As well as enabling devices to run longer, software can also be made more carbon efficient when it is operating.
Mobile phone apps have to be energy efficient because the phone has limited battery power.
But much software runs on servers in datacentres, where there are no such limitations on power consumption.
“You never even think about how much electricity you use when you’re building server applications, so you don’t do anything to optimize for that,” says Asim Hussain, executive director, Green Software Foundation. “There’s hardly any tooling to even measure it.”
The Software Carbon Intensity (SCI) specification helps to measure the carbon footprint of software and, earlier this year, became a global industry standard, external. The calculation at its heart includes both the emissions from the software operating, and the embodied carbon from the hardware it runs on.
The idea is to have a carbon intensity score that software developers can use to track progress as they try to drive down the emissions from their software.
The specification was created by the Green Software Foundation, whose more than 60 members include Microsoft, Intel and Google.
“We describe green software as software that is energy efficient and hardware efficient, which means it uses the least amount of physical resources possible, so there are less embodied emissions,” says Mr Hussain.
“We also include carbon aware, which means doing more when the electricity is clean and less when it’s dirty.”