War is Bad for Planet Earth

by Gail Payne, Nuclear Issues Chair

War’s human cost is usually the first thing we think about, and rightly so. But war also has a serious environmental cost that rarely receives adequate attention. Around the world, armed conflict and military activity can damage air, water, soil, farmland, wildlife habitat, coastal areas, and the infrastructure people depend on for survival. 

Like all wars, the current Mideast war harms the planet War’s impact on the environment rarely makes the news, even though the world spends more on war every year. According to the Stockholm International Peace Research Institute, in 2024 an estimated $2.7 trillion was spent, and of that amount the U.S. contributed $997 billion. This fortune could end global hunger for a decade, or make renewable energy universal.     

Who pays the environmental price?In war, while weapons makers and military contractors make hundreds of billions of dollars, civilians and ecosystems often suffer long after the fighting stops. Recent conflicts in places such as Ukraine, Sudan, Gaza, Lebanon, and elsewhere end up with damaged homes, hospitals, power grids, water systems, farmland, coastlines, and sanitation systems. Fires, toxic debris, unexploded ordnance, fuel contamination, and damaged wastewater systems can pollute ecosystems and undermine resources that communities need, including fisheries, farmland, drinking water, and energy supplies.     

One example according to Greenpeace Germany, a single oil spill in the Persian Gulf could damage this fragile marine habitat. Research in Sudan shows that war drives deforestation, agricultural decline and industrial pollution, undermining people’s access to food, water and energy.      

Environmental harm from war is not limited to one region or one side. It is a global problem. Wherever war occurs, the damage can spread across borders through air pollution, water contamination, food insecurity, refugee displacement, and climate impacts.                

How does war accelerate climate change?At minimum, researchers estimate that militaries account for around 5.5% of global greenhouse gas emissions, although the true number is difficult to measure because military emissions are not consistently reported. War itself adds further emissions through explosions, fires, reconstruction needs, destroyed infrastructure, and disrupted energy systems. The war on Gaza generated an estimated half-million tons of carbon dioxide in the first 120 days.

What is the toxic legacy of war?History is full of long-lasting environmental horrors delivered by wars, from the “scorched earth policy” of the Scythians to modern times. The environmental damage of war does not end with a ceasefire. During the Vietnam war, US forces sprayed over 21 million gallons of herbicides, including Agent Orange, contaminating 7.2 million acres of land, water and food chains with dioxin. In Iraq, depleted uranium and other toxic remnants of the Second Gulf War harmed the environment and human health. Several groups are demanding that the Israeli Government be investigated for the Rome Statute war crime of ecocide for “widespread, long-term and severe damage to the natural environment.”

What is the role of fossil fuels during war?Oil and gas both fuel war and intensify war’s environmental impact. Recent wars are driven by our dependence on oil and gas and the need to control pipelines, ports, tankers and shipping chokepoints. When the global economy depends on centralized, combustible resources, attacks on fossil fuel infrastructure do more than disrupt trade. They damage marine ecosystems, public health, air quality and temperature, and affect economic stability at the same time. The invasion of Venezuela was arguably to control Venezuela’s massive oil resources.      

How do renewables support peace & planet?Renewables are not a geographically-based resource to be fought over. Sunlight cannot get stuck in the Strait of Hormuz; wind can’t be wiped out by weapons of war. A decentralized network of rooftop solar, batteries, local grids and efficiency are harder to bomb than oil fields and pipelines, and can help keep homes, schools and hospitals functioning during wartime. Renewables don’t inflict fuel price shocks. Local renewables cannot stop a war, but they can reduce the power of fossil fuel cartels, keep essential services running and reduce the environmental damage that comes from defending centralized, combustible infrastructure.

What can we do to stop this vicious cycle?  • Advocate for Diplomacy ove rmilitary“solutions”: Participate in public demonstrations, protests and pressure campaigns.• Strengthen Legal Norms: Hold leaders accountable for war crimes and destruction of the environment.• Highlight Environmental Destruction: Point out that war consumes resources and pollutes air, water and ecosystems.• Teach Peace: Replace education that glorifies conflict with curricula focused on conflict resolution, tolerance, and the human and environmental costs of war.

For environmentalists, war’s impact is not a side issue. Protecting the planet means recognizing all major sources of pollution and climate disruption, including those connected to war, military preparation, and postwar rebuilding.

A conservation message

The Sierra Club’s mission is to protect the natural world and the communities that depend on it. That mission includes calling attention to the environmental consequences of war and encouraging policies that reduce conflict, protect civilians, safeguard ecosystems, and redirect resources toward a livable future. War harms people first. But it also harms the land, water, air, climate, and living systems on which people depend. That environmental cost deserves to be part of the public conversation.