These are the CASSE blog articles on materials use.


Introducing the Natural Resources and Electricity Cap-and-Trade Act

by David Shreve

In cap-and-trade systems, the government places a “cap,” or limit, typically on pollution or resource extraction. The amount of pollution or extraction is then divided into “allowances,” which are allocated to the polluting or extracting corporations. These corporations can trade their unused allowances in the marketplace.

Cap-and-trade policies promise significant abatement at an optimally low cost. But does experience with cap-and-trade systems vindicate this promise?

The United States and other countries have tested a variety of cap-and-trade systems.


Circularity in the Gold Sector

by Ramachandran Kallankara and Vivek Vivek

Twenty years ago, visionary economist Herman Daly exhorted the readers of Scientific American to create new ways of thinking towards a sustainable economy:

“The global economy is now so large that society can no longer safely pretend it operates within a limitless ecosystem. Developing an economy that can be sustained within the finite biosphere requires new ways of thinking.”

Economies are triangular,


Influenced to Overconsume: How Social Media Hijacks Sustainability

by Priya Thompson

We live in an age defined by contradiction. On one hand, the climate crisis demands urgent and systemic action. On the other hand, we are more connected to a digital world that profits—at great ecological cost—from our distraction, desires, and deeply human need to belong.

This tension is constant and personal for many Gen Z users, who overwhelmingly identify with sustainability as a lifestyle and a moral imperative.


Corporate Conservation Funding: A Contradictory Conundrum

by Kali Young

Apple, Cargill, Walmart, United Airlines, Chevron, BlackRock, Starbucks, Ford Motor Company, Amazon, McDonald’s, Sotheby’s…What do they all have in common? They are among many megacorporations that fund Conservation International, one of the most prominent conservation foundations in the world. World Wildlife Fund and the Conservation Fund, also conservation powerhouses, have similar though less expansive funder profiles.

Walmart and BlackRock are two of the world’s top deforestation perpetrators.


Introducing the Sustainable Housing Act: Shelter for All in a Steady State

by David Shreve

Housing in the United States (and in many other nations) is plagued by many problems and shortcomings. Among the most critical are increasingly unaffordable prices and bewildering geographic cost variations. Connected to these are additional problems associated with forced sprawl, the needless destruction of vital ecosystems, and labor market rigidity.

The residential cost problem is paramount and can no longer be dismissed as a predicament limited to isolated markets.


Peruvian Gold: Producers, Consumers, Lands, and Livelihoods

by Alix Underwood

When I say “gold mining,” what comes to mind? Perhaps you think of the 19th-century gold rush, with prospectors in suspenders swinging pickaxes and panning for gold in rivers. Maybe you envision industrialized mining, with terraced pits and heavy machinery. A visit to the Peruvian Amazon, where gold mining has surged in recent decades, transformed my perception of gold mining and miners.

I have the privilege of advising a team of Notre Dame master’s students—diverse in origins and expertise—as they work alongside a Peruvian NGO,


Maybe We Should Be the Ones Grokking: Thoughts on Elon Musk’s xAI Super-Polluting Supercomputer

by Helene Langlamet

Is it just our filter bubbles? Or is an understanding of the environmental impact of artificial intelligence (AI) slowly making its way into the mainstream? Recently, a spate of news stories have highlighted the hefty environmental footprint of AI. Take for instance this recent article by the Washington Post on the hidden water footprint of using AI chatbots. Or this article by The Guardian on how the greenhouse gas emissions of data centers may be almost eight times higher than large technology companies like Google or Microsoft will acknowledge.


San Jose: An Information Economy Giant with Whopping Footprints

by Alix Underwood

What is your reaction when you hear the tagline “city with the highest GDP per capita in the United States”? Perhaps you would like to live in that city. Perhaps you think it sets a positive example for other cities. If so, you are not alone. Corporate and political leaders have been prioritizing economic growth for decades, and this mindset has trickled down until it has saturated the public.

The problem is that there is a fundamental conflict between economic growth and environmental protection.


Two Cheers for Circularity

by Gary Gardner

Here’s some bad news for folks who see a circular economy as a way out of the polycrisis: Trends in global materials use, which recently bent modestly in the direction of circular flows, are flattening once again. The Circle Economy Foundation in Amsterdam reported in January that secondary materials amounted to only 7.2 percent of all materials in the global economy in 2023, down from 9.1 percent in 2018.


How to Avoid the Scarcity Scare

by Gary Gardner

In congressional testimony last November, Isabel Munilla, an official from the Department of Energy, gave an alarming assessment of U.S. reliance on foreign minerals. For 31 of 50 critical minerals, she warned,”…the U.S. relies on other countries for more than 50 percent of our requirements…Our reliance on non-allied foreign sources for these materials is neither sustainable nor secure.” Munilla employed what we might call the “scarcity scare”—the panic that supplies of critical minerals may be insufficient for all nations to participate in the transition to clean,