Data Centers’ Impact on Climate Change May Be Overblown, New Study Suggests

Researchers argue that new technology and greater efficiency could offset energy demands

Photo: Andia/Getty Images

The climate impact of the data centers that host the internet might be overstated, a new paper argues.

For those who spend much of their lives online and care about the future of life on Earth, one of the most alarming realities of the digital age is the climate impact of data centers, giant computing factories that host the web and serve as clearinghouses for internet traffic. Some experts have projected that the energy needs of data centers, which already account for about 1% of global electricity production, will skyrocket in the coming years, thanks to our insatiable appetite for online videos, cloud storage, music streaming, and more.

But other scientists think the narrative of heat death by server farm is overblown, and they’re pushing back in a new perspective paper published in Science. These researchers say that dramatic improvements in the efficiency of data centers have kept their power demands in check over the past decade and that there’s room for more efficiency gains in the future. Some question this conclusion, claiming that the data behind it is spotty and that gains in efficiency won’t match the rise of energy-hungry sectors such as cryptocurrency and online gaming.

What’s not in dispute is that data centers are energy-hungry beasts — a large facility can require as much power as a small city — and demand for their services is rising exponentially. It’s logical to assume that increased use of data centers will cause their power needs to grow in tandem. Indeed, several analyses have found that data center energy consumption is rising fast, doubling over the past decade, with the potential to more than triple in the 2020s.

The authors of the new paper believe studies that use data center demand to project power consumption have a fundamental flaw: They don’t fully account for improvements in energy efficiency. These include better data center cooling technologies, improvements in computer processor efficiency, and a shift from local servers toward cloud-based service providers operating so-called hyperscale data centers.

“Data center energy use has gone up, but it’s a very modest increase compared to the growth in data demand.”

Unlike other research in this field that relies on measuring IP traffic to estimate data center electricity, the authors of the Science paper used a bottom-up approach, compiling data on server sales and equipment efficiency. The new approach resulted in a surprising conclusion: Over the past decade, global data center energy usage was nearly flat, rising just 6%. At the same time, global data center “compute instances” — a measure of how many applications are running at once — grew 550%.

“We wanted to admittedly set the record straight about what we think the data is suggesting,” lead study author Eric Masanet of Northwestern University told OneZero. “Data center energy use has gone up, but it’s a very modest increase compared to the growth in data demand. These efficacy gains have delivered big gains globally.”

What’s more, the authors’ analysis suggests that today’s data centers have yet to max out their potential efficiency. Future technological improvements, they argue, could keep pace with the next doubling of data center demand.

Other researchers are doubtful of this rosy picture. Anders Andrae, senior expert of life cycle assessment at Huawei whose work has projected that data center energy demand could surge, pointed to different data and studies suggesting energy consumption may already be higher than the new study reports. Gary Cook, global climate campaign director at Stand.earth, also pointed out that estimates for data center energy demands vary widely, citing a lack of transparency among the companies building and operating them. In his view, the authors’ bottom-up estimates aren’t capturing the situation on the ground in places where new data centers are coming online rapidly.

Furthermore, Cook said, while efficiency improvements are “definitely happening,” greater efficiency tends to encourage greater use, an effect we’re seeing play out in areas like video streaming, online gaming, and bitcoin mining. (Although the climate impact of video streaming might be overstated.)

“There seems to be a disconnect from their methodology to what’s actually happening in the world,” Cook said. “Efficiency is actually driving much higher utilization of data.”

Masanet agreed that there could be data gaps. “There is a great lack of data on data center energy use,” he said, while adding that he thinks their data is “about as good as it gets” right now. He also agreed that efficiency improvements were driving more data center use and warned that if computationally intensive technologies like A.I. take off, energy demands could rise substantially. And the new analysis didn’t look at bitcoin-mining servers, which have eye-popping power needs on their own.

Chris Adams of the Green Web Foundation said that the paper’s conclusions are “broadly consistent” with his own experiences and research. But he also said researchers need to look more closely at the lifespan of the servers inside today’s mega data centers, which could have a dramatic impact on their carbon footprint.

“This is one of the reasons I agree with the calls for more transparency, as I think we aren’t seeing the whole picture here,” Adams told OneZero.

Everyone seems to agree that the future energy needs of data centers are difficult to predict and that efficiency improvements can’t keep pace with rising demand forever. To help keep data centers’ climate impact in check going forward, the authors suggest that governments could encourage adoption of efficiency standards, like Energy Star, through procurement programs and invest more research dollars in advanced computing, data storage, and cooling technologies.

It’s also crucial that new data center energy needs are matched with renewable energy: In theory, if every data center in the world was powered by the wind or sun, the sector’s climate impact would be negligible. Companies like Apple and Google have shown some leadership here, while others, like Amazon Web Services, are often criticized for failing to build enough renewables to keep pace with their data center growth.

Masanet said he’s expecting the new paper to get critiqued, but he hopes skeptical reactions spur more research into the energy and climate impact of data centers.

“We’re entering a new era,” Masanet said. “Data centers are only going to become more important, and energy use is likely to rise. And we need better research for monitoring this sector moving forward.”

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