Digital technology has transformed our daily lives in dazzling ways. With just a few clicks, we can process massive amounts of data, connect with people across the globe in real time, and even watch AI write text or generate images. However, behind all this convenience lies a hidden shadow: enormous energy consumption and carbon emissions.
Take data centers, for example. Around the world, they already consume as much electricity as some entire countries. A single inefficient line of code or an unnecessary computation, when repeated across thousands of servers, can result in staggering energy waste. Training large AI models like GPT-3 is even more resource-intensive, requiring thousands of GPUs running nonstop for weeks. The carbon emissions from that process alone can reach hundreds of tons, comparable to those of the airline industry.
But that does not mean that developers and engineers are powerless. On the contrary, there is growing momentum to make computing greener. From code optimization and data center efficiency to lightweight AI models, a wide range of technical innovations are paving the way toward more sustainable digital technology.
In the early 1990s, the IT industry faced a new challenge: standby power. People realized that computers and monitors left on but unused were wasting enormous amounts of electricity. In response, the U.S. Environmental Protection Agency introduced the Energy Star certification. Back then, green computing began as a local effort to reduce unnecessary consumption at the level of individual devices.
Thirty years later, the situation looks completely different. The focus is no longer on personal PCs or monitors. The explosive growth of cloud services, data centers, and AI has created a new challenge: large-scale inefficiencies across the entire digital ecosystem. Today, green computing is not just about improving efficiency. It has reemerged as a business paradigm that can determine the survival of companies.
According to the International Energy Agency (IEA), global data center electricity consumption is projected to more than double, rising from 460 TWh in 2022 to 1,050 TWh by 2026. That is roughly equivalent to Japan’s entire annual electricity use. Driving this surge is none other than artificial intelligence. Training a single large model like GPT-3 consumed about 1.3 GWh of electricity, comparable to the daily power use of hundreds of thousands of households.
The paradox is clear: the more AI advances, the larger its carbon footprint grows. This has already become a social issue. Communities are pushing back against new data center projects, and in some cases, energy shortages are forcing operators to relocate. These conflicts show that green computing is no longer just a technical concern.
At the same time, ESG initiatives and regulations such as the EU’s Corporate Sustainability Reporting Directive (CSRD) are turning green efforts into a corporate obligation rather than a choice. Beyond ticking boxes in a report, energy savings have become a vital signal of trust for both investors and consumers.
A small change in code can make a huge difference. In one study on optimizing the Linux kernel, just 30 lines of modifications reduced the power consumption of network applications by 30 percent.
Algorithm choice also matters. Instead of comparing every name one by one in O(N²) fashion, using a method like O(N log N)—which sorts data in advance and searches only where needed—affects not only speed but also CPU usage and power consumption. Even the programming language you use has an impact. Research has shown that C is more energy efficient than Python.
Microsoft’s carbon-aware Windows Update feature is another example of this philosophy at the development stage. Rather than updating at random times, it schedules updates when the local power grid has a higher share of renewable energy, such as solar. The same update, timed differently, can significantly reduce carbon emissions.
Data centers measure energy efficiency using metrics like PUE (Power Usage Effectiveness). PUE is the ratio of total facility energy consumption to the energy consumed by IT equipment. The closer the number is to 1, the more efficient the data center. Google has improved its operations dramatically by lowering its PUE from 1.22 to 1.1.
Cooling system innovation is also crucial. Immersion cooling, which submerges servers in a non-conductive liquid, achieves heat transfer efficiency up to 3,000 times higher than traditional air cooling. This approach not only addresses the heat generated by high-performance AI chips but also helps reduce energy consumption.
AI is both a major consumer of energy and a potential solution. Model optimization lies at the heart of Green AI.
Comparison of AI Model Optimization Techniques
Google DeepMind has also used machine learning to control cooling systems in data centers, achieving a 30 percent reduction in energy use. It is a striking example of AI’s dual nature—capable of both consuming and conserving massive amounts of energy.
In the 1990s, green computing was mainly about reducing standby power. Today, it faces far bigger and more complex challenges: data centers, artificial intelligence, and global regulations.
Efforts such as code optimization in development, innovations in data center operations, and lightweight AI models may seem separate. Yet they all lead to the same fundamental question:
“How can we run the digital world we are building with less energy and fewer carbon emissions?”
Green computing is no longer an outdated environmental campaign. It has become the default consideration for building a sustainable digital future, as well as an essential strategy for companies and engineers to gain new competitive strength.