Decades of progress in energy-efficient and low-power design have successfully reduced the operational carbon footprint in the semiconductor industry. However, this has led to increased embodied emissions, arising from design, manufacturing, and packaging. While existing research has developed tools to analyze embodied carbon for traditional monolithic systems, these tools do not apply to near-mainstream heterogeneous integration (HI) technologies. HI systems offer significant potential for sustainable computing by minimizing carbon emissions through two key strategies: “reducing” computation by “reusing” pre-designed chiplet IP blocks and adopting hierarchical approaches to system design. The reuse of chiplets across multiple designs, even spanning multiple generations of ICs, can substantially reduce carbon emissions throughout the lifespan. This paper introduces ECO-CHIP, a carbon analysis tool designed to assess the potential of HI systems toward sustainable computing by considering scaling, chip let, and packaging yields, design complexity, and even overheads associated with advanced packaging techniques. Experimental results from ECO-CHIP demonstrate that HI can reduce embodied carbon emissions by up to 30% compared to traditional monolithic systems. ECO-CHIP is integrated with other chiplet simulators and is applied to chiplet disaggregation considering other metrics such as power, area, and cost. ECO-CHIP suggests that HI can pave the way for sustainable computing practices.