The Allies are individually responsible for adapting to climate change but the Alliance must also act collectively. It is urgent that NATO comprehensively recognises changes in environmental conditions, responds to climate change and adapts its capabilities. Climate change and extreme weather have significant military implications for NATO on the tactical, operational and military-strategic level.

NATO is the largest military alliance in the world. Its multinational character, and the constant adaptation of its structure and capabilities, allow it to respond rapidly to a changing security landscape, including environmental change.

The World Economic Forum’s Global Risks Report (pdf) ranks ’Extreme Weather’ as number one of the top ten risks in terms of likelihood. ‘Climate Action Failure’ ranks number one in terms of impact – ahead of ‘weapons of mass destruction’, ‘cyber attacks’, and ‘infectious diseases’. Extreme weather and climate action failure are therefore the determining characteristics in this risk matrix, ranking well before the economic, societal and technological categories.

According to the report, climate change “is striking harder and more rapidly than many expected. The last five years are on track to be the warmest on record, natural disasters are becoming more intense and more frequent, and last year witnessed unprecedented extreme weather throughout the world.”

Behind the science

Measurements of the anthropogenic (i.e. man-made) increase in the concentration of greenhouse gases (GHG) over the past 200 years indicate significant global warming of the components of the climate system (atmosphere, oceans, land and ice masses) over several decades. Circulation patterns in the Ocean-Atmosphere System are constantly changing, resulting in fluctuations on different time scales. The long-term trend towards global warming as well as its rapid speed demonstrate that the current changes differ from previous natural variations.

For NATO, this means that the future environment in which it will operate will change dramatically. If the Alliance wants to remain an effective security provider, it needs to understand the implications of climate change, and adapt its strategies and capabilities accordingly.

A general orientation that can serve as a basis for NATO’s adaptation efforts is the work of the Intergovernmental Panel on Climate Change (IPCC). The IPCC is the United Nations’ body for assessing the science related to climate change and features 195 member countries plus 161 observer organisations.

All NATO countries are IPCC members. The IPCC’s scenarios, based on a Representative Concentration Pathway, demonstrate a solid scientific and national consensus and thus should generally guide political action. NATO needs comprehensively to assess this consensus, which also includes extreme scenarios and the high dynamics of climatic change processes, with all their risks.

For the two Representative Concentration Pathway (RCP) scenarios – RCP 2.6 (very stringent pathway) and RCP8.5 (worst case scenario) – the mean surface temperature change, as compared to 1986-2005, shows similar heating patterns. The strongest temperature change is forecast for the Arctic with an increase of more than 10 degrees (RCP1.9 is a pathway that limits global warming limit below 1.5 °C, the aspirational goal of the Paris Agreement). Source: DKRZ/MPI-M

From the perspective of risk management, environmental security, and the maintenance of defence capabilities, various aspects must be considered:

  • According to new scientific evaluations, mounting evidence shows that what once was considered the IPCC’s "worst case scenario"(surging GHG and a rise of temperature up to 5C above pre industrial times by 2100) will become the accepted baseline. It should therefore serve as an action option for capability adjustments and guide military strategic planning.

  • GHG concentrations will not fall abruptly, despite all political efforts.

  • The Arctic is the hotspot of climate change.

  • The thawing of permafrost releases methane, which is significantly more potent than carbon dioxide. This means that various complex processes (i.e. biotic feedbacks), which may also contribute to global warming, are not yet included in the IPCC climate models. In other words, one has to assume that the problem will get even worse.

  • Regional shifts of ocean currents and change of thermoclines (large-scale density-driven circulation in the ocean, caused by differences in temperature and salinity) are occurring.

  • Climate models have for a long time correctly predicted the cooling of the subpolar Atlantic, which is apparently associated with a weakening of the Gulf Stream system.

  • The risk of tipping points – a threshold that can lead to a critical irreversible new state of the Atmosphere-Ocean system – must be observed and constantly evaluated as to consequences for military operations.

  • It is important to base operational military planning on the impact of the most likely IPCC scenario – especially as some NATO operations may last more than a decade.

All the climate scenarios discussed will have consequences for the military. From an operational perspective, the challenges for the armed services are as follows:

Air operations

Changes in climate will impact air operations in several ways. Aircraft performance during take-offs and landings is directly dependent on air temperature, pressure (or airfield altitude) and wind. Rising temperatures due to climate change degrade an aircraft’s performance and may require runway extensions or engine updates. Such was the case with transport planes and helicopters in Afghanistan.

The higher frequency and intensity of sand and dust storms, which are caused by the rise of arid and semi-arid sub-regions, will increasingly impede operations due to visual flight restrictions (in operational areas, flights are tactical and therefore usually based on Visual Flight Range rules).

Sand and dust storm approaches Mazar-e Sharif ISAF camp in Afghanistan with upcoming deterioration of visibility < 100 m. In the case of no visual flight conditions, the tactical options, including rescue operations, are severely limited. Human health is also affected (increasing the risk of infection) and there is interference with emerging solar installations. Source: German Armed Forces

The stronger North Atlantic jet stream resulting from climate change will increase the risk of stronger wind shear and clear air turbulence. Since planes – in particular cargo planes – should avoid areas with strong turbulence, mission planning is further impaired. A regional shift in the jet stream will directly impact air traffic in the busy transatlantic air corridor. Moreover, one must also consider the harmful cosmic radiation exposure of crews on northern routes and missions.

Another challenge for air operations caused by climate change is the overheating of military aircraft and airbase installations – an increased logistical effort and higher energy consumption is required to compensate for this.

Changes in the main wind directions of airports (gradual exceeding of the maximum crosswind component of aircraft) must also be taken into account and may require structural modifications, such as changing the direction of runways.

In the Artic/High North Region, changes in climate will generate a need to modify de-icing requirements (with increased environmental protection), supply routes (potentially impeded by thawing permafrost) and airfields (e.g. availability of alternative sustainable fuels). Search and Rescue procedures will also have to be adapted. Future missions by Unmanned Aerial Vehicles will require stable data links for communication and resilient GPS systems for control and application procedures. Both are subject to severe disturbances in the Arctic as well as to space weather effects, and may require additional investments to make them more resilient.

Maritime operations

NATO's maritime capabilities in the Arctic will face a number of challenges. This is due to the combination of extremely cold air temperatures with high wind speeds, ice obstacles, high sea states or waves, remoteness (e.g. GPS failures/inaccuracies due to space weather effects coupled with high navigation demand) and increased radiation exposure due to the depletion of the ozone layer above the Arctic. Weapon systems and ammunition must be adapted to the extreme temperature conditions and rapid temperature changes (weapon systems and sensors are mostly optimised for specific temperature ranges) ) – such adaptation requirements can be anticipated, if necessary, via simulation.

In warmer waters, the situation is equally dire. For example, increased salinity in the Gulf of Aden has caused turbines on several UK frigates to fail. Instability due to drought, desertification and famine has led to an increase in piracy – a good example of how indirect consequences of climate change can affect NATO operations. The oceanographic processes (i.e. cooling of the subpolar Atlantic) are associated with changes in precipitation patterns and additional drivers of the rise of sea levels. Changes in maritime flow patterns will also have implications for Maritime Reconnaissance and Surveillance and submarine warfare.

Climate change also affects the maritime economy. The retreat of ice in the Arctic will open up new trade routes and spark a competition for resources. The vast geographic expanse and sparse coastlines are likely to create additional tensions regarding the exploitation of new maritime resources and raw materials. However, it should be noted that the possibilities for exploration on land and in the air are limited due to the nature of the environment.

Land operations

We can expect equally severe impacts on land operations. Operating in increasingly extreme climatic conditions will present challenges for military personnel, for example, reducing the supply of drinking water due to desertification in certain regions. A recent Pentagon report has found that more than 50 per cent of US military bases, including operational bases abroad, are at grave risk from flooding, extreme temperatures, wind, drought and wildfire.

Extreme climatic conditions also cause faster ‘wear and tear’ of equipment (weapons, vehicles, etc.). For example, the arid environment in Afghanistan caused weapons to ‘jam’ more often. And military bases struggled with the need for cooling, since the heat affected soldiers (increasing physiological heat stress) as well as computers and other electronic equipment.

Climate change also poses significant challenges to military logistics. For example, flooding, snow/ice or storms could block operational supply routes. Transport routes that rely on coastal roads are particularly vulnerable to weather extremes.

Space operations

The space domain is not immune to climate change either. Launch facilities are typically close to shorelines and marginally above sea level, putting them at risk from sea-level rise associated with climate change. Unpredictable wind gusts and alterations to wind patterns could influence launch trajectories for satellites and missiles, challenging the viability of space operations in certain regions.

Changes in the upper atmospheric layers and the need to make the satellites resistant to space weather effects will pose challenges for the planning of new space mission launch centres, operations and applications, which include earth observation, optical links, broad band data transmission, border and pipeline-monitoring, and flood disaster management. This is all the more serious given the fact that, in the next few years, hundreds of pico- (mass up to 1kg), micro- ( ≤ 100 kg) or small satellites (≤ 500 kg) are expected to be launched for civil and military applications.

The way ahead

Given the severe impediments that climate change causes for military operations, a NATO response is overdue.

Among many things, Allies need to measure and provide standardised environmental data to improve predictability and climate modelling. The Alliance could also act as a driver of technological innovation in sustainable and GHG-neutral propulsion systems in aviation and in the maritime domain. Artificial Intelligence and new Earth observation systems offer new approaches to analyse climate change and its impact.

Given the risk of positive feedbacks, the risk of tipping points, further global warming in the coming decades combined with long-term and irreversible shifts in weather patterns, a radically new situation is emerging for NATO’s militaries. Nevertheless, the Alliance can adapt in many ways.

On 23-24 March 2021, NATO Foreign Ministers approved a specific agenda on climate change and security. An action plan will follow to lay out what NATO will do to increase awareness by monitoring and tracking climate change, to operate to the new environment and to mitigate the effects of climate change.

This is the first in a mini-series on the operational implications of climate change. An upcoming article will consider space weather effects and climate change-induced changes in the upper atmosphere, which pose further threats to environmental and energy security.