With pressure from organizations like the International Energy Agency and the United Nations calling for a concerted effort to reduce emissions and address worsening climate change, many have argued that data centers can make a difference by taking action to reduce their environmental impact.
Data centers worldwide use significant amounts of energy and resources to fuel power-hungry servers, yet at the same time, demand for data center services continues to rise globally. This is an ongoing conversation across the industry today, both in the C-suite and on the data center floor. But to have an effective conversation that leads to better data center sustainability, consider how data centers use resources and how that's affecting the environment.
5 ways data centers affect the environment
There are various areas of environmental concern that show the depth of the issues data centers face.
1. Energy usage
Data centers consume vast amounts of energy and electricity to power everything from servers, storage and networking equipment to the infrastructure that's supporting these devices. Servers require significant energy to function.
Many data centers have tens of thousands of servers and IT devices, all of which need electricity to run and process data-intensive workloads. According to the U.S. Department of Energy, data centers are one of the most energy-intensive buildings, consuming up to 50 times as much energy per floor space of a typical commercial office building.
According to the International Energy Agency (IEA), data centers account for 1–1.5% of global electricity use. Global data center electricity usage in 2021 was 220–320 Terawatt hours, which equates to approximately 0.9%–1.3% of global final electricity demand. This is a 10%–60% rise in data center energy use compared to 2015.
That said, the rise is not terrible when you consider that data center workloads have increased by 160% in the same time frame. This is largely thanks to improved energy efficiency and power usage effectiveness (PUE), which has helped data centers keep up with rising demand while mitigating the impact to the environment.
However, these efforts are not good enough, according to the IEA. Data centers and data transmission networks are responsible for nearly 1% of energy-related greenhouse gas (GHG) emissions, which contribute to rising global temperatures and climate change. To get on track with the Net Zero Emissions by 2050 Scenario, emissions must be cut in half by 2030.
2. Water consumption
The primary ways data centers consume water are directly through cooling processes to prevent servers from overheating and indirectly through electricity generation.
A typical cooling system comprises a variety of equipment -- from cooling towers and chillers to piping and air conditioning -- aimed at maintaining temperatures. Most equipment uses evaporative cooling that removes and releases heat within a data center into the outside environment and cools new air coming in. Humidifiers may also be used to maintain appropriate humidity levels -- a process that often utilizes electricity to vaporize water.
According to Google, an average Google data center consumes approximately 450,000 gallons of water per day -- roughly the same amount of water used to irrigate 17 acres of turf lawn once. That's in the middle of the spectrum. The full range encompasses smaller data centers that may use around 10,000–15,000 gallons per day to hyperscale data centers that may consume millions of gallons daily.
In addition, data centers are often established in drought-stricken areas. For example, NBC News reported on a data center Apple was approved to build in Arizona in 2021. This data center would require up to 1.25 million gallons of water every day to keep the servers within from overheating.
Where data centers are sourcing their water is also an area of contention. Many draw from potable water sources -- drinkable water maintained by water utilities. Google, for example, only uses non-potable water at 25% of their data center campuses. Use alternatives to freshwater where possible, like reclaimed or recycled water, especially in water-starved and water-scarce areas.
3. Electronic and toxic waste
According to the United Nations, electrical and electronic equipment that is disposed of incorrectly is known as electronic waste, or e-waste. This waste stream can directly affect externalities, such as resource consumption, GHG emissions and the release of toxic substances.
In 2019, the world generated 53.6 metric tons (Mt) of e-waste, the UN said. The global generation of e-waste grew by 9.2 Mt since 2014 and is projected to grow to 74.7 Mt by 2030 -- almost doubling in only 16 years. Around 8% of e-waste ends up in landfills or incinerated. E-waste can contain toxic additives and hazardous substances. In middle and low-income countries that don't have adequate e-waste management infrastructure in place, e-waste is often hard to manage and abate safely.
Improper management of e-waste also contributes to global warming. For example, the refrigerants found in some temperature exchange equipment are greenhouse gases. A total of 98 Mt of carbon dioxide (CO2) equivalents were released into the atmosphere from improperly discarded air conditioners in 2019. This equates to approximately 0.3% of global energy-related emissions. Since data centers can house tens of thousands of IT devices, it's important they set an example of how to reuse, refurbish and recycle outdated or broken-down equipment.
4. Land use
Where data centers are built and how they are built can impact the environment. Smaller data centers may take up 100,000 square feet, but larger data centers may require millions of square feet. That's a lot of land that needs clearing, which can wipe out biodiversity in an area and have other unintended widespread effects.
Take, for example, the data center proposal named the Prince William Digital Gateway in Prince William County, Virginia. Establishing the data center would require rezoning 2,100 acres of land. According to Bay Journal, more than 30 regional and national organizations, including the National Park Service and Virginia Department of Forestry, said the project's impacts could be irreversible and have long-term tangible and intangible environmental costs.
5. Greenhouse gas emissions
Greenhouse gases are gases that trap heat in the atmosphere. Such gases include the likes of CO2, methane and nitrous oxide. When trapped, these gases can stay in Earth's atmosphere for different amounts of time, ranging from a few years to thousands of years. This thickening of the Earth's atmosphere makes the planet warmer.
According to The Intergovernmental Panel on Climate Change, there are significant reasons for concern for global warming above 1.5° C. In short, it could result in drastic changes to our climate, including everything from extreme weather to complete species extinction.
CO2 is the primary GHG emitted through human activities, mainly through the combustion of fossil fuels, such as coal, natural gas and oil. The actual construction of data centers can also be a major source of GHG emissions.
How to make data centers more sustainable
Data centers can employ a variety of strategies to decarbonize and start down the path of sustainability.
- Invest in renewable energy sources and more energy-efficient equipment to optimize PUE. Virtualization can also reduce the burden on physical equipment.
- Commit to a water strategy, use alternative water sources where possible, and explore different approaches to cooling.
- Develop disposal plans to reuse, recycle and break down old equipment in non-harmful ways.
- When constructing a new data center or renovating an old one, use locally sourced materials that have less embodied carbon, like limestone instead of concrete.
- Calculate your GHG emissions to track progress toward climate goals. Carbon capture and sequestration can also help greatly reduce CO2 emissions.
Understand how your data center uses resources and how that's affecting the environment. From there, stakeholders can work together to rebuild and redesign data center infrastructure to be more eco-friendly and sustainable over the long term.
