Apple today shared an iPhone X environmental report, detailing the smartphone's environmental performance as it relates to climate change, energy efficiency, material efficiency, and restricted substances. 

The report reveals that the base model iPhone X generates an equivalent of 79 kilograms of carbon dioxide over its life cycle, which is the highest estimated greenhouse gas emissions of any Apple smartphone since the iPhone 6 and iPhone 6 Plus. 80 percent of the emissions come from production of the device. 

A comparison of Apple's estimated greenhouse gas emissions for each iPhone model:

iPhone X: 79kg CO2e

iPhone 8: 57kg CO2e

iPhone 8 Plus: 68kg CO2e

iPhone 7: 56kg CO2e

iPhone 7 Plus: 67kg CO2e

iPhone 6s: 54kg CO2e

iPhone 6s Plus: 63kg CO2e

iPhone 6: 95kg CO2e

iPhone 6 Plus: 110kg CO2e

iPhone 5s: 65kg CO2e

Apple said the iPhone X's U.S. retail packaging contains 55 percent recycled content. 100 percent of the fiber in the device's box is sourced either from recycled content, bamboo, waste sugarcane, or responsibly managed forests. 

Like other models, the iPhone X has a mercury-free display made with arsenic-free glass, and it's also free of BFR, PVC, and beryllium. 

iPhone X received a highest-possible gold rating from EPEAT, a program that ranks mobile phones based on environmental attributes in accordance with UL 110. All models since the iPhone SE have also achieved gold ratings.

Source: macrumors