In warfare, “scorched earth” can have a number of meanings. In the larger scope of military operations, there is particular concern about the effect conflict can have on the environment and the spaces people live in, which can suffer severe damage as a result.
Military activity can pollute water tables and tear up land. The effects last decades, including toxicity from chemicals, gas and other pollutants that can get into the ground. These environmental factors add to challenges of food security and supply.
Environmental damage is an inescapable consequence of combat operations anywhere they occur. According to historical research, even in ancient times the massing of armies “destroyed the harvest and turned the battlefield to mud.” Nowadays, the destructive power of weaponry and modern warfare techniques has dramatically increased the environmental effects of military operations.
Effects on the environment are increased by population growth, the intensive extraction and use of natural resources, and the systemic destruction and fragmentation of habitats as a result of urbanization, agriculture, mechanized land clearing and transportation systems.
Dozens of ongoing conflicts around the world are causing damage to ecosystems. Some forces, if trained correctly, understand how environmental considerations affect military planning. For a commander tasked with defeating an enemy force and seizing its defensive position, for example, understanding where enemy fuel storage facilities are located is important. They might be located close to water sources that supply a significant portion of the local population.
High-intensity conflicts require and consume vast quantities of fuel, leading to high levels of carbon dioxide emissions, contributing to climate change. Smoke from fires also has damaging effects on the environment and on civilians stuck between warring forces.
Large-scale vehicle movements can cause widespread physical damage to sensitive landscapes and geodiversity, as can the intensive use of explosive ordnance. The use of explosive weapons in urban areas creates vast quantities of debris and rubble, which can cause air and soil pollution. Pollution can also be caused by damage to light industry and other environmentally sensitive infrastructure, such as water treatment plants.
The loss of energy supplies can have reverberating effects that are detrimental to the environment, for example by forcing treatment plants or pumping systems to shut down, or can result in the use of more polluting fuels or domestic generators.
There are other environmental considerations related to conflicts. Military forces need large areas of land and sea in which to operate, whether for bases and facilities or for testing and training. Between 1 percent and 6 percent of land globally is believed to be used by the military. In many cases, this land is in ecologically important areas. While protecting environmentally sensitive areas from development can benefit biodiversity, the question of whether they could be better managed as protected areas is rarely discussed. Military training creates emissions and disruption to habitats on land and at sea, as well as chemical and noise pollution from the use of weapons, aircraft and vehicles.
Maintaining and renewing military equipment and materials also results in ongoing disposal costs, with resultant implications for the environment. It is not only the most hazardous arms, such as nuclear and chemical weapons, that create environmental problems. Conventional weapons also cause problems, particularly where they are disposed of through open burning or detonation. Historically, vast quantities of surplus munitions are dumped at sea — a practice that must be banned completely.
Another aspect of the problem is weak oversight of the environmental damage caused by military forces. This lack of regulation leaves many countries facing serious environmental legacies linked to military pollution that affect public health and cost huge amounts to remedy. The challenges continue to grow as new pollutants, such as “forever chemicals” that take a very long time to break down, are identified.
The environmental legacies of military activity are also a problem in the areas around overseas bases, where one-sided agreements with host nations can reduce environmental oversight. The formation of bilateral military relationships should therefore include environmental components and consideration of the effects on climate change. The military is simply not ready for the climatic changes predicted to occur by 2030.
Conflicts and other activities involving the military or armed groups are polluters that require oversight, regulation and penalties for transgressions when possible. Damage to the environment during an uprising, insurrection, terrorist attack or combat, especially when infrastructure is targeted, has a lasting effect on populations and their security.
Some armed conflicts can be brief but highly destructive. Some civil wars last for decades but are low intensity. Many contemporary conflicts blur those lines, lasting for years but with sustained bursts of high-intensity warfare. Who is fighting, where they are fighting and how they are fighting all strongly influence the environmental effects of their disputes.