We’ve heard all the ways smartphones are potentially ruining us: by spreading illness, advancing obesity, shortening attention spans and contributing to poor eyesight, but a new reportreveals that they’re bad for the planet as well.

Research by German manufacturer Viessmann finds that using your mobile phone for just one hour a day for one year produces more carbon emissions than two round-trip flights between London and Glasgow — amounting to some 1.4 tons of carbon dioxide.

And while 12 months may seem like a long time for one person, consider that some two-thirds of the world’s population — about 5 billion people — use a cell phone these days.

The report also discusses the carbon footprint of other everyday tasks: boiling a kettle produces about 70 grams of CO2; an hour of television on a 32-inch LCD screen equals about 88 grams; driving a mile in an average car makes about 710 grams; and enjoying a steak costs some 2,000 grams of CO2.

The carbon emissions from cell phone use are generated by wireless network servers and data centers, where smartphones access apps, maps, texts and more.

Pew Research Center estimated that 92 percent of adults — approximately 228,000,000 Americans 18 and up — in the US had a mobile phone (including non-smartphones) as of 2015.  If Viessmann’s claims are true, that would account for some 319.2 million tons of CO2 a year. And in 2014, the EPA reports that the US produced around 5.5 billion tons of carbon dioxide, meaning cell phone use could account for between 5 and 6 percent of total carbon emissions in the country.

Cell phones and other tech are some of the biggest emissions offenders. Research by McMaster University in Canada found that greenhouse gases produced by the information technology industry could account for 14 percent of global emissions by 2040, up from just 1 to 2 percent about a decade ago.

“People are beginning to open their eyes and see that if we continue to live the way we are, our planet won’t be able to cope,” the Viessmann report authors say.