Thanks. If you're comparing the new technology to the old technology, what you do is take a look, and you calculate the emissions of every single chemical that's involved in both technologies, including making the materials needed for those technologies. Then you calculate all those chemicals that are involved, good and bad, and how much is going to be released of each of those chemicals into the environment during manufacturing or use, or whatever.
Then you ask how much ozone depletion that is going to cause; how much global warming it is going to cause; how much toxicity to fish is going to be caused. All of these different environmental impacts are calculated for all those chemical releases from process A and process B. Then you sum them up and ask in terms of global warming, which process is better; in terms of smog formation, which process is better. You have maybe 10 or 20 different environmental impacts and you compare which process is better, the old one or the new one. If on the bulk of that, the new technology is less impactful than the old one, then the new one is green.