The destructiveness inherent in war is plain to see in the loss of human life, but the environmental costs are equally important yet too often overlooked.

Throughout history, war has been a catalyst for technological advancement. Innovation is borne out of the desire to gain an advantage over the enemy. From developments in aviation capabilities in the First World War to the creation of the atomic bomb in the Second.

Ever-expanding military technology is increasingly deadly and has an increasing thirst for energy. Given the nature of military activity, it lends itself to fossil fuel use owing to its huge reliance on aviation and shipping.

However, decarbonisation is required in every sector if we are to reach net zero globally by 2050, with the aim of limiting global warming to 1.5C above pre-industrial levels. The focus is often placed on reducing the emissions of transport, agriculture and construction within civil society, but the decarbonisation of the military is rarely discussed. There are many questions to be asked about the carbon footprint of war, which could unfortunately increase in prevalence as this century develops and the likelihood of drought, flooding and food scarcity increases as a direct result of human-caused climate change. Notwithstanding this, there are lessons to be learned from wars gone by on how we can win the fight against climate change.

The impact of war

There is no requirement for countries to report their military emissions under the Paris Agreement, so the quality of data globally is very poor. Best estimates, based on the available data, suggest that the global military’s carbon footprint could account for 5.5% of greenhouse gas emissions worldwide.

The US Department of Defence is the largest institutional consumer of oil in the world, using more than 100 million barrels each year — approximately the same amount consumed annually by Austria.

It’s not only people and the planet who suffer in war; for biodiversity, it’s a killer too.

During the Mozambican Civil War, biodiversity was decimated within Gorongosa National Park as soldiers lived off the land. Gorongosa is an example of conflict leading to a breakdown in environmental governance. This left an ecosystem out of balance for decades after the war came to an end, which would not recover without human intervention — but recover it has, with concerted human effort and investment.

Unfortunately, it is not always possible to replenish the biodiversity caught in the crossfire. During the Second World War, Japanese soldiers hunted the Wake Island Rail out of existence. The loss of any life in war is sad; the loss of an entire species, however, is tragic.

Flora can itself be a strategic target in war. For example, during the Vietnam War, a campaign of herbicidal warfare was pursued by the US, which sprayed Agent Orange from aircraft over forests to deprive the Viet Cong of vegetation cover and food. It is estimated that these herbicides were sprayed over 20% of South Vietnam’s forests and 36% of their mangrove forests.

In more recent times, the destruction of the Nova Kakhovka dam in Russian-occupied Ukraine, likely carried out by Russia, was described as ‘ecocide’ by President Zelenskyy due to the significant amounts of oil, chemicals and fertilisers that were released into the Dnipro River and Black Sea. There are numerous areas of ecological significance on the banks of the Dnipro River that have been damaged by flooding caused by the attack. Most notably, the Black Sea Biosphere Reserve, a UNESCO world heritage site.

What can we learn from war in the fight against climate change?

While it is interesting to look at some specific examples, the notion that war is generally bad for the planet is not particularly groundbreaking. However, there are lessons to be learned from wars gone by that offer some provoking thought experiments on the equitable transition to net zero.

For example, in Britain, just days after the Second World War broke out, petrol rationing began. This was calculated based upon need and the distance each person lived from their place of work and was introduced to prevent pleasure motoring in order to save fuel for the armed forces. Unsurprisingly, this led to an increase in the popularity of bicycles and public transport.

Later on in the war, Roosevelt’s appeal to the American people to voluntarily cut driving in half to save fuel for troops was largely ignored, despite the dissemination of propaganda conveying the message that it is patriotic to save fuel. Voluntary constraint proved ineffective, so in 1942 fuel rationing was introduced in the States too. The move was unsurprisingly unpopular but more effective in achieving the desired outcome. This example provides good evidence that sometimes the stick can be more effective than the carrot in getting the population to conform where it is overwhelmingly in the public interest to do so.

While politicians may have found it easier to apply the ‘stick’ during twentieth-century wartime, the twenty-first century’s climate fight requires similar boldness. One could easily draw parallels between, for example, this approach and the Ultra Low Emission Zone (ULEZ) in London today. The expansion of ULEZ, set to occur at the end of this month, has caused upset in many suburban communities of London, and yet its introduction to central London in 2019 has already cut harmful nitrogen dioxide (NO2) concentrations in half, allowing some four million Londoners to breathe cleaner, healthier air. ULEZ might be unpopular, but it works; soon enough, the ‘war footing’ will be forgotten and clean air in the British capital will become the new norm.

Looking to the future, civil society and the military can provide mutual benefits to one another by decarbonising. Automobile makers are heavily investing in electric vehicle technology; it is easy to imagine the on-the-ground advantages for the military of silent vehicles with significantly reduced thermal footprints. Additionally, there are strong strategic arguments for decreasing military dependence on oil, notably the huge cost savings and reduced vulnerability to price volatility or short supply.

Modern warfare has shown mankind’s ability to make rapid scientific advancements where there is a perceived necessity for doing so. This fighting spirit may come in handy in rolling out renewables, decarbonising industries and developing carbon capture and storage technologies.

Climate change is already causing a surge in global migration, which is perhaps going to be the greatest crisis of this century. The most widely cited figure for the total number of climate migrants by 2050 is 200 million people; however, some estimates are as high as 1 billion. As droughts intensify and temperatures rise, once-hospitable regions might become uninhabitable, and crop failures could trigger widespread food shortages. These conditions carry the potential for unprecedented global political instability. How global politics deals with this remains to be seen, but it looks as though warfare is likely to continue. It is our duty to ensure that where conflicts do arise, they are conducted with an unwavering commitment to environmental responsibility. Failure to do so risks chaining humanity to a cycle of self-destruction.