When we think of war crimes, we typically think of actions like taking hostages, torturing prisoners, or enlisting child soldiers. Now a group of scientists wants to add another item to that list: harming the environment.

An open letter signed by 24 prominent scientists from around the world and published this week in the journal Nature calls for a new Geneva Convention that would hold governments responsible for the environmental damage their militaries inflict in war zones.

“We call on governments to incorporate explicit safeguards for biodiversity,” the letter says. “And the military industry must be held more accountable for the impact of its activities.”

Scientists are voicing these demands now for two reasons. First, the UN’s International Law Commission is holding a weeks-long meeting — from July 8 to August 9 — to explore how it might expand on the 28 principles already in place to keep nature safe during war. This is the perfect time to publicly make the case for adopting a new Geneva Convention as part of that effort.

Second, it’s become increasingly clear that our planet is facing an urgent biodiversity crisis. In May, a major UN report found that 1 million species are now at risk of extinction. It noted that all kinds of species, from plants to birds to mammals, are vanishing at a rate “tens to hundreds of times higher than the average over the last 10 million years.” And that’s because of human activities — including war.

Nations at war are often too busy thinking about the human costs of the conflict to spare much thought for the cost to the natural world. That may be understandable, but it’s a mistake nonetheless, because war is absolutely devastating to the environment. And when nature suffers, we humans tend to suffer in turn.

The Iraq War offers a striking example. Years after the 2003 US military assault on Iraq, scientists began to investigate the resulting environmental pollution — including contamination from depleted uranium — as a possible contributor to the country’s plummeting health conditions. “Increases in cancer, birth defects, and other conditions have been associated with war-related environmental damage and toxins” in Iraq, according to researchers with the Costs of War Project at Brown University.

The researchers add that the destruction of military base garbage in burn pits “exposed soldiers and civilians to dangerous levels of pollutants” and that the military’s vehicles raised so much dust that “service members’ exposures to inhaled toxins from that dust have correlated with respiratory disorders.”

War takes a brutal toll on wildlife

In Africa, the number of large animals like elephants can decline by 90 percent during war, according to a wide-ranging study published last year in Nature. For example, one national park in Mozambique lost 90 percent of its wildlife when that country underwent a 15-year civil war.

Another study published last year focused on the Sahara-Sahel region of North Africa — home to Earth’s largest desert — and found that “there is increasing evidence of an ongoing wildlife massacre resulting from growing instability.” In Libya, more gazelles were illegally killed after the 2011 civil war, and in Mali, the number of elephants killed increased after the country’s 2012 conflict.

There are various reasons why animals die off at higher rates in war zones. In some cases, it’s because more guns spread across a country in wartime, enabling more illegal hunting. Often, it’s because resource-strapped governments don’t have the wherewithal to make conservation a priority. Sometimes it’s because extremists and traffickers rush into previously remote areas in an effort to control them, promoting a human presence in areas where animals used to enjoy free rein. More than one of these reasons can be at play in any given war zone.

Now, the signatories to the Nature letter want international law to protect wildlife, including on nature reserves, and to better control the spread of firearms used to hunt animals.

Calls for a new legal instrument that would hold governments criminally responsible for wartime environmental damage have actually been around for two decades. As the Guardian reports:

Work in this field began in the 1990s after the Iraqi military set fire to more than 600 oil wells during a scorched-earth retreat from Kuwait in 1991, but the idea dates back at least to the Vietnam war, when the US military used Agent Orange to clear millions of hectares of forest with dire consequences for human health and wildlife.

Yet, so far, the number of Geneva Conventions has remained static at four (they aim to protect wounded and sick armed forces in the field; wounded, sick, and shipwrecked armed forces at sea; prisoners of war; and civilians). Calls for the addition of a fifth Convention to protect the environment have gone unheeded.

Will that finally change once the International Law Commission meeting wraps up next month? It’s possible, especially as the notion that nature deserves its own legal rights has been gaining ground in recent years. Sarah Durant from the Zoological Society of London, who signed onto the letter in Nature, sounded an optimistic note in an interview with the Guardian.

“We hope governments around the world will enshrine these protections into international law,” she said. “This would not only help safeguard threatened species, but would also support rural communities, both during and post-conflict, whose livelihoods are long-term casualties of environmental destruction.”

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