How to build a carbon footprint tracker

This is a submission for Weekend Challenge: Earth Day Edition What I Built Carbon Lens is an AI-powered carbon footprint tracker that lets you see the environmental cost of everything you buy. Point your camera at a grocery bag, upload a photo of a receipt, or type in a list of items — and Carbon Lens will instantly estimate the CO₂e footprint of each item, color-code them by impact level, and suggest lower-carbon swaps. The goal: make carbon awareness as easy as taking a photo. Most people have