating energy transition would help them to achieve that independence. At the same time, we need to be aware that energy transition increases the demand for the rare minerals needed for batteries and solar panels. This can result in new resource scarcities—and a need to secure access to these kinds of resources.
Axel Esqué: The defense industry’s supplier landscape is complex. Do you believe every player in the value chain will embrace the same climate-related targets at the same pace?
Tom Middendorp: I think they will need to, because otherwise they will be out of the game. Defense industries have historically proven that they can be front-runners in any new technology. Let’s prove that again with green technologies.
The landscape is full of unique and protected supply chains. I think the challenge is to open up supply chains to smaller enterprises and start-ups that bring innovations to the table. I would like to challenge manufacturers to be courageous and make that shift, because I’m convinced that’s the only way we can move forward.
Axel Esqué: What do you think are the most pragmatic ways to decarbonize defense forces?
Tom Middendorp: I would say let’s start with the low-hanging fruit, meaning our peacetime equipment and our nonoperational facilities and capabilities. This can be done relatively quickly with existing civil technologies.
A second category would be operational capabilities that use comparatively small energy sources—lighter vehicles, unmanned systems, and base camps. We’ll need to redesign current capabilities and adapt them, but I would say that can be done within the next ten years.
The third category is the hardest part because it’s about heavy capabilities—tanks, naval vessels, and fighter jets—that need very intense energy sources, requiring new energy technologies. For this category, it is crucial that we realign R&D to design next-generation capabilities that use alternative energy sources and alternative combustion systems, making them more self-sustaining. But we can also take steps in the meantime—for instance, mixing biofuels into current fuel systems. In my home turf in the Netherlands, we are conducting trials on the use of drop-in biofuels that have been quite successful.