Nearly half of the carbon footprint of our digital world has been hiding in plain sight. A landmark study published in January 2026 in Communications Sustainability, a Nature Portfolio journal, analyzed a full decade of global economic data and found that digital industries are responsible for 4.1% of global greenhouse gas emissions—roughly 2,141 million metric tons of CO2 equivalent in 2021. That's a significant number on its own. But here's what makes this finding especially consequential: