Understanding the difference between upstream and downstream emissions is crucial in achieving sustainability. These terms describe two distinct phases in a product's life cycle that impact carbon emissions.

Upstream emissions refer to the greenhouse gas (GHG) emissions that occur during the initial stages of a product's life cycle. For instance, consider the life cycle of a smartphone. Upstream emissions include the mining of metals, manufacturing of components, and transportation to the assembly plant. Reducing upstream emissions involves sustainable sourcing and eco-friendly production methods.

Conversely, downstream emissions occur during the latter stages of a product's life, including usage and disposal. In the case of a smartphone, the energy consumption during its use and the emissions during disposal are considered downstream emissions. Minimizing these involves designing energy-efficient products, advocating for responsible use, and promoting effective recycling or disposal strategies.