Global | Militaries feeling the heat as temperatures rise

Military wherewithal to train, fight and win is being tested globally by more frequent and extreme climate events, including floods and wildfires 

• Climate risks place new demands on armed forces and undermine their operational effectiveness, weakening some states’ ability to provide security
• China and Russia will probably seek to pursue their interests more assertively if they perceive the US and its allies are more focused on responding to climate risks

Major Western powers will probably dedicate more resources towards defence this decade. That is while their militaries become entangled in responding to domestic climate disasters. Otherwise they will potentially have to make hard choices between contributing towards resilience at home and responding to threats abroad. These include challenges emanating from Russia, instability in the Middle East and great power competition in the Indo-Pacific.

Western international security alliances like NATO have the potential to become strained too. This is as members have less bandwidth to engage in them, and while the likelihood of violent conflict in fragile states increases. China and Russia, are likely to become more assertive if they perceive that the US and its allies are diverting more resources towards dealing with climate shocks. This would most likely include efforts by Moscow to expand its influence in Africa, where some Western militaries are de-prioritising engagement.

Climate extremes are placing demands on militaries

Extreme climate events are becoming more frequent, severe and disruptive. Temperatures were the highest on record in January for the eighth month in a row. And drier-than-usual conditions were recorded in parts of Asia, the Arabian Peninsula, the Horn of Africa and South America. In Chile, where wildfires became more lethal due to hotter temperatures, the authorities declared a state of emergency on 3 February. This follows unprecedented flooding last year – including in Libya, China and the US – and record-breaking fires in Canada and Europe.

For most militaries worldwide, responding to climate hazards is not a new task. This is particularly in countries where fire fighting and other civil protection agencies are weak. But the frequency with which many armed forces are called on to deliver these responses is likely to accelerate in the long term as global temperatures soar. Recent data from the US-based Center for Climate and Security – which monitors military responses to extreme weather events – shows that militaries responded to climate hazards in more than a quarter of states globally in 2023. More than 130 such events were recorded in the final six months of the year, compared with 55 during the same period in 2022.

So far this year, at least sixteen such incidents have already been identified. In January and February, for example:

• The Australian army was dispatched to help communities in northern Queensland recover from widespread flooding caused by Cyclone Jasper
• German soldiers helped stabilise sections of a dike in Saxony-Anhalt following intense flooding after extreme rainfall
• The Colombian army deployed more than 600 soldiers to assist in fire-fighting operations in central and northeastern Colombia
• The Pakistan army assisted with disaster relief and rescue operations after heavy rainfall caused severe flooding in Gwadar

We are not aware that any major powers have had to choose between providing military responses to extreme climate events or delivering traditional defence activities. But we anticipate that this is a dilemma which many defence departments will face over the next five years and beyond.

Armed forces within Western countries – particularly within the Euro-Atlantic area – are being relied on more to respond to climate hazards. Of the 176 military responses to climate hazards recorded in 2023, roughly half occurred within a NATO member state. It is plausible that this trend reflects gaps in data collection. But if correct, it would reveal the challenge which climate change poses. Europe is now the fastest-warming continent globally. And a 1.5 degrees temperature rise in the 12 months up to January 2024 has brought extreme heat, precipitation and flooding.

Security forces, within conflict and climate-vulnerable states with fewer defence resources, such as Niger and the Philippines, will probably be less able to conduct military operations as climate extremes become more common. The consequences would include reduced bandwidth for counter-terrorism and countering illegal wildlife trafficking operations that also have a bearing on Western states’ security.

Climate risks are eroding military advantage

Requirements for Western militaries to support disaster response efforts are growing at a time when defence ministries are also being called on to respond to – or at least be readied for – geopolitical risks. And when investment in non-military led disaster relief is under pressure. The war in Ukraine, the Israel-Hamas conflict and competition with China are all driving pressure on Western governments to invest more in defence. For major European powers, the looming prospect of a second Trump presidency also raises questions about rearmament, which would require further defence spending.

Many Western militaries face becoming overstretched in the next few years as mounting climate risks simultaneously place demands on defence budgets. And for some, this will merely compound already low levels of combat readiness. Only 58% of the Canadian Armed Forces would be able to respond to an urgent call from NATO allies in the event of a crisis. This is based on Canadian defence documents leaked in early March. While almost half of the country’s military equipment is considered ‘unavailable or unusable’.
Extremes in weather and temperature have an adverse effect on the operational effectiveness of both equipment and personnel by:

• Rendering training sites less accessible, reducing the ability of military personnel to rehearse
• Causing unplanned operational downtime at air, sea and space ports
• Forcing militaries to invest at critical sites, including for logistics

For Western states, maintaining a highly effective war fighting capability is therefore likely to become even more resource intensive. That is amid trends in reducing budgets, and competing geopolitical and national priorities. At least a few NATO member states, for example, are very likely to prioritise responding to climate insecurity at home over supporting allies. This is in spite of concerns among some member states about the potential for a decades-long confrontation with Russia.

Navigating climate risks demands more defence resources

Defence ministries can probably spread such costs over the long term. But it appears that they will face tough trade-offs. Defence officials will need to make hard choices between which battles can feasibly be fought, allies that can be assisted, and modernisation programmes to prioritise. They will also probably have difficult conversations with electorates about why defence coffers should be bolstered, potentially over other areas of public spending – such as emergency services and other civil first responders (let alone education and social care).

Some states, including China, Russia and North Korea, are likely to view Western militaries’ climate troubles as an opportunity. And they would attempt to test competitors, by pursuing their interests during moments of elevated climate insecurity. These states are not bound by the same requirements or expectations as many of their Western counterparts, despite having to contend with their share of climate stressors. The result is likely to be a volatile and unpredictable geostrategic environment over the coming years for governments and businesses alike.