Good coding practices for performance and efficiency have been part of software engineering since the earliest days. “When we were programming mainframes, every character counted,” says Sanjay Podder, chair of Green Software Foundation, an organization that aims to build a trusted ecosystem of people, standards, tooling and best practices for green software.
But over the past few decades, the overwhelming need for speed and productivity pushed architectural efficiency concerns to the background. Computers that piggyback on vast libraries with extraneous lines of code, developers who have lost count of the number of virtual machines they have spun off — all add drag and increase the carbon emissions related to software. These emissions include both the energy that physical hardware consumes to run software programs and those associated with manufacturing the hardware itself.
While a typical email might have a footprint equivalent to 0.3 grams of CO2 emissions, software that requires high-performance computing and AI have large carbon costs. The IT and software industry is projected to contribute 14% of greenhouse gas emissions by 2040.
As companies develop and use computing-heavy AI algorithms they must counterbalance this growth with legitimate decarbonization efforts. As a result, CIOs and the rest of the C-suite may soon find themselves under greater pressure to address the questions: How do we develop green software? How do we even know it’s green?
Green Software Foundation was founded to help with these answers.
The foundation’s beginnings
In 2021, Asim Hussain, executive director of Green Software Foundation, was the green software advocate at Microsoft. On a parallel track, Sanjay Podder ran Accenture’s Sustainable Technology Practice. When Podder published an article in The Harvard Business Review, he drew broader attention from industry leadership. Accenture asked Podder to do something about the problem. Today Podder is technology sustainability innovation lead at Accenture.
When Hussain and Podder met at a Sustainability Hackathon as jurors and realized the positions of their two organizations were aligned, they knew they had to collaborate. Other large organizations were also interested. All agreed that instead of having bilateral or trilateral agreements, it would be more efficient to form a foundation.
Founding members — Accenture, Microsoft, Thoughtworks, GitHub, Goldman Sachs, WattTime, The Green Web Foundation, and Leaders for Climate Action — launched Green Software Foundation, whose mission is to reduce the total change in global carbon emissions associated with software. The foundation started in 2021 and has more than 60 members today, a mixture of corporates, academia, and nonprofits, all working together toward the same goal.
A drive for actionable solutions
Well before Green Software Foundation got its start, when climate stewardship was only a conceptual idea, companies routinely published Corporate Software Responsibility (CSR) reports and issued press releases about their commitment to sustainability. But these efforts were short on actual quantitative accomplishments, and critics were quick to call them out for “greenwashing,” alleging the announcements served only to improve the organization’s optics.
Green Software Foundation’s steering members were convinced that practices around creating more sustainable software need to be actionable, not simply well-intentioned. This proactive approach to green software aligned with the foundation’s own goals. “We were not going to be crying babies” about climate change, Podder recalls; “we were going to be solution people.”
Those “solutions” directly reduce carbon emissions through carbon-efficient and carbon-aware software engineering practices — not by relying simply on carbon offsets. The founding members clearly set the foundation on the path for direct interventions.
Software can reduce carbon emissions by using fewer physical resources (fewer CPU cycles, less access to memory, disk, or network, etc.), by using less energy, or by using energy more intelligently. Companies can choose to consume electricity that’s generated using lower-carbon sources, or otherwise accelerate the energy transition toward a low-carbon future.
The foundation encourages more of these actions to be taken across the software industry.
First stop: Understanding green software
Right out of the gate, the foundation found that although many individual developers had the desire to improve sustainability at the grassroots level, their organizations as a whole were not effective at pursuing a holistic policy to implement wider change. Awareness was low; the principles of green software were not well understood, and they varied significantly from organization to organization.
So the foundation had to produce nothing less than a culture change, from top to bottom, by increasing awareness and education within its own member organizations so it could then turn its attention outward to the industry at large.
One of the first orders of business in increasing awareness: getting developers and companies to understand what green software really is. Instead of reinventing the wheel, the foundation reviewed a course in the concepts of green software that Hussain had developed while at Microsoft. To provide an easy first step for organizations to take, the foundation borrowed from Hussain’s materials and created a new basic training course, “Principles of Green Software Engineering.” The training is only two or three hours long and level-sets students to the same playing field.
The course has already been taken more than 70,000 times. It introduces key concepts and terminology that forms a common language, an important step to create cultural change inside organizations.
Standardized measures for ‘green’
One of the biggest pain points with respect to green software is developing a standardized measure of its sustainability.
Such measurements can be a regulatory requirement or help companies gauge the success of their sustainability initiatives.
When it comes to software development, computing inefficiencies (and carbon footprints) are more visible — bulky libraries for example — and engineers can improve it more easily. Everyday business operations, on the other hand, are a tad opaque but still contribute to the company’s overall sustainability score. Case in point: The carbon footprint of a Zoom call is harder to measure, Hussain points out.
The foundation helped to define a Software Carbon Intensity (SCI) score, which applies to all business operations including software development and SaaS programs employees might use. The SCI is now an ISO standard.
The SCI score is especially valuable because it equips CIOs with a tangible tool they can use in implementing green initiatives. Using the index, the CIO can measure the SCI score for every application and set specific goals. For example, “If I am responsible for the Zoom application, and you’re telling me the SCI score is so much carbon per minute per user, then I can report that and use that measure as a target if I want to reduce this measure 10% over last year,” Hussain says.
Measuring the SCI score is easier said than done, however, and the foundation is developing ways to make it easier. It has identified many software tools, most of them open-source, and is guiding steering members and any other organizations who might be interested in their use.
Working with the C-suite
In corporations, conversations at the C-level invariably boil down to the bottom line and how to square the return on investment in green software with the aims of corporate citizenship.
With the latest era of AI and GPU chips, the bottom line is more squarely in the crosshairs. The software industry’s concerns about efficiency are rising again. In April 2024, Meta CEO Mark Zuckerberg said that energy constraints have become the biggest bottleneck to building large AI data centers.
Large utility bills for high-performance computing are hitting home. Corporations now have an even greater incentive to take a closer look at greener software that guzzles less energy. And that will mean incorporating green coding practices into the very DNA of the product, in early stages for software development.
It turns out, says Podder, “that green practices correlate very well with just writing good software.” And, as the C-suite is realizing, green software also correlates really well with the bottom line.
