Riot police officers clash with protesters during the eviction of about 300 people who were blocking the entrance of a mining company outside of Guatemala City on May 23, 2014. (Photo: Johan Ordonez/AFP/Getty Images)

On a January morning, I was crammed in the backseat of a bus as it climbed into the mountains outside Mataquescuintla, a small city in Guatemala’s agrarian heartland. As we bounced along a rutted road, one of my traveling companions, an international human rights activist, pointed out a window at the street corner where the shooting took place.

There, on April 13, 2014, unknown assailants gunned down Alex Reynoso and his daughter, Marilyn Topacio, both prominent environmentalists in the region. Marilyn, who at 16 years old was already a respected organizer, died of her wounds. Alex spent more than a month in a local hospital, and survived.

Reynoso and his family are leaders in a peaceful resistance movement that opposes the nearby Escobal silver mine, a massive operation owned by the Canadian firm Tahoe Resources, Inc. Escobal has been pulling metals from the Guatemalan ground since 2013, despite dogged protests and lawsuits from some locals who see it as a foreign intrusion and a potential source of pollution.

“Environmentalists are being killed at the rate of two a week for defending their land and the problem is not well-reported. It needs to be addressed.”

A few miles further, amid banana trees and thick brush, we passed the site of the second assassination attempt. Here, on October 17, 2015, men on a motorcycle ambushed Reynoso as he drove home at dusk. The attackers came out of the forest and opened fire. Reynoso took bullets in his back, and survived.

No one has been held accountable for the attacks and Tahoe denies any connection to the crime, but Reynoso believes the men who want him dead are local mine supporters. His contention is rooted in context: Mine opponents have faced persistent repression. In April 2013, for instance, seven peaceful protesters were shot and wounded by security at the mine’s gates. Others in the resistance have been jailed or killed. The Reynoso family’s story is part of this violent pattern. The violence, though, is not confined to one mine. Attacks on leaders like Alex, whether in Guatemala or Congo or Cambodia, are not an aberration.

Every year, across the globe, environmentalists opposed to mining, oil extraction, and timber production are killed in great numbers. The frequency of such assassinations is downright disturbing: In 2014, at least 116 environmental activists were murdered worldwide, according to a report released last April by Global Witness, an anti-corruption group in the United Kingdom. Between December 2009 and December 2015, to take a longer view, the total tally of such killings came in at 640.

“A shocking 40% of the victims were indigenous,” Global Witness wrote in its April report, “with most people dying amid disputes over hydropower, mining and agri-business.” The murders occur most often in Latin America, Asia, and Africa, where multinational corporations and local businesses alike can pursue profit with little legal oversight. In general, the killings take place amid contentious land disputes that pit neighbor against neighbor. In general, the killers are not held accountable.

Consider the case of Emirito Samarca, Dionel Campos, and Bello Sinzo, indigenous Filipinos opposed to mining on their people's traditional lands. All three were murdered on the same day last September, allegedly by members of a local paramilitary group. Consider the killing of Edwin Chota, a prominent indigenous anti-logging campaigner in Peru who was gunned down in September 2014 along with three of his allies. Consider the death of Chai Bunthonglek, a high-profile activist who led campaigns against palm oil companies in Thailand. According to Global Witness, unidentified gunmen murdered him in his home last February. With the exception of the Chota case, the perpetrators killed with impunity.

A man bleeds after being injured during the clashes between protesters and the riot police outside of the entrance to a mining company. (Photo: Johan Ordonez/AFP/Getty Images)

The Reynoso family’s tragedy, in this context, is just one more disturbing consequence of the mad scramble for minerals, timber, oil, and other natural resources on our picked-over planet.

“Rapacious corporate interests are riding roughshod over environmental and land activists in order to access natural resources,” says Billy Kyte, a campaigner with Global Witness. “Environmentalists are being killed at the rate of two a week for defending their land and the problem is not well-reported. It needs to be addressed.”

As the famous Earth Day flag suggests, the environmental movement has long had global ambitions. But how does the movement hope to prevail in its campaigns against deforestation, illegal mining, climate change, and the like? How can conservation possibly succeed on a planetary scale if key green leaders and allies keep getting gunned down?

“There has been more than one occasion where we have been collaborating with someone in the field and then they end up murdered,” says Daniel Brindis, Greenpeace’s senior forest campaigner. “Based on our experience in Brazil, it is a very common problem.”

The problem seems insurmountable, but there are solutions. It’s instructive to look at how journalists, another oft-threatened group, deal with such perils. Global Witness points out that, in 2014, the number of environmentalists murdered was double that of journalists murdered. Yet journalists have rallied to combat their killers. In the Committee to Protect Journalists, reporters worldwide have a prominent organization solely focused on defending them against repression and violence. Among other things, CPJ, with backing from prominent media groups, tracks the killing and jailing of journalists, leads campaigns to bring perpetrators to justice, travels to countries where the press faces reprisals, and advocates in international bodies. CPJ’s work puts killers in jail and gets journalists out.

Global Witness is doing similarly crucial work, but it can’t be expected to go it alone. The broader environmental movement should rally to the cause. A coalition of powerful green groups, supporting a centralized and well-funded effort to counter environmental killings, would do a great deal to stanch the hemorrhage of international environmental leadership, of human life. Organizations like the Sierra Club, 350.org, Greenpeace, the Natural Resources Defense Council, and others could pool their resources to track murders, advocate on behalf of imperiled environmentalists, and bring this issue to international prominence. And Global Witness, Kyte says, is looking for such allies.

“I do think we need to do it,” says Payal Parekh, 350.org’s global managing director. “We need to work together better and in a more coordinated manner, so that they do not think they can pick us off one by one.”

After the long bus ride, we finally arrived at the home of Alex Reynoso. He lives on a mountainous parcel where coffee plants and banana trees thrive. Though the Escobal mine has turned him into an activist, Alex is a farmer at heart. His land is peaceful and set back from the road, the perfect place to heal. When I met him, he still needed surgery to fix his battered body.

“While I recuperate, I’ve decided to completely detach myself from the resistance movement,” Reynoso says. “I am not going to meetings, not doing anything, until I'm better.”

The attacks took a grave toll on Reynoso. For now, he is out of the fight. Unlike many fellow environmentalists, however, he survives.