For Yeb Saño, the effects of climate change became tragically clearer on Nov. 8, 2013, when Super Typhoon Haiyan made landfall in Southeast Asia. The tropical cyclone—one of the strongest in recorded history—left a massive trail of destruction, particularly in the Philippines, where it claimed thousands of lives.

At the time of the disaster, Saño’s brother, AG, an environmental and peace activist, was in the family’s hometown of Tacloban and helped gather bodies of the deceased in the aftermath.

“He counted at least 73 dead bodies carried by his own hands. We lost friends, loved ones,” Saño said.

Just a few days later, the tragedy led Saño—then chief climate negotiator for the Philippines in the United Nations Framework Convention on Climate Change—to speak on behalf of the lives lost at the hands of Super Typhoon Haiyan at the UN Climate Change Summit in Warsaw, Poland. His heart-wrenching address called for action and was met with a standing ovation. He also fasted for 14 days in solidarity with the victims and all people confronting the impacts of climate change.

“What is heartbreaking is that the people who suffer the most are the ones who contribute the least to the root of the problem: The poor, marginalized and vulnerable groups bearing the brunt of the impacts from the climate emergency contribute the least to the world’s carbon emissions,” he said. “Climate change is one of the biggest injustices in human history.”

Saño’s advocacy for climate justice as chief negotiator for the Philippines captured global attention. In 2016, he was appointed executive director of Greenpeace Southeast Asia, where he continues to strive for social and environmental justice.

To prevent future devastation, Saño said the world must hold those responsible for climate change truly accountable and make them stop the harms they’re inflicting. But action requires immense economic and political transformation—including a transition of energy, transport, and food systems. That means abandoning fossil fuels, such as oil, coal and gas; developing renewable energy systems that support sustainable economic development; and shifting narratives promoted by the fossil fuel industry and colluding government agencies.

“[Fossil fuel industries] have robbed humanity of decades to act on climate change by creating a smokescreen around the truth and reality of the crisis,” he said. “They have also cunningly shaped the wrong notion that the responsibility for the climate crisis rests on the shoulders of individuals rather than on their own questionable business practices.”

To unravel what Saño called the root causes of the climate crisis—greed, arrogance and apathy—Saño said we must implement the same solutions that make the world a better place, from empowering the marginalized to combating consumerism.

“How then do we fight this battle?” he said. “We stand up against every kind of injustice.”