Before I came to Yale, my family moved. Two years later, I still haven’t unpacked. Boxes and books have accumulated over the years, and I have no idea where to find anything, let alone enough space to move around. The obvious solution would be to unpack and clean my room. But whenever I try to start, I feel completely and totally overwhelmed. I have no idea where to begin.

I feel the same way about climate change, but worse. You can tackle a dirty room with an organizational scheme, some determination and a rainy afternoon. I wish I could think of such a simple solution to the harms caused by the extraction and burning of fossil fuels. The problem is so big that sometimes, I don’t know where we can possibly begin.

We no longer have the luxury of waiting to act. While a dirty room is inconvenient and frustrating, the extraction and burning of fossil fuels threatens human life. Mountaintop removal, fracking and other extraction and refinement operations poison the air, water and land of communities with the least political, economic and social power. Island nations are disappearing, cities are leveled by superstorms and agricultural yields are dangerously impacted by record-breaking droughts. The harms of the fossil fuel industry are real and immediate. We must act now.

Every solution available to us that does not further endanger the environment or its inhabitants must be immediately and aggressively pursued. Actions that promote sustainability are a critical tool, and President Salovey’s sustainability plan is an important contribution. If Yale could establish a culture of sustainability and conservation, our campus would use less energy. And, taking an optimistic perspective, students might bring those behaviors and attitudes to their own communities and workplaces, expanding the benefits of sustainability.

But those benefits are inherently limited. If Yale decreases its consumption of fossil fuels, it will contribute to a necessary movement toward energy conservation, but it will not alleviate the air quality problems caused by the Bridgeport coal-fired power plant. It will not address the destruction of land caused by mountaintop removal in Appalachia. It will not address the poisoned water near fracking wells. It will not address questions of climate justice.

Moreover, spillover potential from sustainability is finite. Even assuming that every Yale student commits to spreading a culture of sustainability, and even assuming that they successfully share these lessons with everyone they meet, there are people and places that we will not reach. Perhaps more importantly, spillover takes time. And we don’t have time.

Local solutions are no longer enough. Climate injustice is built into the very infrastructure of our country, and we must pursue every solution at every level available. That is part of the reason that divestment is such a powerful tool. It strengthens the voice of institutions and communities in the climate movement. Participating in a global movement carries those voices and perspectives to the international level, increasing the range and speed of spillover.

More than that, though, divestment challenges the root of the climate problem. Rather than addressing the immediate causes or symptoms of climate change, divestment addresses the reason why these crises exist in the first place. In challenging the fossil fuel industry, it criticizes a system that privileges profit over the environment, a system that puts a price tag on human life. It challenges the displacement of the worst impacts of the extraction and burning of fossil fuels onto the communities with the least power. It allows us to imagine a better future.

Divestment fills a space that sustainability cannot. It is important to address the energy crisis from an energy perspective. But we also need to address the social and economic foundations of the climate crisis. To pretend that sustainability could ever be enough distracts from the urgency and depth of what is truly a global problem. We can no longer afford to live in the Yale bubble and pretend that isolated individual or community actions are enough. We need to engage in collective action that rises above the level of energy discourse to challenge the foundation of the energy crises. We need to divest.

Hannah Nesser is a junior in Branford College and a member of Fossil Free Yale. Contact her at